<p>The XL motor runs at approximately 220 RPM.  Therefore, the following gearbox from the <a href="https://www.clear.rice.edu/elec201/Book/legos.html" rel="nofollow noreferrer">ELEC 201 class LEGO Design module from Rice</a> should be sufficient:</p>

<p><img src="https://i.sstatic.net/Ud1fF.gif" alt="LEGO 243:1 Gearbox"></p>

CC BY-SA 3.0
2014-10-21T19:00:04.110Z
2014-10-21T19:00:04.110Z
Nick2253
<p>You can use a worm gear for a compact, high ratio gearbox. By putting a worm gear on the motor shaft and using it to drive a 24 tooth gear you can achieve a 24:1 reduction.</p>

<p><img src="https://i.sstatic.net/YlsSN.jpg" alt="For example"></p>

<p>For high torque applications you could use multiple parallel axles held together by gears or wheel hubs.</p>

CC BY-SA 3.0
2014-10-22T18:18:32.073Z
Sadly, a 24:1 doesn't resolve my problem. Maybe i can add some other gear using worm gear as the input.
Imlach
CC BY-SA 3.0
2014-10-22T18:43:27.920Z
Then by using two of these assemblies you can achieve 576:1 reduction. Or if that is too much, you can get another gear either before or after this setup for an additional 2:1 or 3:1 reduction.
zovits
CC BY-SA 3.0
2014-10-22T12:11:53.063Z
2014-10-22T14:00:15.637Z
2014-10-22T14:00:15.637Z
zovits
<p>I'm looking for the best way to gear down a Power Function XL.</p>

<p>I need to achieve a very slow output RPM (less than 1-2 RPM). I've tried a 625:1 gear (trough 40:8 gear). Can someone link to a well done gearbox like that? Moreover, how I can make an axle more resistant at high torque (I've tried with brick round 2x2).</p>

CC BY-SA 3.0
2014-10-21T18:50:13.943Z
Do you mean less than 1-2 RPM?  As written, you're indicating greater than 1-2 RPM.
Nick2253
CC BY-SA 3.0
2014-10-21T19:10:11.833Z
Yeah, I mean <1-2RPM (or around).
Imlach
<building><power-functions><gears>
Gearing down a PF XL
Imlach
# Gearing down a PF XL

(Asked by: username_0 on 2014-10-21)

I'm looking for the best way to gear down a Power Function XL.

I need to achieve a very slow output RPM (less than 1-2 RPM). I've tried a 625:1 gear (trough 40:8 gear). Can someone link to a well done gearbox like that? Moreover, how I can make an axle more resistant at high torque (I've tried with brick round 2x2).

**Tags:** building, power-functions, gears

> **Comments:**
> **username_1**: Do you mean less than 1-2 RPM?  As written, you're indicating greater than 1-2 RPM.  
> **username_0**: Yeah, I mean <1-2RPM (or around).  

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## 2 answers

### Answer by username_1 on 2014-10-21. Score: 4

The XL motor runs at approximately 220 RPM. Therefore, the following gearbox from the [ELEC 201 class LEGO Design module from Rice](https://www.clear.rice.edu/elec201/Book/legos.html) should be sufficient:

![LEGO 243:1 Gearbox](https://i.sstatic.net/Ud1fF.gif)


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### Answer by username_2 on 2014-10-22. Score: 2

You can use a worm gear for a compact, high ratio gearbox. By putting a worm gear on the motor shaft and using it to drive a 24 tooth gear you can achieve a 24:1 reduction.

![For example](https://i.sstatic.net/YlsSN.jpg)

For high torque applications you could use multiple parallel axles held together by gears or wheel hubs.

> **Comments:**
> **username_0**: Sadly, a 24:1 doesn't resolve my problem. Maybe i can add some other gear using worm gear as the input.  
> **username_2**: Then by using two of these assemblies you can achieve 576:1 reduction. Or if that is too much, you can get another gear either before or after this setup for an additional 2:1 or 3:1 reduction.  

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