<p>It sounds like you need a stronger differential.</p>

<p>Might I suggest <a href="http://www.brickshelf.com/cgi-bin/gallery.cgi?f=508104" rel="nofollow noreferrer">this design by Nazgarot</a>:</p>

<p><a href="https://i.sstatic.net/mUAFz.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/mUAFz.png" alt="enter image description here"></a></p>

<p>If you make two, you can build a big and sturdy subtractor like this (probably customizing the gear ratios to your requirements, the right gearing could also remove the need for a PF switch):</p>

<p><a href="https://i.sstatic.net/iRdt1.jpg" rel="nofollow noreferrer"><img src="https://i.sstatic.net/iRdt1.jpg" alt="enter image description here"></a></p>

<p><a href="https://i.sstatic.net/dLFHY.jpg" rel="nofollow noreferrer"><img src="https://i.sstatic.net/dLFHY.jpg" alt="enter image description here"></a></p>

<p><a href="https://i.sstatic.net/c66Ls.jpg" rel="nofollow noreferrer"><img src="https://i.sstatic.net/c66Ls.jpg" alt="enter image description here"></a></p>

<p>Here's a video of it in action:</p>

<p><a href="https://www.youtube.com/watch?v=qndQNgcSKgE" rel="nofollow noreferrer"><img src="https://i.sstatic.net/DNHEH.jpg" alt="enter image description here"></a></p>

CC BY-SA 4.0
2018-12-13T02:58:31.710Z
Very nice answer. You deserve to get the six-sided hat for this. :)
jncraton
CC BY-SA 4.0
2018-12-13T15:06:46.663Z
Excellent. I've come back to this question like 4 times hoping someone had finally figured out a decent answer.
MindS1
CC BY-SA 4.0
2018-12-13T01:40:28.237Z
2018-12-20T19:04:17.947Z
2018-12-20T19:04:17.947Z
Alexander O'Mara
<p>I would like to use a subtractor in my next RC LEGO tank, as it enables the vehicle to turn on the move, as opposed to stopping and then turning.</p>

<p>Unfortunately, the subtractors I have tested so far cannot withstand the torque of heavy vehicles, which either causes the subtractor to break apart, or the differentials/gears to grind.</p>

<p>Does anyone know any subtractor designs which are able to deal with high tension/torque/stress levels so that enormous vehicles can still use them? 3kg-5kg tolerance would be ideal.</p>

<technic><gears><mechanical>
High Torque Subtractors
Nick Barham
# High Torque Subtractors

(Asked by: username_0 on 2018-04-13)

I would like to use a subtractor in my next RC LEGO tank, as it enables the vehicle to turn on the move, as opposed to stopping and then turning.

Unfortunately, the subtractors I have tested so far cannot withstand the torque of heavy vehicles, which either causes the subtractor to break apart, or the differentials/gears to grind.

Does anyone know any subtractor designs which are able to deal with high tension/torque/stress levels so that enormous vehicles can still use them? 3kg-5kg tolerance would be ideal.

**Tags:** technic, gears, mechanical


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## 1 answers

### Answer by username_1 on 2018-12-13. Score: 6

It sounds like you need a stronger differential.

Might I suggest [this design by Nazgarot](http://www.brickshelf.com/cgi-bin/gallery.cgi?f=508104):

[![enter image description here](https://i.sstatic.net/mUAFz.png)](https://i.sstatic.net/mUAFz.png)

If you make two, you can build a big and sturdy subtractor like this (probably customizing the gear ratios to your requirements, the right gearing could also remove the need for a PF switch):

[![enter image description here](https://i.sstatic.net/iRdt1.jpg)](https://i.sstatic.net/iRdt1.jpg)

[![enter image description here](https://i.sstatic.net/dLFHY.jpg)](https://i.sstatic.net/dLFHY.jpg)

[![enter image description here](https://i.sstatic.net/c66Ls.jpg)](https://i.sstatic.net/c66Ls.jpg)

Here's a video of it in action:

[![enter image description here](https://i.sstatic.net/DNHEH.jpg)](https://www.youtube.com/watch?v=qndQNgcSKgE)

> **Comments:**
> **username_2**: Very nice answer. You deserve to get the six-sided hat for this. :)  
> **username_3**: Excellent. I've come back to this question like 4 times hoping someone had finally figured out a decent answer.  

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