# Question
Title: Is there a tool that generates my parts database?
I have many LEGO sets (mostly Technic) and I would like to build a list of parts (including colours). Is there an online service that does that for me based on the set IDs?

# Answer
> 7 votes
Both BrickLink and Brickset maintains a database. Brickset pulls data directly from LEGO's servers, which means the data is not always accurate for older sets or brand new sets (when the parts are not uploaded to LEGO's servers yet). BrickLink's parts list is maintained and meticulously verified by volunteers, and it is the most accurate of all LEGO databases. This includes both old and new sets.

Go to BrickLink.com, click "Sets" on the Homepage, and type in the set number you are looking for. Click on "Item Consist Of", and it will give you a list of all the parts in the set, including parts names, IDs, colors, year of release, weight, etc.

While BrickLink is the largest online LEGO marketplace, and it is mainly meant for buying and selling LEGO, you can also use it as a database for the sets and parts you own. This is very useful if you have a large collection, and can come in handy for evaluation and insurance purposes, or if you ever decide to sell your collection (or parts of).

Brickset is also great for maintaining a database of your collection, but as mentioned above, it is not the most reliable as far as parts lists. The focus is mostly on collectors being able to catalogue the sets they own. In addition, Brickset gives you a full value of your collection based on original retail price (vs. the current market prices given by BrickLink), and has some other useful tools. I recommend using both sites, but if you only want to use one, I would suggest BrickLink. It will give you everything you need to catalog the parts you have.

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Tags: sets
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# Question
Title: What set are these parts from? Tan walls and arches with green shutters?
Can you help me identify this Lego set? I don't know what set it is or how to build it!!

# Answer
> 5 votes
That looks like bag five of the Friends "Summer Riding Camp" from a few years back. I'd guess it's the stable to the left hand side of this picture:

The combination of the dark green shutters and medium lavender plates were my driving clues.

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Tags: set-identification
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title: LEGO Train - what size cork track bed

text:
# Question
Title: LEGO Train - what size cork track bed
What size model train cork track bed should I buy to fit under a standard LEGO train track?

# Answer
LEGO trains typically use a 2x8 plate for their sleepers (ties), with a stud protruding from each rail, giving a 40mm centreline gauge for the track and 64mm width for the sleepers - this is 5.5mm wider than O-Gauge - so might be a little hard to find off the shelf.

Lots more detail can be found on L-Gauge.org.
> 6 votes

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Tags: trains
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# Question
Title: Can't identify this LEGO set with large angled brown plates
Can any one help identify this LEGO set?

Because I can't find instructions to build it!

# Answer
I think you have some of the parts for Jabba's Sail Barge #75020

It is one of the few sets to have so many of the Hinge Plate 2 x 4 with Pin Hole and 3 Holes in light bluish gray, you show 7. It also has the 12 x 3 Wedge Plates in reddish brown, as well as the reddish brown 2 x 3 Tile with 2 Clips, and reddish brown 2 x 14 plates.
> 10 votes

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Tags: set-identification, star-wars
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# Question
Title: Which LEGO set did these small tan, grey and tan bricks come from?
Can anyone help me identify this LEGO set?

I just opened the bag and those are all the pieces, I don't know how to build or how to find instructions.

# Answer
> 9 votes
Those are mostly fairly generic pieces, however the 4x8 in Medium Blue only appears in 7 sets, and of those only Tower Bridge has any 1x8 in Reddish Brown.

This is part of 10214-1: Tower Bridge

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Tags: set-identification, advanced-models
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# Question
Title: LEGO identification from white, grey, and blue pieces?
I have these LEGO parts, can anyone help me identify this LEGO set?

# Answer
> 1 votes
I think this is part of 9525-1: Pre Vizsla's Mandalorian Fighter

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Tags: set-identification, star-wars
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title: Buyer security on BrickLink

text:
# Question
Title: Buyer security on BrickLink
I'm interested in buying LEGO bricks from BrickLink; the inventory is impressive, prices are good, and it is recommended by many LEGO builders.

Since you buy from unknown sellers abroad, I want to minimize the risk of scams or getting disappointed in some other way. What steps can I take to minimize this risk, especially concerning the payment method? Generally speaking, how big of a problem is non-serious BrickLink sellers?

I don't see much discussion of this at all on BrickLink's How to buy page.

# Answer
> 8 votes
As a buyer on BrickLink you place your order to the seller, who then must acknowledge your request and quote you a full price (including any taxes, shipping costs, or other fees; most buyers will lists these additional cost details on their individual seller page) if you don't like the price they quote, you can walk away. If you agree then you need to give them the money.

Most of the payments on BrickLink are processed through PayPal, which for all of its many faults, consistently sides with buyers over sellers in cases of disputes, so you can not only dispute any problems using BrickLink's resolution tools, but also with PayPal to get your money back.

BrickLink also has a feedback and reputation system you can use to check a sellers previous sales; so you can see if the buyer has any negative feedback or problem orders, but also it can show you how much volume they are processing. Someone making a lot of sales is likely to take the process very seriously. BrickLink tends to take non responsive sellers NRS or non paying buyers NPB very seriously, if you receive 3 of these complaints your buying or selling privileges will be permanently revoked, so someone with a large positive BrickLink reputation, likely isn't having these problems. BrickLink has a whole section on Problem Resolution you could read through if you are concerned in how the different processes work.

Also, if you are concerned about buying from another country, BrickLink allows you to filter sellers based on country. Buying from only your country will likely limit what is available, but it can make the process simpler in terms of shipping, customs, and different currencies.

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Tags: shopping, bricklink
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# Question
Title: How can I identify LEGO sets from a box or bag of parts?
I am a lifelong LEGO Maniac, and my kits from when I was a kid were passed down to my nephew, who has just passed them down to my son (40 years of history...).

The trouble is that none of my old plans/directions are still around, and neither are the plans/direction from my nephew's kits. My nephew and I started to do a quick inventory, but he couldn't remember all of the kits that were in the hoard (three *large* boxes so far).

Is there an easy way to figure this out? Does LEGO offer any of their old plans for free online or will I need to pay for them?

Can anyone offer help in identifying some of the fairly recent stuff? I can post images if needed. Some of the newer parts are quite unique.

# Answer
Your best shot is to identify an individual piece and look it up on Rebrickable, BrickLink or BrickSet. Since these all carry set inventories, you'll be able to find lists of sets in which the parts can be found. Try to start with more unique parts, chances are they are in a few models only.

Once you're sure you've found a model for which you've all the parts, build it using the instructions from LEGO.com or for older models instruction scans Rebrickable.

If identifying LEGO parts proves too difficult for some of them, ask experts.
> 25 votes

# Answer
## Find for the rarest piece(s)

My usual method for identifying a set I'm not familiar with is to find the rarest part. It's not always possible to find the rarest part but I can usually guess which parts are rare given how many of them I have in my collection.

For System sets I will usually ignore unmodified bricks, plates and tiles in common colours.

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**Example**

When I was trying to find the set in the example shown below from this question. I ignored all the plates and the two black 1x1 studs as they were all common parts in standard colours.

The only two parts remaining were the blue Minifigure Seat (4079) and the blue Steering Wheel (3829).

From those two parts it was easy to identify it as a vehicle and with the arrangement of the pieces I could tell it was a four-stud wide vehicle. Since around 2005-2010 it has become more common for LEGO to produce vehicles 6 or 8 studs wide so I assumed it was a fairly old set.

To identify these two pieces I used the catalogue search on Bricklink, if I didn't know the name of these pieces I could have search by category, or if I knew the piece number (found often on the bottom of many parts) I could have searched for that as well.

Every piece on Bricklink has a list of 'Known Colors', the steering wheel had 222 set entries for the colour blue and the steering wheel had the minifgure seat had 68 results for the colour blue.

I sorted the list by selecting 'Year Released' to 'Up' so that I would see the oldest sets first and set the preview mode to 'List with Images' so that I could see both a photo of the set and relevant information. (I also recommend using 'Thumbnail Gallery').

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**General Tips**

* The colours that I consider 'standard' are Red, Yellow, Green, Blue, Black and White. These colours are probably the most common and are almost always included in bulk brick buckets.
* Around **2004**, the colour of light/dark grey and brown bricks were changed slightly. Modern grey bricks are often known as 'bley' because of their blueish tint. **Related:** What is the bley (blay) color?

**Minifigure Tips**

* There was only one variation of the head for Minifigures prior to **1989**, the classic smile head. This piece continues to be used for classic releases as well as Modular sets although it is not as common. We can rule out any 'non-classic' minifigure heads as being after this year.
* Minifigures with two-sided heads were not produced until **2001**.
* Minifigures with short legs were not produced until **2002**.
* The first minifigures with realistic skin tones were released in **2003**. Only yellow minifigures were available previously. **Related:** Why do some minifigs have yellow heads and some are flesh colored?
* Microfigures were first released in **2009**
> 21 votes

# Answer
There are a number of ways to start figuring it out, my method is as follows:

Try and identify some of the following:

Unique pieces
Unique minifigs
Stickers on pieces
Unique logos
Color schemes or unique colors

The minifigs, stickers and colors are usually enough at least point you to the right theme category (ie space, pirates, castle, city, star wars, etc.) and often will narrow it down even further. A logo or minifig is usually a giveaway of what set group you're looking for.

For example a recent bulk buy I got had a number of Joker images on tiles and a number of unique purple and green colors that made it clear there was a Batman themed Joker set in the mix.

From there you can look up parts lists on Bricklink or Peeron, as well as find directions for assembly. To narrow it down to a specific set and make sure you have all the parts.

If your not super familiar with the lego themes these sites will also give you a place to find them.
> 7 votes

# Answer
Lego has an online page that can be used to download manuals in PDF format. Unfortunately, the page mentions that manuals are only available for kits that were released in 2002 or later:

> We currently have over 3300 building instructions available onlinevwhich date back to sets packed in 2002.

You might want to contact Lego customer service to see if they might be able to direct you to other resources for these older kits. According to squidoo.com, Lego customer service can provide older instructions for a fee. That page also lists several alternate resource that you can search to find older manuals for free:
> 5 votes

# Answer
One very good way is to look for numbers on pieces, especially when they are printed. A number on a Lego piece is almost always the number of the set.
These often come in places where there is supposed to be a number; like license plates on cars. If you have a license plate brick with a number, that's almost 100% certain to be the set that the car belongs to.

There are exceptions; for example, the Lego trains from the eighties had a "timetable" sticker that listed several numbers; each number was the number of another train set. (In other words, each train had a separate entry on the timetable). If you find that sticker, you have either a railway station from that time, or a train set from that tine that included a timetable. But, this will still narrow down your search.
> 4 votes

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Tags: set-identification
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# Question
Title: Do LEGO part counts on boxes include spare parts, brick separators and instruction manuals?
I bought some LEGO sets recently and was wondering (for no reason), if the part numbers that are shown on the outside of LEGO boxes include (along with the number of parts needed to build the set):

1. The number of spare parts,
2. The brick separator (if one),
3. The instruction manual(s).

# Answer
1. No. Set 30476 (pictured below) says it contains 33 pieces, but the set contains 3 extra pieces in addition to the ones needed to build the set. I believe it has always been this way.
2. Yes. When LEGO re-released the Taj Mahal, it contained exactly the same pieces except for the addition of a brick separator. The part count on the set's box was also increased by 1.
3. No, excluding the extra pieces, 30476 (pictured below) has exactly the 33 plastic pieces the manual says it should have.

**Set 30476:**
> 12 votes

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Tags: piece-information, sets
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# Question
Title: Lego identification help! Red torso, lightsaber handle, and grey pieces?
What does this build? Can anyone help me with the instructions link?

# Answer
> 4 votes
In the top left corner you can see the back of this torso:

Torso SW Darth Maul Chest with Gray and Silver Collar and Belt Pattern / Printed Red Arms / Black Hands

So this is part of 75022-1: Mandalorian Speeder

# Answer
> 1 votes
Building on @Syberion's answer and identification of the set, you can find many PDFs of manuals on Lego's site: https://www.lego.com/en-us/service/buildinginstructions

You can search by the set number, theme, and/or year to find manuals.

For this specific set, here are the links:

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Tags: building, set-identification, sets, instructions, lego-group
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# Question
Title: What is the best way to sell complete used LEGO sets?
I have some used Star Wars LEGO sets (one is discontinued and has been for a while), some Marvel/DC LEGO sets, and some miscellaneous sets. What is the best way to sell these?

# Answer
Are you sure that your sets are complete? You should verify that no pieces are lost, either by building the set or by checking LEGO's parts database (can do that on Brickset.com). If pieces are missing, you may want to order these.

On BrickPicker.com you find current market values of sets, so you know what asking price to set. That site collects eBay price data regularly. Then select marketplaces; eBay is used a lot by LEGO investors and it has an international audience of buyers. When it's time to ship your items you need to take care packaging the sets properly. To some buyers the condition of the box will be of great importance.

As you can see there's a lot of work involved with LEGO selling, and if you want to make serious profits you need to get economies of scale in your business, not just selling one or two sets.
> 3 votes

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Tags: shopping
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# Question
Title: Can you identify these 20 year old LEGO sets? Castle pieces with red bird and tall staircase?
We have boxes of LEGO which our children used to play with but now the grandchildren want to build things. Can anyone recognize which sets we might have so we can look up the instructions?

# Answer
> 14 votes
It looks like the bulk of the parts are from The Chamber of Secrets (4730):

As Henrik mentioned, Sorting Hat (4701) is also present:

Jason pointed out that Dumbledore's Office (4739) is also present:

I thought it might be worth noting that these old Harry Potter sets are fairly valuable to collectors. The Chamber of Secrets alone in complete used condition is currently worth ~$100 USD.

# Answer
> 5 votes
That yellow round tile is from 4701 - Sorting Hat. There are other parts that make me think there's probably more Harry Potter, but none that I can quickly identify a set from.

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Tags: set-identification
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# Question
Title: What sets are these electrical parts from, dark grey bases and remotes with orange and yellow buttons?
I have been searching for a long time but I am struggling to find the origin for these parts. I think they are possibly Power Functions IR remotes & battery packs...?

Thanks for any help.

# Answer
> 4 votes
The Battery Boxes on the left are 5115 or 9831 (most likely the former) from the 9V system (immediate predecessor of Power Functions). These don't come from sets but were items that were available for purchase on their own.

The middle unit is 23323c01 Electric, Bionicle Motor Remote Control Receiver Unit, Complete Assembly (Manas) from set 8539 Manas from the Bionicle theme from 2001.

Finally, the two remote controllers on the right are item 23335c01 also from 8539 Manas.

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Tags: technic, power-functions, electronics
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# Question
Title: 70915 Two-Face Double Demolition excavator gun won't load
I just finished putting together Two-Face Double Demolition and I went to load the gun on the excavator but part #6097090 six shooter trigger is too tall for the bullets to be loaded. Any idea how I can load the "bullets" when they don't fit?

The picture on the box of the trigger shows just the trigger point and not that big circle where the bullets fit

# Answer
> 4 votes
It appears that you don't have the white round piece pushed in far enough. It should be sitting further in, so you can load the 1x1 round plates (bullets) over it.

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Tags: sets
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title: Turn on LEGO Mindstorms robot remotely

text:
# Question
Title: Turn on LEGO Mindstorms robot remotely
I'm thinking to build a robot using either NXT or EV3, then I can control it remotely via WiFi or Bluetooth from my office! It's not difficult to write the controlling codes, but how can I turn the robot on remotely? Any suggestion please?

# Answer
> 4 votes
I know for a fact (from reading the EV3 schematics), the only way to turn on an EV3 is by pressing the center button.

Here are some ideas to work around this issue:

* Create another robot that presses the power button.
* Create a mechanical device that causes the center button to be pressed all of the time, then create a mechanism to switch battery power.
* Solder wires in parallel with the center button and attach this to a device, such as a relay, that can operate the center button electrically.

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Tags: mindstorms, remote-control
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title: Any tips for aligning gears in LDD?

text:
# Question
Title: Any tips for aligning gears in LDD?
I'm trying to create the 42052 (Heavy Lift Helicopter), and other Technic sets. Aligning gears' teeth is relatively difficult, and the 'Hinge Align' tool rarely works. Please help!

# Answer
Use math.

Here is a simple example... Suppose we want to line up two 8 tooth gears. Start by placing two axles and one of the gears...

Since there are 8 teeth on the gear, we can figure out that the teeth are 360° / 8 = **45°** apart. So, to put the next gear on, the space between the teeth of the second gear needs to line up with the tooth of the first gear. This space is half way between the teeth, so we need to rotate the axle 45° / 2 = **22.5°** to make them line up. Select the hinge tool, then select the axle that does not have a gear yet. Notice that the hinge tool allows you to enter numeric values directly....

The axle is already at -180°, so we need to rotate it +/- 22.5° from there. Let's say, we want to rotate it clockwise. In mathematics, counterclockwise is positive, but apparently in LDD, clockwise is positive, so we need to add. We simply type in -180° + 22.5° = **-157.5°**...

Now, the axle is exactly where it needs to be to add another 8 tooth gear...

There are no collisions preventing the gear from being placed...

Now, the second gear is precisely aligned, making it easy to place additional gears.

**Tip:** All (modern) LEGO gears come with multiples of 4 teeth, so adding a gears at right angles will line up the same as gears in a straight line.
> 4 votes

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Tags: technic, gears, ldd
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# Question
Title: Can you identify this old set with LEGOLAND minifigs?
There is nothing written on the box and no LEGO logo anywhere. All the pieces that come with it are LEGO.

# Answer
It is one box from 364-1: Harbour Scene from 1975:

Here's what the particular box looked like in newer condition:

And here's the set freshly opened with your box slotted into its place. Your box is the top center one if you can't tell from the image.

Here's a video covering this set in detail.
> 7 votes

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Tags: set-identification, vintage
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title: Lego Racers in Special Box

text:
# Question
Title: Lego Racers in Special Box
I am trying to collect all of the Lego Racers sets in the unique box design that set 8121, 8120, 8119, and 8122 have. Does anyone know if those are the only four in that box design? Thanks.

# Answer
Set 8121, 8120, 8119, and 8122 are the only ones with a red box.

It also comes in black

See this link for a complete list of boxes

Catalog : Original Boxes: Racers: Tiny Turbos
> 1 votes

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Tags: racers
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# Question
Title: What LEGO set is this? White pieces, brick separator, and blue pilot Clone Trooper?
I can't identify this. What does this build?

# Answer
> 3 votes
The minifigure is 501st Clone Pilot (75004)

So it should be this set

Z-95 Headhunter

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Tags: set-identification
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# Question
Title: Identify LEGO set with black door, large sand arch, dark-sand bricks, and tan plates?
What does this build? It has a black door, large sand arch, dark-sand bricks, and tan plates.

# Answer
THese parts come from 10232 Palace Cinema, based on the black door and the two 8x8 wedge plates in Tan.
> 4 votes

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Tags: part-identification, set-identification
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# Question
Title: Do clear transparent pieces suffer from a yellow tinge over time?
Any idea if clear 1×1 round plates suffer from color differences? I recently got a bag of them and they appear to have a yellow tinge.

# Answer
> 1 votes
I have found that the clear pieces depend on the piece. Some of the thinner ones do yellow, but I have 2x4 Clear bricks that are not yellowed. I think it depends on the thickness of the ABS that was used.

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Tags: piece-information, colour, plastics
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# Question
Title: Can anyone identify these 1x1 round tapered pieces?
Can anyone identify these pieces?

Source: http://bsg.deckdesigns.de/minis/raptor/raptor.htm

Source: http://www.moc-pages.com/moc.php/26424

# Answer
> 5 votes
The first piece is 424 Technic Hub / Handle 1 x 1:

It's actually pretty rare, only appearing in 9 sets from 1995-2006, and likely to stay that way as it has a similar newer counterpart, 18654 Technic, Pin Connector Round 1L which probably replaces it.

I cannot identify what those bottom black inverted slopes are though. It looks kinda like Wedge 6 x 4 Triple Inverted Curved, but without the middle 2 studs up front.

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Tags: part-identification, instructions
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# Question
Title: Two Mindstorms touch sensors: how to determine which sensor was pressed?
I'm trying do make simple program. Two motors, two touch sensors. Sensor one increases speed, sensor two decreases.

The whole program works very well but only with one sensor. When I put some logic that has "Wait for sensor two" brick it just fools around.

The algorithm is very simple:

* Variable `i` \- counts times sensors being pressed
* Variable `Znak` (eng. sign) causes variable `i` to decrease if negative or increase if positive.
* Motor speed is calculated by multiplying `i` by 10.

How can I solve this kind of problem?

# Answer
> 5 votes
I found an answer. I read in a book that I can't fork in a loop. But I can do up to 4 separate threads. So I did 3 threads:

1. Running/changing motors speed based on a variable "i" which is changed in other threads.
2. Waiting for a touch sensor A being bumped and increasing var "i".
3. Waiting for a touch sensor B being bumped and decreasing var "i".

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Tags: ev3, mindstorms, ev3-g, sensor
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title: How are LEGO bricks categorized?

text:
# Question
Title: How are LEGO bricks categorized?
What are the names and categories of LEGO bricks? Is there a consistent naming scheme? Does Lego have an official name or identification for different pieces?

# Answer
> 32 votes
It's been worked out by multiple groups who decided on different systems. The disagreement is based on what information was publicly available from the Lego Group at the time, what pieces had been manufactured up to that point, and what features the category authors thought were salient.

To really appreciate the magnitude of the problem, just try classifying every part in your own collection. Make your own categories or try to follow somebody's elses. You will raise a lot of questions about how broad the categories should be. Everybody with a storage system goes through this.

## Existing Classification Schemes

* Consider BrickLink's categories, which are up to 188 categories containing 25,096 parts as of this writing. In this scheme, there are no subcategories, only 2 levels. The category Brick covers 70 parts, but has 7 co-categories like Brick, Decorated (1356) and Brick, Round (38). Brick, Round shares some close neighbors in a separate group, Cylinder(47) (both terms inherited from LDRAW, by the way.) You could reasonably argue about membership characteristics for classifying under Brick, Round or Cylinder or even whether there should be two groups.
* LDRAW, originated by James Jessiman), didn't categorize parts hierarchically, but for many parts the first word or two makes a genus. Programs such as http://mlcad.lm-software.com/ displayed some of these categories in a menu but invited you to think of the big list "like the rummage in the Lego box." As of this writing, LDRAW covers 5,377 parts.
* Peeron is an example of an exhaustive set database using LDRAW's part numbers and names. Peeron didn't introduce a hierarchy of its own.
* PartsRef, by Steve Bliss, a major LDRAW parts author, attempted to categorize the LDRAW parts hierarchically. It had 22 top level categories, for instance: Architectural, having subcategories like Doors. However the Plate category remained undivided and included all the plates with various protrusions.
* LEGO Digital Designer is a newer example with its brick palettes (sorry, I'm not a user.)
* Pick-a-Brick as of this writing uses 42 categories, some of which are very broad. For instance, "Brick, Special" is one category (currently 155 parts) that other schemes divide into various groups for round bricks, modified bricks, cylinders, hinges, cones, etc.
* Auczilla by Todd Lehman and Suzanne Rich (circa 1996-2000) had another exhaustive parts scheme that excelled in its use of geometric adjectives for part names, such as Half-Octagonal (debatable on math grounds) and Quarter-Round, Convex and Concave. The link is from Internet Wayback but shows the top categories.
* Finally, Technica (1999) was another attempt at classifying just Technic parts.

In the end, some parts are placed into categories primarily by geometry, others by function, yet others by historical origin. You could also conceivably group bricks by building function (I'm thinking of direction-changing rectilinear bricks) or even by simply the number of studs (I'm thinking of a Kanji dictionary.)

## Part Names Make Classification Muddier

Consider the language barrier: if you read Lego's English Pick-A-Brick names, you realize it's translated (from Danish). A major category is "Brick, Bow" also known as an Arch.

*Dome*

Consider 30367, LEGO's "Final Brick" filed under Bricks, Special. Perhaps they meant Finial? LDRAW calls it a Cylinder with Dome Top. BrickLink puts it under Brick, Round (remember BrickLink has both categories Cylinder and Brick, Round from its LDRAW heritage.)

*Jumper Plate*

Jumper Plate is one name that made perfect sense to Europeans but baffled Americans; to James Jessiman (Australian) it was a Plate 1 x 2 with 1 Stud. I recall Auczilla used the adjective Offset in there. In Pick-A-Brick it's now a Plate 1x2 With 1 Knob. Or should it be a tile because it's mostly flat?

*Loudhailer*

Then there are multi-purpose parts: describe 4349 geometrically and it's another cone. But it could be a Minifig Weapon, or just Minifig Utensil. In LDRAW, it's a Loudhailer and has no category as such. The American term would be a Megaphone but many know it as Star Wars Blaster.

Multiply this complexity by thousands, and you get an idea that the task of naming is never settled.

## Part Numbers

Many LEGO bricks have part numbers imprinted from the mold. This is now called a "Design ID" by LEGO. It served as the original basis for LDRAW part numbers. However, LDRAW invented its own numbers for parts with no number.

About the year 2000, LEGO introduced a 7 digit "Element ID" to designate a particular design in a particular color. These numbers began to be used internally at LEGO for Building Instructions software, and externally in LEGO Creator software products. They are now shown in official set inventories and in Pick-A-Brick.

## Conclusion

This should give you an idea why different name and category schemes don't align. We start by talking about the same LEGO pieces but we bring preferred names from childhood or later (I always referred and still refer to 1xN bricks as 1-bumper, 2-bumper, etc.) We group them according to geometry or function, but find new reasons to subdivide or revise to make the groups more intuitive. New parts challenge these categories. LEGO does not seem to have given the problem much thought or care, lumping parts into catch-all categories. I derive immense satisfaction from solving a problem of devising a part's genus and differentia, but I realize that just like in the taxonomy of living things, there is competition between systems, and endless revision.

# Answer
> 3 votes
Our categories are:

* brick
* shaped
* mechanical
* people
* people tools
* finish

Then L, M, S within each of these. **Brick** is any rectangular prism, flat or otherwise. **Mechanical** are any that can spin or move when connected. **Shaped** are not mechanical or brick. **People tools** are anything that fits in a LEGO hand, not otherwise mechanical. **Finish** are smooth pieces that can not hold another piece on top.

My kids are 9 and 7. Its taken us that long to come up with the system,slowly over time. I'm utterly disappointed with moms who think color sorting is comparably useful. My goal is to be able to find any piece easily when boys put together each set to sell in their 20's.

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Tags: part-identification, terminology, organisation
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title: What are these 1x2 clip and bar pieces?

text:
# Question
Title: What are these 1x2 clip and bar pieces?
I am not sure what this piece is and I need to know what it's called so I can find it on BrickLink.

# Answer
Those pieces are:

Plate, Modified 1 x 2 with Handle on Side - Free Ends

And

Plate, Modified 1 x 2 with Clip Horizontal on End
> 6 votes

---
Tags: part-identification, bricklink
---


# Question
Title: Technic Firetruck 8289 with different wheels?
I am a bit confused with the Technic firetruck set 8289. The photo on its box:

clearly shows it has the wheels 56145c02:

however, according to this photo from BrickLink

it has 6595c01:

In the parts inventory both wheels are listed, but the parts of 56145c02 are also shown as alternate parts.

My questions: Does this set have a "facelifted" variant? Is there an alternate box showing the set with the other wheels, or LEGO simply changed the content without changing the box?

# Answer
> 3 votes
The instructions show and Brickset lists 4496197: Rim Wide W.Cross 30/20 as the wheel rim of choice, which fits with the release year of the Fire Truck (2006) and the manufacturing dates of the rims (2006-2013).

BrickLink's "preferred" rim was only manufactured up to 2006, which might explain why it lists the pictured rim as an Alternative part - as that would have been included in later runs of the set.

---
Tags: technic, piece-information, sets, wheel
---


# Question
Title: Help identifying unusual Technic part, long beam with 4 studs on end
I have a large collection of parts and I came across this slightly chewed, possibly Technic, part. No numbers on it, just the Lego on the studs. It's 15 Technic holes and then a T-piece on the end with 2 studs either side. The head seems to have a slot through it. Any ideas?

# Answer
> 9 votes
That’s a crane-arm centre. It’s usually used in non-Technic sets together with the crane-arm outside to obtain a telescopic arm, e.g., for cranes or firefighter ladder trucks. The slit at the end is to insert a piece of string for using it as a cable crane.

Here's a picture showing this piece in use as the boom of a crane from 4552:

---
Tags: part-identification
---


# Question
Title: Why do sellers do lots of 'random' bricks?
I've often seen sellers of large lots split them up into (usually 100) piles of 'random' bricks to be sold that way - even if they got the lot in a more organised manner.

To me, personally, randomised lots like these are entirely unattractive and feel a bit deceptive (as pictures included usually depict the WHOLE lot).

What is the buyers/sellers incentive to sell LEGOs like this?

# Answer
> 7 votes
I think their rationale is simple: selling 10 smaller lots is bringing them more money than selling it all in one big lot. It might also be a way to mask the fact that there are very few good/interesting pieces in the lot; by splitting it up but using the full lot picture every purchaser hopes they might get the good pieces. Finally, there could be some deception going on ... if you see a picture with a lot of run-of-the-mill parts and some rare/expensive ones, and you buy the whole lot, you expect to get those pieces. If you buy a part of the lot, you have no way to validate that those special pieces were ever included (they could have gone to one of the other purchasers, or, and this is where the deception comes in, they might have never been included).

Edit: there might also be a more practical reason: cutting the lot up into certain sizes might allow the seller to ship using a favorable shipping rate (e.g. First Class Package in the US) versus a more expensive shipping method for the entire lot.

---
Tags: shopping
---


# Question
Title: What part in LEGO digital designer can be used for a tank track?
I'm using LEGO digital designer to model a LEGO tank. I don't seem to find parts that can be used to make the tank track and the inside wheels; I found a "caterpillar belt" but no wheels that can fit inside the track.

There is a part called "caterpillar track", and unlike the belt the track requires wheels of different diameter to fit inside it. Again, I can see the wheel for the wider end of the track but not the narrower end.

Are there any parts that can be used for tank tracks at all? Or should I look for an alternative solution?

# Answer
> 6 votes
The caterpillar track and belt are both fixed length pieces.

I would recommend the more versatile #57518 'Technic, Link Tread Wide with Two Pin Holes'. The part can be used to make a track as long as long as you like.

The tread is compatible with:

* #57519 \- Technic Tread Sprocket Wheel Large
* #57520 \- Technic Tread Sprocket Wheel Small

---
Tags: ldd, tracks
---


# Question
Title: Did any sets have lots of 1x2 smooth tiles with gauges on them?
1x2 smooth tile with red 82 and yellow and white gauges pattern

I've inherited some LEGO and strangely it has 28 pieces of the above tile. Is there a set that uses a lot of these tiles?

I can't seem to find anything with more than 1 or 2 of them used.

# Answer
> 1 votes
No. :)

I checked several "gauges pattern" tiles. There is no set with more than 3 of them.

---
Tags: set-identification
---


# Question
Title: How do I have an else in conjunction with an if statement with two conditions?
I can't find a way to emulate an AND statement in a switch statement:

```
if (angle >= 10 and angle <= 30)
   ;// do smth
else
   ; // this is what I want

```

Until now, I just nested two if statements, but now I want to introduce an else case, but I don't want to duplicate the statements in the else condition two times (one in the first if, the second one in the nested one).

Is there a better way?

# Answer
You can put all of the logic outside of the switch block and use the "Logic" input of the switch block. You can do exactly what you have described in pseudo code since there are "less than"/"greater than" blocks and an "and" block.
> 2 votes

---
Tags: ev3, software
---


# Question
Title: Different surface roughness of tiles. Quality issue?
Recently, I filled a PAB cup in the nearest LEGO store. Among other parts, I also took a lot of light bluish grey 2x2 tiles. The following image shows some of these:

However, reflected light reveals that the surface of the tiles can be quite different. This image (same parts as above) shows that there are obviously two types of tiles. One with a really smooth surface, with the stud ring on the underside visible from above. And one with a rough surface similar to brushed metal:

I am a bit surprised to see LEGO products with their sub-micrometer precision molds showing such behaviour. Are different production lines mixing here? Have you experienced other parts with different properties that should be the same?

**Update:**

Alexander O'Mara suggested to examine the underside, and indeed there are some patterns. First, the smooth tiles:

Now the "brushed" tiles:

You notice the groove above the word LEGO on the smooth tiles that the brushed tiles don't have. The number 3068 is of course the same on both. There is a lot number (?) in the format XX-YY with YY being underlined.

The smooth tiles all have XX-57 with varying XX (right hand side), the brushed tiles all have XX-49 with varying XX (lower side, next to the "3068").

So, what does that mean?

**EDIT:**

One observation: inside the bottom tube, the surface shows a structure in the smooth tiles, but no structure in the "brushed" tiles. This could mean that the 3068 tile consists of two pieces that are hot-glued together in the process: One part covering the upper surface and sides, and another piece with the bottom tube and inside. The upper, covering part (from which small pieces are stamped out) may itself have an upper and lower side with slightly differing roughness. Maybe the production process doesn't prefer which side is up, so sometimes a rough side can be seen, and sometimes not. This is only a theory.

Can someone point towards an answer?

# Answer
From TLG Customer Service (emphasis added by me for one possible explanation):

> I truly appreciate that you sent this to us so that we could see the variation in the parts. Being able to see the numbers on the inside was very helpful!
>
> We haven't had any reports about quality issues with this element for any of the pressings. I've actually taken the link you provided and, as you know, the LEGO® Quality Team takes the quality of our products very seriously, and our team will now be able to look at these images in the post and make further evaluations. **It could be that the mould was changed and the new mould hasn't worn smooth yet** but I can't say for certain that that would be the cause of the variation in the texture on the top of the tile.
>
> Please make sure the user doesn't delete the post so that our Quality Team can take a look.
>
> Thank you again for passing this important post along to us. We really appreciate it!
> 7 votes

---
Tags: piece-information, manufacturing, pick-a-brick
---


# Question
Title: Can you identify this LEGO board game with square paper tokens?
I have some of these cards which I found at the bottom of an old box of mixed LEGO and I am trying to identify them. I think they came from a game maybe?

I used to get the Bricks n Pieces magazine, but not sure if they are from that. I would guess they are from the 1990's. Each card is approx 1cm square...

I vaguely remember playing with them, but can't identify what they are from - nor can Lego themselves. These four are all I have left.

Can anyone help?

# Answer
found it at last...!

They are cards from this game from the 1990s

Space Police / Blacktron II / M:Tron Poster Game

https://www.bricklink.com/v2/catalog/catalogitem.page?G=921800
> 6 votes

---
Tags: part-identification, lego-games
---


# Question
Title: 2 Unidentified Printed Pieces, 2x3 Dark Grey Slope and Black 2x2 Tile
Below I attached two photos. I am not sure if they are from the same set or not. I was wondering what set(s) they are in.

# Answer
> 9 votes
The slope piece is Slope 33 3 x 2 with Insectoid Scope Pattern from 9 (or 10) Insectoid sets from 1998-99.

The 2 x 2 tile is Tile 2 x 2 with Insectoid Logo in Triangle Pattern from 9 (or 10) mostly-Insectoids sets.

There are a few sets with both pieces.

---
Tags: set-identification
---


# Question
Title: What set is this sealed bag of pink, purple, and white bricks from?
I would like help identifying this bag of pink and purple LEGO bricks. It has three sets of eyes.

# Answer
> 9 votes
Based on the White Plate, Modified 2 x 2 with Bar Frame Octagonal, Reinforced, Completely Round Studs and the Dark Pink Brick, Modified 1 x 2 x 1 1/3 with Curved Top

This bag is part of 10696-1: Medium Creative Brick Box

---
Tags: set-identification
---


# Question
Title: What are the dimensions of a technic axle?
I'm working on a LEGO compatible motor system that will be largely 3D printed. I want the connectors to fit standard LEGO axles, but I haven't been able to find the dimensions online, and I don't have any on me to measure. What are the dimensions of the cross-section of a LEGO axle. Is there a difference in size between the plus-shaped hole for and axle and the axle itself?

# Answer
> 12 votes
I found CAD files for LEGO technic axles here: https://grabcad.com/library/lego-technic-axles-1 and some gears which have holes for technic axles here: https://grabcad.com/library/lego-technic-gears-1

Using their online viewer I found the following dimensions (Which are a little inaccurate due to the limits of their online viewers tools. For more accurate and detailed dimensions download a copy of the CAD files)

This would seem to indicate (if accurate) an interference fit between the outsides of the axles and the holes (i.e. the hole is slightly smaller) which could be accurate as axles are usually tight.

Someone should also probably measure actual LEGO parts with some calipers for confirmation on these dimensions.

---
Tags: technic, gears, size, 3d-printing
---


# Question
Title: What is the selling rate per pound for individual colors?
I separated all my LEGO bricks by color so I can get max profit to pay closing costs on my family's home. Is there a going rate per pound for individual colors?

# Answer
Colour seperation matters more in which audience will be interested (AFOL's knowing they used some colour(s) more than others vs. parents wanting a pile for their kids) than for price.

Lots of things matter a lot more then the bricks being seperated by colour, some examples:

* Whether the bricks have play wear
* Whether the bricks have been miscoloured by sunlight
* Whether the bricks have been exposed to smoking
* The actual selection of bricks - i.e. are they all standard bricks or are they something less common in (some of) the pile(s)
* Where you are in the world
* ...

So we don't have nearly enough information to give a good answer.

They are other questions on the site where people give estimates.
> 6 votes

---
Tags: shopping, value
---


# Question
Title: What is the function of this device? What kit? Black remote with 5 buttons and 3 AAA batteries?
Some kind of IR device #s on cover 41305 #s on outside case 4252

LEDs appear to be IR transmitter and receiver. Red and white LEDs also seen.

# Answer
It's a Spybotics remote from 2002.

It came in 4 sets, and works with the receiver in those sets. I found this page which talks a bit about them.
> 4 votes

---
Tags: piece-information, remote-control
---


# Question
Title: Why do two EV3 bricks have different power outputs?
I have two identical box designs with EV3 bricks. When I upload the same programs to both, one moves about twice as fast as the other.

Is there a reason that this might be happening? Is there anything I can do to update it?

# Answer
> 2 votes
Some possible reasons:

* A motor is defective
* One of the brick has lesser battery charge
* Firmware problem: make sure both bricks have latest firmware

---
Tags: ev3
---


# Question
Title: Can't create block: "Use of a block which no longer exists"
> ```
> Unable to compile some documents for deployment:
> Program.ev3p: Use of a block which no longer exists.
> PutInRange.ev3p
>
> ```

The block I want to make. It will put a input value inside a given range. When I try to upload i always get a error. I already deleted every thing and started new. And always it will give me a error. The Lego software looks very buggy to me. Am I the only one that has these problems ?

This is the MinValue block that gives the minimal value of two.

This is the MaxValue block that gives the maximal value of two.

And this are the blocks in my program, and there all there.

# Answer
Try exporting(saving locally) the block that shows error. Then delete it from the program and import it from where you saved it
> 1 votes

---
Tags: ev3
---


# Question
Title: Does the Mindstorms EV3 software work on macOS Sierra?
I guess this is a **continuation** of these two questions:

Does the Mindstorms EV3 software run on OS X El Capitan?

Is the LEGO Midstorms EV3 software compatible with OS X yosemite?

macOS Sierra was just released, and I want to upgrade. Will there be issues with the software, or will it work properly?

My Mac: Retina MBP 13", Early 2015

# Answer
> 5 votes
I have a Mac Mini with macOS Sierra, and the LEGO software works on it for me.

# Answer
> 3 votes
FWIW, LEGO MINDSTORMS EV3 Home Edition was crashing on startup (latest Mac OS X Sierra du jour: 10.12.6 16G1113) — presumably (from callisto's answer) because my installed version of Mono was too recent. I uninstalled Mono by typing the following commands in a Terminal:

`sudo rm -rf /Library/Frameworks/Mono.framework
sudo pkgutil --forget com.xamarin.mono-MDK.pkg
sudo rm -rf /etc/paths.d/mono-commands`

Afterwards, I uninstalled and reinstalled LEGO MINDSTORMS EV3 Home Edition from its official source and I could successfully run it. FWIW, the version of Mono that LEGO MINDSTORMS EV3 Home Edition installs for itself is 2.10.9:

```
# ls -l /Library/Frameworks/Mono.framework/Versions/
total 8
drwxrwxr-x  12 root  wheel  408  8 mai  2012 2.10.9
lrwxr-xr-x   1 root  wheel    6 25 nov 12:46 Current -> 2.10.9

```

# Answer
> 2 votes
Beware though. If you install Xamarin on your OSX machine, it will grab the latest Mono framework which is NOT compatible with the EV3 software (I don't recall which MONO version is used by EV3 software).

I have contacted Lego support a few times, and they are not going to update their OSX software. You will either have to then use a different machine or a VM to run the EV3 software.

---
Tags: mindstorms, ev3, software, compatibility, mac
---


# Question
Title: Can you identify this 3x4 black plate with studs only going down the middle?
I need help in identifying this piece so that I can search for it on BrickLink. It is a platform for minifigures. It comes with the "mystery minifigure".

# Answer
You should be able to find this piece by looking up *any* of the collectible minifigures on Bricklink and looking at the set inventory.

This piece is the **Tile, Modified 3 x 4 with 4 Studs in Center (88646)**.

It is classified on Bricklink under the category 'Tile, Modified'.
> 10 votes

---
Tags: part-identification, collectable-minifigures
---


# Question
Title: Is the LEGO BOOST kit compatible with EV3 or PowerFunctions motors and sensors?
I'm curious if I can use my existing EV3 and/or PowerFunctions motors to extend the functionality of my LEGO BOOST set. Is this possible?

# Answer
> 8 votes
While LEGO BOOST is compatible with the bricks from other sets, the motor, distance sensor, and Move Hub are not electrically compatible with current EV3 or PowerFunctions components. BOOST uses the same six pin connector as WeDo 2.0 from the Education line:

So, the bad news is that you can't easily use PF or EV3 motors with BOOST. However, LEGO plans to use this connector for PowerFunctions in the future and possibly for the successor to EV3 as well, so there may be more compatible components down the line. Here's how it's explained in the WeDo 2.0 FAQs:

> **Is this a new plug system?**
>
> Yes, this is the new LEGO Power Functions plug that has been optimized also to meet potential future needs.
>
> **What does that mean for the existing plug systems on other Power Function and MINDSTORMS products? Will they also be changed?**
>
> Yes, eventually we will convert to the new plug system after a transition period. The exact timing of this transition has not been determined.

# Answer
> 2 votes
While the Boost components use a different connectivity, there is potentially another way you can extend your EV3 set with the capabilities of Boost by having both communicate via Bluetooth.

Unfortunately, there are no standard LEGO-provided tools to do so, but the systems are open-ended enough that some people are working on it. For example, here is a Python library which you can use on your EV3 brick running ev3dev (a specific debian distribution for EV3) and talk with the Boost hub. I haven't tested it myself but it looks promising.

---
Tags: ev3, power-functions, boost
---


# Question
Title: How to make Lego Mindstorms EV3 robot go in reverse when move steering input comes from proximity sensor
I saw an program on the Lego Education page which makes a Lego Mindstorms EV3 robot gradually slow down as it approaches a wall. The info from the proximity sensor is used as the direct wire input of the Move Steering block, the nearer the robot to the wall, the slower the speed of the robot.

The problem is that my infrared sensor is on the rear of my robot (track3r). I would like to make the input to the Move Steering Block negative so that my robot motor moves backwards (in reverse) using this program. How do I do this? I can't make the output of the proximity sensor negative... can I?

# Answer
> 5 votes
Multiply the output of the proximity sensor by -1.

---
Tags: ev3, mindstorms, programming, sensor, motor
---


# Question
Title: Good manufacturer/market for clear (transparent) bricks and plates in bulk?
I never realized how rare clear bricks are! I'm looking for an efficient way to buy clear 2x4 (e.g. 3001) bricks in bulk. On BO, BL, and Peeron there are very small lots and prices close to $1 and beyond per brick. On Alibaba there are some new compatible brands but they tend to mix random colors and styles, no pure bulk packs of the same brick in clear (white).

While I can patch together an order from the above, I'm wondering if there is a manufacturer that just sells pure lots of the same type and color so I can keep buying from them and not have it be a brand new search each time.

Or do any markets exist that unlike PL/BO/Peeron include competing brands rather than only Lego?

# Answer
> 6 votes
Clear 2x4 bricks might seem to be expensive because LEGO doesn't produce them currently (they stopped making them in 2006). However, a quick search on Bricklink sees them listed as cheap as $0.02 per brick, used, which is not expensive at all. Just make sure you look for the correct brick design - you want to look at 3001old.

---
Tags: shopping, clone-brands, bricklink
---


# Question
Title: Running Power Functions Train Without IR Receiver/Remote
I recently bought 10254 Winter Holiday Train and wanted to get it running around the provided circle of track. I was wondering if there is any way to do this without incorporating the IR receiver and speed remote? My understanding is that if I were to simply connect a battery box to the motor and switch it on it would run too fast and de-rail.

I suppose my question is ultimately; is there a way to limit the speed without using the speed remote? The train will only ever go around a perfect circle of track so I have no desire to alter the speed for straights/corners. I don't have a huge knowledge of electronics but can use a soldering iron and am willing to get my hands dirty.

I also understand that the rechargeable battery box has a variable speed output (which does sound ideal) but was wondering if there is a cheaper option?

# Answer
There is a fairly easy and cheap way to do this since you don't want real variable speed control. As you noted, connecting the AAA battery box directly to the PF train motor technically works, but the motor runs too fast.

The default AAA battery box provides 9v from 6 AAA cells. Lowering this voltage will lower the speed of your motor. If you'd like to get your hands dirty, you can modify the AAA battery box or buy a battery box that supplies another voltage and connect this up to the C0 and C1 lines of your motor.

However, the simplest solution I can think of is to purchase (or possibly build) AAA dummy batteries and use a few of these in the AAA battery box in conjunction with regular batteries. These look like AAA batteries, but are actually just metal conductors internally. By using a number of these in the battery box, you can have it provide 1.5v, 3v, 4.5v, 6v, 7.5v, or 9v.

Philo has a nice breakdown of speed vs voltage for PF train motors:

```
3V = 135 rpm (2 AAA batteries, 4 dummies)
4.5V = 468  rpm (3 AAA batteries, 3 dummies)
6V = 792 rpm (4 AAA batteries, 2 dummies)
7.5V = 1107 rpm (5 AAA batteries, 1 dummies)
9V = 1458 rpm (6 AAA batteries, 0 dummies)

```

You can make adjustments in 1.5 volt increments by adding or removing batteries from your setup to hopefully find a speed that works for you.

It's a bit more complicated/expensive to get proper variable speed control, but if you just want a constant speed that is slower than the default PF full speed, this is the simplest method I can think of.
> 6 votes

# Answer
LEGO train motors get powered using a 9V cable. Philo (who also visits this site) has an excellent site with all the features and characteristics about the PowerFunctions motor system, which includes trains. This site is located at http://philohome.com/tech.htm.

The speed of the train is regulated using PWM (Pulse Width Modulation) on the inside two wires (C0 and C1) of the power functions connector. If you feel adventurous, you can cut a PF cable and put electronics in between (an Arduino perhaps) to give the train a constant speed (perhaps read the speed from a pot-meter, this is how the rechargeable battery box works).

For reference, I've done something similar in my RFID controlled train, see my video on Flickr. Just a word of warning, unless you know what you're doing you're probably spending a lot of time on this and just forking out $50 for the rechargeable battery (plus either $30 for LEGO's adapter or $10 for a generic adapter (assuming you can regulate the voltage and the polarity of the pin)) might be the easiest and most cost-effective option.
> 4 votes

# Answer
Easy solution. Use 3 dead batteries, 3 new batteries. Achieved perfect speed.

Dead batteries are easy to find in kids toys :)
> 3 votes

---
Tags: trains, power-functions, customization, remote-control, electronics
---


# Question
Title: How much is Sheriff's Lockup #6755 worth?
I have set #6755, Sheriff's Lockup. What's an estimated value without the minifig?

# Answer
> 3 votes
Set 6755 is basically an older version of set 6764. There are several listings on that page missing all the minifigs - they seem to go for ~$40 (or at least those are the current asking prices).

# Answer
> 2 votes
BrickLink has a price guide that will give you both the current prices people are asking for sets as well as any details on those sets sold in the last six months.

If you can't find your specific set, you may well be able to find a similar one (either in the same theme or similarly sized) that does have the data you want.

Typically "new" or "new in box" sets will sell for substantially more than "used" sets, and licensed figures will have more of an impact on prices than generic minifigs if they are missing.

---
Tags: value
---


# Question
Title: What is the best way to transport a large quantity of LEGO bricks?
I have a decently sized collection (thousands of bricks/hundreds of sets/a bunch of bins) from my childhood, but they're all at my parents' house. I live in the US and a couple states away from my parents (more than 1000 miles). What is the best way to package all of the bricks? What is the best way to move all of those packages? I ask because I'm thinking the weight of them all might make it tricky to transport. Hopefully someone out there has been in a similar situation.

# Answer
> 5 votes
When I moved house, I just sealed the gaps in a bunch of packing boxes with duct/packing tape, and put the storage bins in there - that way if anything did escape from the bins it wasn't going to get lost from the box.

I would say though that in general my collection wasn't organised in anyway, although there were a few built sets that survived fairly well.

# Answer
> 1 votes
No personal experience, but one vendor I've seen a couple years now at Brick Fiesta just ships boxes full, roughly U-Haul medium sized. He has some cardboard 'trays', but I'm pretty sure they are not structurally useful. He also had stuff bagged up into various types and some level of sorting, but that's not really important to shipping either.

Of course, if you have some relatively delicate bits (like \[part:2337:46\]), take care to pack them with as little stress on them as possible.

(ok, clearly I'm not getting how to do part linking)

# Answer
> -1 votes
Pack them in a box and surround them with things that are soft.

---
Tags: storage, transport
---


# Question
Title: How should I transport my big LEGO sets?
I'm moving and I have some big LEGO sets (Police Station, Fire Station, and Ultra Stealth Raider). How should I pack them so they won't get shattered to pieces in transit?

# Answer
> 1 votes
You should disassemble the buildings to smaller parts, then pack these parts with bubble foils. After that, you can place them in massive plastic boxes. LEGO bricks aren't really fragile.

---
Tags: storage
---


# Question
Title: How do I see which stores have all the parts I want on Bricklink?
If there are four different parts I am wanting on Bricklink, is there an easy way to see if one shop has all four? I would want to get it from one shop to reduce shipping. I know I could do it the long way, but if I don't find one early it could take a while.

# Answer
The way to do it is to make a wanted list in BrickLink, selecting all the different pieces and quantity of each that you want.

Then select all of the items by checking the boxes next the items you want or selecting the upper box to select them all and then click the green buy items button, this then brings up a list of stores selling the items. The list is sorted by which store has the most of your selected items available to sell. The two important columns on this list under each store is "unique lots" which is how many of your different parts the store has followed by "item count" which is the quantity of those items they have.

If you then click on the individual store, their shop will have a wanted list tab, which will show you everything on your wanted list that they have to sell.

It's not uncommon to have to purchase from multiple shops to get everything (different items and quantity) you need/want. So it often requires checking multiple stores to combine it into the smallest number of purchases, I am not aware of any automated method of doing this, I just end up opening multiple tabs in my browser from the list of stores generated by my wanted list query and figure out the best option myself from there.
> 9 votes

---
Tags: shopping, bricklink
---


# Question
Title: Do all Technic bushes (3713) have the LEGO label on them?
I have just found out that many of my Technic bushes (3713) do not have "LEGO" printed on them. Does this mean they are fake?

I know that many parts were produced in several variations.

# Answer
Technic bushes didn't always have LEGO stamped on them.

I don't remember exactly when I first noticed this, but some years back they started stamping LEGO onto a bunch of different pieces that didn't previously have it.

I suspect they did this because people were knocking off more and more of their pieces.
> 8 votes

---
Tags: technic, piece-information
---


# Question
Title: I need download instructions for this set, but I don’t know the number, light green and black pieces
I need to download instructions for this set, but I don’t know the set number.

# Answer
> 6 votes
This bag is from 70736-1: Attack of the Morro Dragon

Based on:

and a double check with the instructions.

---
Tags: set-identification, instructions
---


# Question
Title: What are the set numbers for these Star Wars and Police sets?
I recently bought some old sets and stumbled across these 2 set-remains. One is obviously a Star Wars set, maybe someone knows the number? I wonder if the other one, the future police, is a MOC instead of an official set?

# Answer
The police vehicle is from 7035-1: Police HQ

The last picture is from 7748-1: Corporate Alliance Tank Droid
> 5 votes

---
Tags: set-identification, star-wars
---


# Question
Title: What causes certain LEGO parts to yellow over time, and how can this be prevented?
I've noticed that certain LEGO colors have a tendency to turn yellow over time. For example, I have a set of 4 "white" wheel hubs that are all now various shades of yellow:

I know there is already some information on how to fix this, but I'd like to understand why this happened and how to avoid it. What causes LEGO parts to turn yellow, and what specific steps can be taken to prevent this damage?

# Answer
> 8 votes
There are many things such as dirt and chemicals that can cause elements to change color. Dirt can easily be washed off, but certain contaminants such as cigarette smoke can stain plastic.

The most common issue that causes LEGO bricks to yellow is interaction with ultraviolet light, most commonly from the sun. The simplest way to prevent this is to store parts indoors out of the way of even indirect sunlight.

There are some tips for correcting this issue in another question, and more details about the chemical process that causes UV light to degrade ABS over on Chemistry.

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Tags: colour
---


# Question
Title: Which Lego Technic sets are officially combinable?
Lego sets 42058 Stunt Bike and 42059 Stunt Truck can be combined together to build a bigger truck. We can find official instruction on the LEGO site.

Are there other pairs (or larger groups) of sets like that?

I am particularly interested in Technic sets released in the last couple of years, but it would be great if there were a comprehensive list of such sets or a way we can search them.

# Answer
> 5 votes
Whenever a LEGO Technic set is officially meant to be combinable with another set, it is mentioned right on the box, as well as in the instruction booklet, and also in the official set description at the Online LEGO Shop. The combined instructions are posted at the LEGO Technic website.

As far as a list, I don't know of any place that has a comprehensive list like that, but I agree it would be very useful. I do know, however, that the two LEGO Technic Pull-Back Racers released each year since 2013 can always be combined with each other with downloadable instructions. Here is the list of the sets: https://brickset.com/sets/list-15258

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Tags: technic, set-database
---


# Question
Title: Which clone brand and set do these pieces belong to, rock platforms and castle walls?
Please help. What set is the rock platforms from and the other rock pieces? The castle walls too?

# Answer
> 2 votes
Most of these are mixed Mega bloks Dragons sets from the Dragons series.

The rock platforms are from Dragons: Raiders Keep #9650 (more pictures).

There is also a window from #9885 Marauder's Cliff.

---
Tags: piece-information, clone-brands
---


# Question
Title: What happened to Olivia in the 2018 Lego Friends sets?
If you've been following the information about the 2018 Lego Friends sets, you may have noticed that some of the characters look a little different. Most characters look fairly similar with minor updates. However, Olivia appears to now be a different race:

Olivia before 2018:

Olivia in 2018:

What is happening here? Has Olivia been replaced?

# Answer
Many adjustments have been made for 2018. The five main characters all still exist, but they have been changed somewhat. This was brought up on the Lego Ambassador Network, and generated enough interest to get an official response from the Friends team in Billund:

> Every year we strive to innovate and make our products even better for children all over the world. A lot of effort has gone into the development of the LEGO characters and universes across our entire product range, so it makes us very happy when changes are noticed.
>
> LEGO Friends in 2018 looks a bit different than what it has in the past. To be specific, the 5 main characters have a slightly different look but also the city and the citizens of Heartlake City have changed.
>
> But what are the reasons for the change?
>
> Firstly, we want to assure you that all 5 friends are still there in 2018. Andrea, Mia, Emma, Stephanie and Olivia – they all still exist! Also the character’s main interests and personalities remain mainly unchanged.
>
> What you will see in 2018 is an evolution of LEGO Friends, a progression of the story and characters to make sure children get an even greater play experience. Every year more than a million children and parents reach out to us and share what they love and what they would like to change. In the LEGO Friends range children told us that they would like even more differentiated characters and also suggested improvements to Heartlake City.
>
> We always take great care to listen to input from children, and the LEGO Friends team has worked hard to make even more engaging and relevant experiences for children – and also make the LEGO Friends universe more true to the actual world children live in.
>
> Taking a starting point in reality, we’ve made the characters more diverse in their appearance and have added more depth to their personality. And of course, they still live in Heartlake City. But just as the characters have changed, Heartlake City has become more differentiated and rich. There are different districts and there are other citizens that play a more active role in the story.
>
> The changes we have made does not change the fact that previous and new LEGO Friends sets will cater for great building and play experience in 2018 and beyond, and we hope to inspire even more stories and play opportunities for children in the future.
> 9 votes

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Tags: minifigures, friends
---


# Question
Title: Augment LEGO City Mobile Command Center 60139 with Power Functions LEGO 8293?
I have the LEGO 60139 set for my child. If I buy LEGO 8293, will I be able to motorize the truck in 60139 set?

# Answer
> 7 votes
You are not likely going to be able to add the power functions motor to this set without some major modifications. The truck in the set uses pin type wheel connections, the motors normally use technic axle style wheels, and there isn't really any extra room internally to place the motor.

For reference:  Set 60139

Set 8293

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Tags: power-functions, city
---


title: Lego Technic 42048 with LEGO 8293

text:
# Question
Title: Lego Technic 42048 with LEGO 8293
I have seen a YouTube Video that claims the motorization of LEGO Technic 42048 using LEGO 8293. However, the LEGO support site does not state such compatibility.

I am not able to get my hands on a physical box of 42048 to see whether the power functions symbol is on it.

Appreciate if anyone could share whether LEGO Technic 42048 can be motorized with LEGO 8293 straightaway, or if there are any special tweaks or pieces required?

# Answer
> 8 votes
Well the thing with LEGO, (Technic, Classic, Mindstorms or whichever category you talk about) is that it is customizable. You might not get instructions to combine Power Functions with this kit but you can figure out a way or look at other people who have done it. No, you cannot straightaway attach Power Functions with the 42048 set. There are sets (at higher prices) which have been designed to contain the PF elements. So no the power functions symbol is not there on the 42048 box.

However I encourage you to go ahead and try to attach the 8293 PF elements to any Technic set you have since you probably can fit the parts into most sets.

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Tags: technic, power-functions
---


# Question
Title: "Unable to compile" error code with LEGO EV3 Arm Robot Program
Does anyone know how to fix this error with my LEGO EV3 program?

```
Unable to compile some documents for deployment:
Program.ev3p: Use of a block which no longer exists.
INI.ev3p: A My Block cannot contain a copy of itself.

```

# Answer
I think the key phrase is "A My Block cannot contain a copy of itself." Look in the "INI" My Block for another copy of the "INI" My Block and delete it.
> 2 votes

# Answer
The main problem is that you have nested INI inside INI maybe cause you were trying to use recursion which EV3 does not support. It might also be that you have a copy of INI inside INI not connected to the play button script.

It may also be that your INI block contains another my block inside which contains the INI block in it and so on.

It would help if you uploaded the program or showed us snapshots.
> 0 votes

---
Tags: ev3
---


# Question
Title: What Technic set should I get for general Technic MOC?
I want to do some small machines in these books, But the sets recommended by the author are super expensive (set 8043 8053).

> LEGO Technic Sets I Recommend (December, 2010) Honestly, it is hard to find LEGO Technic sets which include a good variety of parts. Most include the parts you’ll need in order to make a particular model, like a car or helicopter. In addition, the sets available in the USA differ from those in Japan, where I live. Of the sets sold in the USA, I think the best set is #8043 (Motorized Excavator) ....

What are today's "equivalent version" of 8043 and 8053?

# Answer
> 4 votes
You should really buy the Lego Technic Bucket Wheel Excavator. It's a great price for the parts and has a very wide variety of parts: banana gears to Power Functions Elements.

---
Tags: technic, sets, moc
---


title: Clutch gear test

text:
# Question
Title: Clutch gear test
I have two white 24t clutch gears, one marked as 2.5-5Ncm and another unmarked - how can I assembled them in a way to test which one "gives" first ) i.e. has torque before it slips - I was thinking to lock the axle on both and then driving them through a differential, but I am not sure how "fair" or symmetric a lego differential would be for driving them, and also noticed that they don't have a constant torque, but rather a shifting amount depending on the position, so some way to determine both the peak and average torque of them would be ideal, but I am not sure of as to design such as test, thus this question:

How can I test two clutch gears to determine their differences?

# Answer
> 2 votes
This is an example. Just replace both black gears with the clutch gears you want to test. Hold 1 clutch while turning the main black axle. Then hold the the other clutch while turning the mail black axle. In one of them you will feel more friction while turning the axle. This clutch you are holding then is tighter/ offers more friction.

---
Tags: technic, building, gears
---


# Question
Title: What are good books for building techniques of LEGO Technic
I've been searching for good resources for especially LEGO Technic. I find the *Unofficial LEGO Technic Builder's Guide* by Paweł “Sariel” Kmieć. The book is very good at explaining things. Beside that one are there any other books that I can learn basic to advanced building techniques of LEGO Technic?

# Answer
In addition to Sariel's excellent book, I'd suggest Yoshihito Isogawa's "Tora no Maki" (Book of secrets) downloadable PDF book, and his Ideas books in print. All are full of clever mechanisms, easy to reproduce and integrate into bigger constructions.

See: isogawastudio.co.jp
> 12 votes

# Answer
Isogaway Yoshihito is without doubt one of the greatest "Technicians" of all time here are some books of his:

https://www.google.co.in/search?q=yoshihito+isogawa+books&oq=yoshihito+isogawa+books&aqs=chrome..69i57.191j0j7&sourceid=chrome&ie=UTF-8
> 2 votes

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Tags: technic, building, books
---


# Question
Title: What are these strange black disc LEGO pieces?
What are these discs? Ammo maybe or ice hockey pucks? I did not find any id numbers.

# Answer
That would be Sports Hockey Puck, Large:

It comes from the larger Technic-based Sports Hockey sets from 2003-2004.

(Puck in the above set has stickers.)
> 10 votes

---
Tags: part-identification
---


# Question
Title: Is there a way to buy just the robotic parts?
I apologize if this is a silly question. My kids recently went to a LEGO robotics workshop at our local science museum and LOVED it.

Is there a way to buy just the robotic parts (motor, sensors, software, etc)? We don't need anymore lego bricks, as we have them coming out our ears, lol.

I did see parts on ebay, but got overwhelmed since I really don't know about the different types and what is compatible. Is there a good place to learn about that?

# Answer
> 10 votes
Yes, you can buy all the electronic parts by themselves, but given that the electronic parts are the bulk of the cost, you may not save much.

The MINDSTORMS EV3 set (MSRP $349.99 USD) contains:

* `1` \- EV3 Intelligent Brick (MSRP $189.99 USD)
* `1` \- EV3 Color Sensor (MSRP $39.99 USD)
* `1` \- EV3 Infrared Sensor (MSRP $29.99 USD)
* `1` \- EV3 Touch Sensor (MSRP $19.99 USD)
* `1` \- EV3 Cable Pack (MSRP $14.99 USD)
* `2` \- EV3 Large Servo Motor (MSRP $24.99 USD each)
* `1` \- EV3 Medium Servo Motor (MSRP $19.99 USD)
* `1` \- EV3 Infrared Beacon (MSRP $29.99 USD)
* Software: Free download.

That comes to a total of: $394.91, or $44.92 over the price of the whole kit.

That means you would have to find these pieces for a fair bit less than the MSRP to save any money (remember shipping costs if you get them from multiple sellers), which could be difficult as these pieces tend to have good resale value. At quick glance on BrickLink, I found you can maybe get $40 of an EV3 Intelligent Brick, but the EV3 Medium Servo Motor is actually selling over the MSRP (possibly because it is backordered).

> We don't need anymore lego bricks

The Mindstorms kits actually come with LEGO Technic pieces, not bricks. You would not really be able to use these electronic parts without a fair number of Technic pieces.

If you plan to follow along with the instructions from the kit, you would need to have the parts in the kit.

---
Tags: shopping, electronics, robotic
---


# Question
Title: Is it possible to run more than two remote control trains on one track?
My son has two passenger trains and a lego cargo train. We can get two trains running on the track using one remote.

But how do you operate a third train? We do have other remotes which came with each train. Do you use a second remote or do you use the number settings and just use one remote?

# Answer
> 4 votes
Each remote has 2 separate controls (one for "red" and one for "blue"), and 1 channel setting (choice of channel 1,2,3 or 4). Each train has an IR receiver which has 1 channel setting (again choice of channel 1,2,3 or 4) and two connections, one coded "red" and one coded "blue". From what you describe, you have two trains set both to the same channel (I'm assuming channel 1) but for one train you connected the motor to the "red" connector and for the second train you connected the motor to the "blue" connector. Doing so you can control both trains independently from the same remote, also set to use channel 1 (one with the left control, one with the right control). For the third train, set the channel on the IR receiver on the train to channel 2, and then take another remote and set it to channel 2 as well. Take note of which connector on the IR receiver you used to connect the motor to (the "red" or the "blue" one) and then use that color control on the remote to control the third train.

Alternatively, you can use a separate remote for each train, and assign each remote a different channel (e.g. 1, 2 and 3) and each train IR receiver also a different channel, matching to the channels you chose for the remote (e.g. 1,2 and 3).

# Answer
> -1 votes
There is (as far as I know) only one channel available with LEGO trains/remotes

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Tags: trains, remote-control
---


# Question
Title: Why are there 4 wires leading to the Power Functions LEGO train motor?
Does anyone know what the wires do?

If the Power Functions train motors are simple DC only 2 wires would be needed or is it more complex than that?

# Answer
The LEGO Power Functions connectors have 4 standard designations regardless of the usage:

* 9V power
* "0V" Ground
* C1 "control 1"
* C2 "control 2"

It seems for motors that the 9V and Ground are unused. The C1 and C2 are used in combination to pick the motor direction. If C1 is providing power and C2 is providing ground then the motor goes forward. If C2 is providing power and C1 is ground then it goes backwards.

The dashed lines are unused at that stage in the flow.
> 11 votes

---
Tags: trains, power-functions, electronics
---


title: What to do with a 25K pc collection?

text:
# Question
Title: What to do with a 25K pc collection?
I know there are a lot of questions on how to sell your set, however, my situation is a bit different. I'm not sure whether I should sell my set at all vs. keep it.

I am currently spending a year in Israel and have started to recover my lego collection from my parents. Since I was a TeenageFOL/AFOL, as opposed to most people in their so-called "dark ages", I actually managed to keep hold of 99% of my former collection, which I'm guessing rivals some serious AFOLs' collections.

I estimate the collection approximately 25K pieces (not including approx. 3500 more that I currently have in the U.S., the bulk of the pieces are from the S.H.I.E.L.D. carrier). Here is a set list (last updated in 2001, hah):

http://guide.lugnet.com/set/mlist.cgi?m=88

I am now torn between the following options:

1. Bring the collection to the U.S. ...

a. ... for self-use, for me & my daughter as she grows up. This is possible, though it currently feels overwhelming due to the magnitude of the collection. Given its size, it feels like I would probably need to dedicate an entire room to it. Not exactly what I had in mind for my real estate needs, to be dictated by LEGO (though I'm 100% sure others in this community have done so!!!). I do not currently have a dedicated room in my house to do so. Also, I'm not really sure whether I would actually be drawn to building with it, as my hobbies have shifted over the years and are quite distinct from lego, though I will always love it. Also I know that it could be a huge gift to my daughter... but only if I can balance the desire to keep things meticulously sorted, and the tendency to jealously guard against messes and just general fun playing/building/destruction. I've seen that the ginormous amount of pieces is simply overwhelming for a child at her age (close to 4)... or almost any age.

b. ... and keep it in storage. This seems like a futile exercise, since it would probably cost me a fair amount in shipping costs. I do, however, have sufficient space for this without any additional changes to my current home. (Unfinished basement + outdoors shed if need be)

2. Sell the collection...

a. From Israel: that would allow me to save on two rounds of shipping

b. From the U.S.: I'm guessing that might give me much better options for buyers.

c. In bulk: would save a ton of time & energy. But clearly the collection will not be worth as much in bulk.

d. Sorted into sets and/or individual pieces: obviously should bring in more money but gosh, what a time sink. I'm a busy professional mom who hasn't spent any meaningful amount of time on Lego in years. Plus, I'm guessing there will be some or even many parts missing / discolored / damaged which will lower the value of the set-separated collection without further investment.

3. Leave the collection in Israel, i.e. at my parents' house, for the grandkids' enjoyment (but not my daughter). This risks further messiness / degradation of the collection by my nieces and nephews. Has the clear upside of avoiding headaches of all types, and the clear downside of letting go of huge amounts of money and love poured into the collection over my T/AFOL years.

I've read a lot of posts on this SE so far, which have been very helpful. Following that, I plan on using Peeron and/or Brickpicker to estimate the value of the sets I own, if sorted, to decide whether I'd like to sell it at all, and whether it's worth the time to sort (I'm guessing that aside from a few sets such as 10001, the answer is probably not). I really appreciate a few people mentioning the low reputation issue for selling on eBay, which I'll pay attention to should I decide to put up some of the rarer / more valuable sets for sale.

If you had to suggest a course of action from those I described above, which would you gravitate to?

# Answer
Since no one answered here, I will post an update on what I have done so far. I will update it in the future if that makes sense.

At this point I've recovered the collection to my apartment in Israel. I've started sorting the collection, mostly because after reflection I decided to reframe it as something actually fun to do, as opposed to a chore or something in order to make money (it would probably not be worth the value of my time). After I sort the collection I am considering rebuilding some or perhaps all of my old sets, see what condition they're in and whether and how many pieces are missing.

If there are any rare or valuable sets I may consider selling a few them. That said I have already seen firsthand how much my daughter is enjoying the collection, and it seems I will hold on to most or maybe even all of it. But I won't make a decision for sure until I am done sorting.

I asked this collection on Facebook and received a number of alternative suggestions that were not among those I considered initially:

* Donating some or all of the collection to organizations that work with kids
* Creating art with it
* Opening a LEGO rental business :)
* Giving some or all of it away to friends with kids

I will consider some form of hybrid options between these.

I mention these here in case they will help someone else with similar challenges.
> 2 votes

---
Tags: sets, shopping
---


title: Round Plate 1x1 Dimension

text:
# Question
Title: Round Plate 1x1 Dimension
What are the dimensions of the following Lego Part:

I know of the basic dimensions shown in this graphic.

I believe, the diameter of the largest Ring is 7.8mm. However, I'm missing the following two measurements:

* diameter of the base-cylinder
* height of the base-cylinder
* height of the small big middle cylinder

# Answer
You can derive detailed part geometry using the LDraw parts library. LDraw provides freely accessibly models for nearly every part that Lego has produced. I'd recommend parsing these parts rather than rolling you own models if you're going to be using many parts.

Here is the relevant content of the file representing a 1 x 1 round plate:

```
1 16 0 3 0 -1 0 0 0 -1.25 0 0 0 1 stud4.dat
1 16 0 3 0 -6 0 0 0 -1 0 0 0 6 4-4disc.dat
1 16 0 3 0 -2 0 0 0 -1 0 0 0 2 4-4ring4.dat
1 16 0 0 0 10 0 0 0 3 0 0 0 10 4-4cylo.dat
1 16 0 0 0 2 0 0 0 1 0 0 0 2 4-4ring4.dat
1 16 0 0 0 2 0 0 0 1 0 0 0 2 4-4ring3.dat
1 16 0 0 0 1 0 0 0 1 0 0 0 1 stud.dat

```

LDraw uses its own custom file format. Units are in LDU and represent about .4mm.

I won't try to describe the format in detail, but lines starting with `1` simply include another file that is translated, scaled, and rotated based on the included transformation matrix.

# Base cylinder

We can break the part definition down to its components. The outside of the base cylinder corresponds to:

```
1 16 0 3 0 -1 0 0 0 -1.25 0 0 0 1 stud4.dat

```

stud4.dat represents a ring that could fit a stud inside of it. It's present in many parts (e.g. underneath 2xn bricks and plates). It looks like this:

Its outside is represented as (from stud4.dat):

```
1 16 0 -4 0 8 0 0 0 4 0 0 0 8 4-4cyli.dat

```

The primitive 4-4clyi.dat (4 fourths of a cylinder) is a basic open cylinder:

Most LDraw primitives including this one are normalized size 1, so we start with a cylinder with height 1 and radius 1. A transformation matrix is then applied:

```
1 16 0 -4 0 8 0 0 0 4 0 0 0 8 4-4cyli.dat
            |               |
            +-------+-------+
                    |

                8   0   0
                0   4   0
                0   0   8

```

Now, it's a cylinder of height 4 and radius 8. This was also transformed by the original inclusion of stud4.dat:

```
1 16 0 3 0 -1 0 0 0 -1.25 0 0 0 1 stud4.dat

```

We need to multiply its height by 1.25 to get a cylinder of height 5 and radius 8. Here's the final result:

**Base height** = 1 * 4 * 1.25 = 5 LDU * .4mm = 2.0mm

**Base diameter** = 2 * 8 LDU = 16 LDU * .4mm = 6.4mm

# Middle ring

If you followed all of that, the middle ring is easy. It's outer wall is represented by:

```
1 16 0 0 0 10 0 0 0 3 0 0 0 10 4-4cylo.dat

```

So, it's a cylinder with a 10 LDU radius and 3 LDU height:

**Middle ring diameter** = 2 * 10 LDU * .4mm = 8mm

**Middle ring height** = 3 LDU * .4mm = 1.2mm

# Checking our work

The height of the base and the middle ring sum to 8 LDU, which is good because this is the correct height for a plate like this.

As you noted, you expected the outer ring to be 7.8mm, but I calculated it as 8.0mm. The reason for this is that LDraw uses the ideal sizes of bricks for its library. This is convenient for collision boxes in the theoretical world, but in reality, Lego has to make parts slightly smaller so that they fit between each other easily. As you mentioned, this tolerance is about .1mm per side, so we're in the right neighborhood with our calculations.

In addition, most things in LDraw end up rounded to 1 LDU, so measurements have a tolerance of around +/- .2mm. Most Lego parts fit very nicely into a 1 LDU grid, so this isn't usually an issue. I'm not sure what level of precision you require, but my hunch is that the LDraw library will get you close enough for your needs.

Good luck with your project, and let us know if we can help with anything else!
> 6 votes

# Answer
I have a micrometer for measuring with 0.1 mm precision. Using that I measured following lengths:

* diameter of top cylinder (stud): 4.9 mm
* diameter of lower cylinder: 6.4 mm
* diameter of middle ring: 7.9 mm
* height of middle ring: 1.0 mm
* total height of the plate: 5.1 mm
* inside diameter of lower cylinder: 4.9 mm (no surprise)

Can anyone confirm or question these lengths? I would be interested in knowing whether I did it right.
> 5 votes

---
Tags: size
---


# Question
Title: Building a more-efficient water propeller?
I enjoy making Power Functions-controlled boats to race (in water) in various LEGO convention competitions (which require 100% genuine LEGO pieces).

Usually, these boats end up being paddle boats, because of how inefficient all the LEGO propellers are. Supposedly Propeller 2 Blade Twisted (4745) is actually the most-efficiently shaped LEGO water propeller.

There are a number of problems with this propeller.

* The blade are thick.
* There is no good way to attack an axle to it.
* The shape of the blades is sub-optimal.
* It's on the small side.

Is there a way to build a more-efficient one, out of several pieces?

# Answer
The LEGO RC boat by Slewentogzz claims to have a top speed of 3 km/h, it uses a custom propellor built out of Technic parts.

The actual rudder parts appear to be Technic Panels #87080 and #87086. These panels are very common and are available in over 60 sets.

There are two more parts in a similar design (#64683 and #64391, they are one stud longer each so you can make a slightly larger propellor.

**Images:** Slewentogzz Lego Creations

**Video:** "Lego RC Boat with custom built propeller (3,0 km/h!)"
> 5 votes

# Answer
Rather than making your own propeller with piece- which might break under the stress of water- i recommend using a different propeller like:

More propellers: https://www.brickowl.com/catalog/lego-parts/vehicle/propeller
> 1 votes

---
Tags: building
---


# Question
Title: What sets are these pieces from, rock platforms and walls with large cannons
I think I have a couple of sets I'm trying to put together for my son that were my brother's when he was young. Probably from around year 2010 or earlier. Looks like a black castle or dungeon. Also with gargoyles and broken wire cells. Also have large rock platforms and rock walls. Please help. I've searched and can't even find the pieces online.

# Answer
> 3 votes
It looks like you have some Mega Bloks sets.

I can't say for sure if these are sets you have, but I found similar pieces in these sets:

**Dragons Battle Gate**

**Portal of Fire**

I don't know of any resources for non-LEGO instructions.

# Answer
> 1 votes
Red cannons from second foto from mega bloks pirates: Shark escape, Plunderer's port. Gold cannon was in many sets: Mutiny isle, Captain cutlass' stormstalker, Port royal

More dragon sets: Tower, Warriors fortress, Sorcerer's lair.

---
Tags: piece-information, clone-brands
---


# Question
Title: How can EV3 Gyro sensor drift be handled?
EV3 robots can use a Gyro sensor to determine the direction the robot is heading.

The initial conditions are important. The sensor needs to be still and then the sensor reset.

However, once in a while the Gyro returns values that drift over time.

What can be done to handle Gyro drift?

Step one would be to remove the drift using the

* Hardware fix: unplug the gyro sensor, make sure the robot is still, and then plug in the sensor.
* Software fix: Gyro Drift Simple Fix which should only need to be run once.

However, I'm aware of several FLL teams using this fix and even then, once in a while the robot goes crazy, because the Gyro sensor has acquired a drift.

Applying the Simple Fix at the start of every run does not seem to fix it every time.

Is there a way to handle this?

# Answer
> 5 votes
There are two options that I can think of.

1. Do the "hardware" fix before every run of the robot to reboot the sensor along with the "software" fix to zero it.
2. Don't use the Angle reading at all. To calibrate the sensor, sample the rate (d/s) 10 times or so and take the average to get the "at rest" rate offset and store it in a variable. Subtract this variable from the rate returned by the sensor to get the actual rate. Integrate the rate over time to calculate the angle. (I haven't actually attempted this myself, but this is how you use, for example, the HiTechnic Gyro sensor since it does not provide an angle).

# Answer
> 5 votes
My team put their software fix in a loop with a small wait that cycles until the d/s = 0, then reset it to 0. Here's a simplified version:

It works like a charm. We don't mess with the hardware reset anymore. Combined with a heading variable, a turn my block, and a few drive my blocks they can program a maze run in minutes.

FWIW: They output their angle and rate to the display so they can monitor it even when not connected to a computer. They're working on checking the number of loops and total time it takes to optimize. Your team may need to play with the wait time a bit to get the best results.

# Answer
> 4 votes
The Gyro is a tricky sensor to use, but at yesterday's FLL competition in Elk River, at least 5 teams had worked out the issues to their satisfaction. I'm revealing their answers here. It is unfair to those teams, since their research does represent a significant advantage over other teams. That said, none of their solutions were complete. Each team had some part of the answer, but none had everything.

One team, not one of the 5, had given up on using the gyro in the belief that it could not be place close to the rechargeable battery pack because the gyro sensor would get too hot. I hadn't heard that before and have no idea if it has any basis in fact.

Almost all of the teams used the "Simple Gyro Fix" mentioned in the original question. They varied in whether they paused before, during, and after each step.

Two teams had tests to avoid leaving home base with a "drifting" gyro. One waited 10 seconds to see if the drift was still less than 2 degrees. Another ran the robot through a routine that cause the robot to twitch if it was drifting. No twitching meant it was ok.

A different set of two teams added a double reset of the gyro. This reset being the reset of the Gyro angle to 0. One of those teams said they had followed the advice of some site on the internet. That team also added a 1 second wait before and after the double reset. The first to "still" the robot; the second to ensure the zeroing of the gyro angle had been taken.

One team had a set of MyBlocks that turned based on either the rotation sensors or the gyro sensor. It allowed them to retreat from using the gyro sensor if they needed to. They had gone to the trouble because of the bad reputation of the Gyro sensor. In front of the judges, they used the gyro. It worked. Clearly, they had worried a lot and then figured out how to use it.

The teams differed in how they turned. Some pivoted, some spinned, and some accepted any motion.

One team used the gyro to go straight, sort of a proportional line follower with a gyro sensor instead of light sensor. They did not use it for turns.

None of the teams did the work of recording the drifting episodes to a file. None of the teams displayed a warning as a sound, a blinking light, or a message on the LCD panel before the robot left the home base. None of the teams switch automagically to the rotation sensors when the gyro is known to be drifting.

None of the teams used #2 of the accepted answer.

# Answer
> 2 votes
The most reliable way I've found to quickly reset the gyro is simply unplug it & plug it into a different input port, then unplug it & plug it back into it's port. Just unplugging & plugging it into the same port doesn't always work for me.

My software always has a 1 sec delay as the first step, and then software reset of the gyro. This is so after pressing the button on the brick to run the program I have a sec to remove my hand & the bot settles perfectly still, then the gyro resets itself to zero before any motors start to run.

Just this last weekend I started using the gyro to run perfectly forward & it works like a charm, but I haven't experimented how long until it's off by a degree, etc.

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Tags: programming, ev3-g, gyro
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# Question
Title: Mindstorms program - myblocks that work fine when run individually but when executed as part of a larger program, break
We have a line following myblock, which follows the line perfectly if it runs alone. However, if we include it as a block as part of a larger program, it goes haywire when it gets to that step and can't follow the line that it's on. If we run our program step by step, it completes each task successfully. Has anyone encountered this issue, and if so, any ideas how we can fix the problem?

# Answer
We've figured out what the issue was - in the line follower we had issues with a loop breaking out consistently, so had changed it to a large motor block doing x number of cycles. when it was run individually, it worked fine as the number of cycles started from 0. When it was part of the larger code, it had already run that many cycles, so it immediately quit out of the line follower.
> 1 votes

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Tags: ev3, mindstorms
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