<h3>Stepper motors</h3>
<p>For equivalence, 4.8 kg⋅cm is 0.471 N⋅m or 47 N⋅cm.</p>
<p>Looking at the RepRapWiki - <a href="https://reprap.org/wiki/NEMA_17_Stepper_motor" rel="nofollow noreferrer">Nema17</a>, the most common steppers are:</p>
<ul>
<li>Kysan 1124090/42BYGH4803 (54.0 N⋅cm),</li>
<li>Rattm 17HS8401 (52 N⋅cm), and</li>
<li>Wantai 42BYGHW609 (<a href="https://www.my-home-fab.de/en/documentations/technical-descriptions/technical-data-for-nema-17-42byghw609" rel="nofollow noreferrer">39.2 N⋅cm</a>).</li>
</ul>
<p>The Kossel that you refer to is of a similar size to the Kossel XL. Again looking at the RepRapWiki - <a href="https://reprap.org/wiki/Kossel" rel="nofollow noreferrer">Kossel</a>, the recommended stepper is the <a href="https://ultimachine.com/products/kysan-1124090-nema-17-stepper-motor" rel="nofollow noreferrer">Kysan 1124090 Nema 17 Stepper Motor</a> which has a Holding Torque of 5.5 kg⋅cm.</p>
<p>So, without knowing the exact make and model of your stepper motors and assuming that the specifications for your stepper motors given in the <a href="https://reprapguru.com/collections/3d-printers/products/reprap-guru-diy-prusa-i3-v2-3d-printer-kit" rel="nofollow noreferrer">Prusa clone</a> are correct, your steppers are not as strong as those recommended (apart from the Wantai). However, the recommended steppers may be over-engineered and provide [much?] more torque than is strictly necessary. After all, the holding torque of your steppers isn't <em>that much</em> below the recommended values.</p>
<p>If I were you I'd build the Kossel using your steppers and it might, in all likely hood, work out fine. FWIW, I have used the Rattm 17HS8401 in my Kossel Mini and Kossel XL. I got them on eBay and were quite reasonably priced.</p>
<p>You should probably read this article, RepRapWiki - <a href="https://reprap.org/wiki/Choosing_stepper_for_a_delta" rel="nofollow noreferrer">Choosing stepper for a delta</a>. Whilst no concrete values for holding torque are given, this is interesting:</p>
<blockquote>
<h3>A good practical setup</h3>
<p>The Fisher, a small delta printer was designed by late RRP company. As for all their printers, they were using small and compact steppers with a torque of 2.2 kg.cm. This is lower than most repraps but is sufficient if there is no mechanical problem (friction).</p>
<p>These small motors have a low nominal static torque, but they also have a low inductance (2.5 mH), while due to their small size, the nominal current remains reasonable (1.2A).</p>
</blockquote>
<p>as is</p>
<blockquote>
<h3>High inductance motors</h3>
<p>You find on the market steppers sold for 3D printers, with a torque ranging from 2.6 to 4.4 kg.cm and a current of 0.4 A. This low current appeal builders as it make the electronic driver heating much less.</p>
<p>However, it came at a cost, which is a very high inductance which varies from 30 to 35 mH. That means these motors are totally incapable of any speed. They are unusable for a delta and a bad choice for another printer. As an example, a 4.4 kg.cm motor wired for this low current, while having a static torque twice the Fisher motors, simply cannot reach the maximum speed used by the Fisher, effectively having a near zero torque over a given speed. Same motors with a winding giving a nominal current of 1.5 to 2 A will be more usable.</p>
</blockquote>
<h3>Controller</h3>
<p>Also, yes, RAMPS is fine for the Kossel, although the firmware calibration is obviously different, as it is a delta and not cartesian printer. For calibration, refer to <a href="https://3dprinting.stackexchange.com/questions/6798/how-do-you-calibrate-a-delta-robot-3d-printer">How do you calibrate a delta robot 3D printer?</a>.</p>
<p>Although, as Scott Lahteine <a href="https://www.youtube.com/watch?v=QJx75PWE6dQ&amp;t=84" rel="nofollow noreferrer">states early on</a> in this video, <a href="https://www.youtube.com/watch?v=QJx75PWE6dQ" rel="nofollow noreferrer">How it's Made: The Marlin Firmware!</a>, using an 8-bit controller for delta printers is pushing their capabilities somewhat.</p>
<h3>Extruder</h3>
<p>I'm not familiar with the Flex3Drive, but it certainly looks interesting. I have used the <a href="http://www.phidgets.com/products.php?product_id=3325" rel="nofollow noreferrer">3325_0</a>, this NEMA-17 motor has an integrated Planetary gearbox with a 52/11:1 ratio. It generates 16.2 kg⋅cm of torque at 1.68 A. I wrote a short blog about it here, <a href="https://gr33nonline.wordpress.com/2017/05/09/the-extraordinary-extruder/" rel="nofollow noreferrer">The extraordinary extruder</a>.</p>
<h3>Building Tips</h3>
<p>Also, if you are planning on building a Delta/Kossel, then I'd seriously recommend watching the series of videos on YouTube from <a href="https://www.youtube.com/channel/UCIB6RIygkQMvwiRskL22p6w" rel="nofollow noreferrer">BuildA3DPrinter.eu</a> as they are extremely informative and helped me a lot, <a href="https://www.youtube.com/watch?v=AXy1OFMEUTg&amp;list=PLvkxDPeJpn0WRw8BBw0L_j8BxFcuTKI8N" rel="nofollow noreferrer">Build manual Kossel XL &amp; Kossel Mini</a>. I just checked their website to try to see which make and model of steppers they use, in order to get an idea of the holding torque, but they seem to have stopped trading. However, their <a href="http://builda3dprinter.eu/product/nema-17-stepper-motor/" rel="nofollow noreferrer">stepper motor page</a> states the following:</p>
<blockquote>
<p>The standard motor for most 3D printers including ours, the 42byghw811
from Wantai Motors.</p>
<p>Holding torque is 4.8 kg⋅cm or 47.1 N⋅cm. Shaft diameter is 5 mm and
stepping angle is 1.8 degrees.</p>
</blockquote>
<p>So, to sum up, your steppers <em>should</em> be fine.</p>

CC BY-SA 4.0
2019-05-04T06:46:21.827Z
@TomvanderZanden - lol, I had removed all of the dots, but you're correct in reinstating them, I've just [checked](https://en.m.wikipedia.org/wiki/Newton_metre). Thanks :-)
Greenonline
CC BY-SA 4.0
2019-05-04T08:48:07.030Z
I was mostly annoyed at the kg/cm notation being used in some places, because that's plain wrong :-)
Tom van der Zanden
CC BY-SA 4.0
2019-05-12T12:34:58.337Z
Have you thoughts about adding a small gear train in a 3:2 reduction stage to gain about 50% more torque and steps/mm on the cost of increased backlash and complexity?
Trish
CC BY-SA 4.0
2019-05-13T02:40:50.223Z
@Trish - wouldn't that reduce the speed though? I'm not really sure whether additional torque is necessary. The issue is, I guess, that I haven't seen any concrete figures, from empirical testing for the **absolute minimum torque** required for a *particular* delta printer, of a *particular dimension*. It would be most interesting to see if anyone has actually done such tests.
Greenonline
CC BY-SA 4.0
2019-05-13T13:03:17.610Z
the speed reduction should be mitigated by using more steps/mm in the firmware, but one might run into the physical limitations of the motor. The idea of using some gearbox only came up from the thought *if torque might be too small, how to get the torque up?*
Trish
CC BY-SA 4.0
2019-05-03T22:24:04.607Z
2019-05-11T15:30:08.980Z
2020-06-18T08:29:41.667Z
Greenonline
<p>I have a generic <a href="https://reprapguru.com/collections/3d-printers/products/reprap-guru-diy-prusa-i3-v2-3d-printer-kit" rel="nofollow noreferrer">Prusa clone</a> that I'm not using (my primary issue with it is the lack of rigidity in the frame housing as built). Will the motors (<a href="https://protosupplies.com/product/stepper-motor-nema-17-1-2a-ks42sth40-1204a/" rel="nofollow noreferrer">ks42sth40-1204a</a>) and controller that come with it be good for a large-ish Kossel? Something no smaller than 200x200, preferably closer to 300x300? How do I reason about this?</p>

<p>Also - I know the Duet board seems to be recommended for Deltas, but can I use the RAMPS board that I already have here?</p>

<p>I don't have a design finalized, but have been looking at this Kossel, <a href="https://www.norwegiancreations.com/2017/01/building-a-large-kossel-delta-printer-pt-1-parts-and-planning/" rel="nofollow noreferrer">Building a Large Kossel Delta Printer – pt. 1: Parts and Planning</a>, which uses a <a href="https://flex3drive.com/flex3drive/" rel="nofollow noreferrer">Flex3Drive effector</a>.</p>

CC BY-SA 4.0
2019-05-03T17:09:45.040Z
what design are you using? What is the weight of the print head including arms and belts?
Trish
CC BY-SA 4.0
2019-05-03T17:49:37.233Z
@Trish added design link
kolosy
CC BY-SA 4.0
2019-05-03T22:04:48.827Z
What is the make and model of your stepper motors, is there a sticker on them anywhere? Or is the only information that you have about them from the `Prusa clone` link that you provided?
Greenonline
CC BY-SA 4.0
2019-05-04T06:41:51.787Z
Please ask only one question per question. This question is too broad, as the question about the controller is entirely unrelated to the question about the motors.
Tom van der Zanden
CC BY-SA 4.0
2019-05-05T17:57:30.427Z
@TomvanderZanden given the excellent answer below, I'll keep this together, but will adjust the title to reflect the overall question - can I repurpose most of these prusa clone parts for a delta.
kolosy
CC BY-SA 4.0
2019-05-05T18:25:34.610Z
kolosy, did you look to see if your steppers have any stickers on them, indicating make and model?
Greenonline
CC BY-SA 4.0
2019-05-05T23:41:43.897Z
@Greenonline I did - just added it to the q.
kolosy
CC BY-SA 4.0
2019-05-06T07:42:13.507Z
Hmmm, it is interesting that the holding torque on the stepper specification (4.0)  differs quite significantly by ~20% from that on the printer's link (4.8). Although it is still higher than that of the Wantai below.
Greenonline
<prusa-i3><diy-3d-printer><printer-building><delta>
Can I repurpose most of the components of this Prusa clone for a Delta?
kolosy
# Can I repurpose most of the components of this Prusa clone for a Delta?

(Asked by: username_0 on 2019-05-03)

I have a generic [Prusa clone](https://reprapguru.com/collections/3d-printers/products/reprap-guru-diy-prusa-i3-v2-3d-printer-kit) that I'm not using (my primary issue with it is the lack of rigidity in the frame housing as built). Will the motors ([ks42sth40-1204a](https://protosupplies.com/product/stepper-motor-nema-17-1-2a-ks42sth40-1204a/)) and controller that come with it be good for a large-ish Kossel? Something no smaller than 200x200, preferably closer to 300x300? How do I reason about this?

Also - I know the Duet board seems to be recommended for Deltas, but can I use the RAMPS board that I already have here?

I don't have a design finalized, but have been looking at this Kossel, [Building a Large Kossel Delta Printer – pt. 1: Parts and Planning](https://www.norwegiancreations.com/2017/01/building-a-large-kossel-delta-printer-pt-1-parts-and-planning/), which uses a [Flex3Drive effector](https://flex3drive.com/flex3drive/).

**Tags:** prusa-i3, diy-3d-printer, printer-building, delta

> **Comments:**
> **username_1**: what design are you using? What is the weight of the print head including arms and belts?  
> **username_0**: @username_1 added design link  
> **username_2**: What is the make and model of your stepper motors, is there a sticker on them anywhere? Or is the only information that you have about them from the `Prusa clone` link that you provided?  
> **username_3**: Please ask only one question per question. This question is too broad, as the question about the controller is entirely unrelated to the question about the motors.  
> **username_0**: @username_3 given the excellent answer below, I'll keep this together, but will adjust the title to reflect the overall question - can I repurpose most of these prusa clone parts for a delta.  
> **username_2**: username_0, did you look to see if your steppers have any stickers on them, indicating make and model?  
> **username_0**: @username_2 I did - just added it to the q.  
> **username_2**: Hmmm, it is interesting that the holding torque on the stepper specification (4.0)  differs quite significantly by ~20% from that on the printer's link (4.8). Although it is still higher than that of the Wantai below.  

---

## 1 answers

### Answer by username_2 on 2019-05-03. Score: 3 | Accepted answer

### Stepper motors

For equivalence, 4.8 kg⋅cm is 0.471 N⋅m or 47 N⋅cm.

Looking at the RepRapWiki - [Nema17](https://reprap.org/wiki/NEMA_17_Stepper_motor), the most common steppers are:

* Kysan 1124090/42BYGH4803 (54.0 N⋅cm),
* Rattm 17HS8401 (52 N⋅cm), and
* Wantai 42BYGHW609 ([39.2 N⋅cm](https://www.my-home-fab.de/en/documentations/technical-descriptions/technical-data-for-nema-17-42byghw609)).

The Kossel that you refer to is of a similar size to the Kossel XL. Again looking at the RepRapWiki - [Kossel](https://reprap.org/wiki/Kossel), the recommended stepper is the [Kysan 1124090 Nema 17 Stepper Motor](https://ultimachine.com/products/kysan-1124090-nema-17-stepper-motor) which has a Holding Torque of 5.5 kg⋅cm.

So, without knowing the exact make and model of your stepper motors and assuming that the specifications for your stepper motors given in the [Prusa clone](https://reprapguru.com/collections/3d-printers/products/reprap-guru-diy-prusa-i3-v2-3d-printer-kit) are correct, your steppers are not as strong as those recommended (apart from the Wantai). However, the recommended steppers may be over-engineered and provide [much?] more torque than is strictly necessary. After all, the holding torque of your steppers isn't *that much* below the recommended values.

If I were you I'd build the Kossel using your steppers and it might, in all likely hood, work out fine. FWIW, I have used the Rattm 17HS8401 in my Kossel Mini and Kossel XL. I got them on eBay and were quite reasonably priced.

You should probably read this article, RepRapWiki - [Choosing stepper for a delta](https://reprap.org/wiki/Choosing_stepper_for_a_delta). Whilst no concrete values for holding torque are given, this is interesting:

> ### A good practical setup
>
> The Fisher, a small delta printer was designed by late RRP company. As for all their printers, they were using small and compact steppers with a torque of 2.2 kg.cm. This is lower than most repraps but is sufficient if there is no mechanical problem (friction).
>
> These small motors have a low nominal static torque, but they also have a low inductance (2.5 mH), while due to their small size, the nominal current remains reasonable (1.2A).

as is

> ### High inductance motors
>
> You find on the market steppers sold for 3D printers, with a torque ranging from 2.6 to 4.4 kg.cm and a current of 0.4 A. This low current appeal builders as it make the electronic driver heating much less.
>
> However, it came at a cost, which is a very high inductance which varies from 30 to 35 mH. That means these motors are totally incapable of any speed. They are unusable for a delta and a bad choice for another printer. As an example, a 4.4 kg.cm motor wired for this low current, while having a static torque twice the Fisher motors, simply cannot reach the maximum speed used by the Fisher, effectively having a near zero torque over a given speed. Same motors with a winding giving a nominal current of 1.5 to 2 A will be more usable.

### Controller

Also, yes, RAMPS is fine for the Kossel, although the firmware calibration is obviously different, as it is a delta and not cartesian printer. For calibration, refer to [How do you calibrate a delta robot 3D printer?](https://3dprinting.stackexchange.com/questions/6798/how-do-you-calibrate-a-delta-robot-3d-printer).

Although, as Scott Lahteine [states early on](https://www.youtube.com/watch?v=QJx75PWE6dQ&t=84) in this video, [How it's Made: The Marlin Firmware!](https://www.youtube.com/watch?v=QJx75PWE6dQ), using an 8-bit controller for delta printers is pushing their capabilities somewhat.

### Extruder

I'm not familiar with the Flex3Drive, but it certainly looks interesting. I have used the [3325\_0](http://www.phidgets.com/products.php?product_id=3325), this NEMA-17 motor has an integrated Planetary gearbox with a 52/11:1 ratio. It generates 16.2 kg⋅cm of torque at 1.68 A. I wrote a short blog about it here, [The extraordinary extruder](https://gr33nonline.wordpress.com/2017/05/09/the-extraordinary-extruder/).

### Building Tips

Also, if you are planning on building a Delta/Kossel, then I'd seriously recommend watching the series of videos on YouTube from [BuildA3DPrinter.eu](https://www.youtube.com/channel/UCIB6RIygkQMvwiRskL22p6w) as they are extremely informative and helped me a lot, [Build manual Kossel XL & Kossel Mini](https://www.youtube.com/watch?v=AXy1OFMEUTg&list=PLvkxDPeJpn0WRw8BBw0L_j8BxFcuTKI8N). I just checked their website to try to see which make and model of steppers they use, in order to get an idea of the holding torque, but they seem to have stopped trading. However, their [stepper motor page](http://builda3dprinter.eu/product/nema-17-stepper-motor/) states the following:

> The standard motor for most 3D printers including ours, the 42byghw811
> from Wantai Motors.
>
> Holding torque is 4.8 kg⋅cm or 47.1 N⋅cm. Shaft diameter is 5 mm and
> stepping angle is 1.8 degrees.

So, to sum up, your steppers *should* be fine.

> **Comments:**
> **username_2**: @username_3 - lol, I had removed all of the dots, but you're correct in reinstating them, I've just [checked](https://en.m.wikipedia.org/wiki/Newton_metre). Thanks :-)  
> **username_3**: I was mostly annoyed at the kg/cm notation being used in some places, because that's plain wrong :-)  
> **username_1**: Have you thoughts about adding a small gear train in a 3:2 reduction stage to gain about 50% more torque and steps/mm on the cost of increased backlash and complexity?  
> **username_2**: @username_1 - wouldn't that reduce the speed though? I'm not really sure whether additional torque is necessary. The issue is, I guess, that I haven't seen any concrete figures, from empirical testing for the **absolute minimum torque** required for a *particular* delta printer, of a *particular dimension*. It would be most interesting to see if anyone has actually done such tests.  
> **username_1**: the speed reduction should be mitigated by using more steps/mm in the firmware, but one might run into the physical limitations of the motor. The idea of using some gearbox only came up from the thought *if torque might be too small, how to get the torque up?*  

---

