<p>The LEGO Digital Designer software does not have the ability to simulate the interaction of gears.</p>

<p>There is a similar software program called <a href="http://sr3dbuilder.altervista.org/" rel="nofollow">SR 3D Builder</a> that does have this capability.</p>

CC BY-SA 3.0
2016-10-09T19:16:17.720Z
Thank you for the suggestion, I'll have to check out that program.
Jedi_Maseter_Sam
CC BY-SA 3.0
2018-02-07T03:15:05.777Z
None of the links there work: download, user manuals, forum. Is there any other location to download it from?
David
CC BY-SA 4.0
2019-01-13T21:33:00.520Z
The author of SR 3D Builder passed away in 2014, so the software and website has not been maintained since then. https://forums.ldraw.org/thread-15315-post-15315.html#pid15315
David Lechner
CC BY-SA 4.0
2019-04-18T15:05:51.030Z
@David You can download it from here http://www.download82.com/get/download/windows/sr-3d-builder/
musicinmusic
CC BY-SA 3.0
2016-10-08T17:01:56.940Z
2016-10-08T17:01:56.940Z
David Lechner
<p>LDD is a design solution for static models. It is not a functional simulation tool. The gears turn with the crank handle if they are associated to the same group, but that is only because the gears, the axle and the handle share the same rotation point. The toothed bar does not share that same rotation point (and is likely not part of your "group" that contains the handle, axle and gears) and hence does not turn. If you made it part of the group, it would rotate around the center of the axle, which is not the effect you are looking for.</p>

CC BY-SA 3.0
2016-10-07T19:56:40.367Z
I have seen some videos where people get systems of gears to work, but that does not work when I try it either.  Is there specific mode that I need to use to get something like that to work
Jedi_Maseter_Sam
CC BY-SA 3.0
2016-10-07T19:47:33.287Z
2016-10-07T19:47:33.287Z
Phil B.
<p>I just started using LDD, and I have been trying out a few things that I couldn't do with the limitations of my Lego collection.  One thing that has me caught up is that I can't seem to get the technic gears to interact with the Toothed Bar piece.  I know this is possible in real life, but I was wondering if it is possible to do on the computer.</p>

<p>In the project I have, I want the lever to be turned and the platform attached to the Toothed Bars to go up or down.  Right now, only the gears on the axle spin when rotated.</p>

<p><a href="https://i.sstatic.net/KooJl.png" rel="noreferrer"><img src="https://i.sstatic.net/KooJl.png" alt="example project"></a></p>

<technic><gears><ldd>
Lego Digital Designer: Having Gears Interact with Toothed Bar
Jedi_Maseter_Sam
# Lego Digital Designer: Having Gears Interact with Toothed Bar

(Asked by: username_0 on 2016-10-07)

I just started using LDD, and I have been trying out a few things that I couldn't do with the limitations of my Lego collection. One thing that has me caught up is that I can't seem to get the technic gears to interact with the Toothed Bar piece. I know this is possible in real life, but I was wondering if it is possible to do on the computer.

In the project I have, I want the lever to be turned and the platform attached to the Toothed Bars to go up or down. Right now, only the gears on the axle spin when rotated.

[![example project](https://i.sstatic.net/KooJl.png)](https://i.sstatic.net/KooJl.png)

**Tags:** technic, gears, ldd


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## 2 answers

### Answer by username_1 on 2016-10-08. Score: 4 | Accepted answer

The LEGO Digital Designer software does not have the ability to simulate the interaction of gears.

There is a similar software program called [SR 3D Builder](http://sr3dbuilder.altervista.org/) that does have this capability.

> **Comments:**
> **username_0**: Thank you for the suggestion, I'll have to check out that program.  
> **username_2**: None of the links there work: download, user manuals, forum. Is there any other location to download it from?  
> **username_1**: The author of SR 3D Builder passed away in 2014, so the software and website has not been maintained since then. https://forums.ldraw.org/thread-15315-post-15315.html#pid15315  
> **username_3**: @username_2 You can download it from here http://www.download82.com/get/download/windows/sr-3d-builder/  

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### Answer by username_4 on 2016-10-07. Score: 4

LDD is a design solution for static models. It is not a functional simulation tool. The gears turn with the crank handle if they are associated to the same group, but that is only because the gears, the axle and the handle share the same rotation point. The toothed bar does not share that same rotation point (and is likely not part of your "group" that contains the handle, axle and gears) and hence does not turn. If you made it part of the group, it would rotate around the center of the axle, which is not the effect you are looking for.

> **Comments:**
> **username_0**: I have seen some videos where people get systems of gears to work, but that does not work when I try it either.  Is there specific mode that I need to use to get something like that to work  

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