<p>I am attempting to build a 3D printer using the <a href="https://github.com/gregsaun/prusa_i3_b" rel="nofollow noreferrer">Bear Upgrade</a> for guidance.</p>

<p>In this moment, I am implementing the X-Axis. The X_end_idler consist in two parts, the idler and the belt tensioner, as you can see on the following pictures:</p>

<p><a href="https://i.sstatic.net/T9cVR.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/T9cVR.png" alt="X end idler and tensioner"></a> </p>

<p><a href="https://i.sstatic.net/xUirW.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/xUirW.png" alt="X end idler"></a></p>

<p><a href="https://i.sstatic.net/skBUV.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/skBUV.png" alt="Belt tensioner"></a></p>

<p>The belt tensioner is inserted inside the idler. It is attached to the idler with two screws on the back part of the idler.</p>

<p><a href="https://i.sstatic.net/0hlRX.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/0hlRX.png" alt="Back part of the idler"></a></p>

<p>The tensioner holds a 2GT Idler Pulley as per the image:
 <a href="https://i.sstatic.net/J2wJ7.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/J2wJ7.png" alt="X Idler with tensioner, pulley and belt "></a></p>

<p>So, here comes my question to anybody that has attempted to implement the Bear Upgrade:</p>

<p>How is the pulley attached to the tensioner? </p>

<p>The tensioner has a hole that crosses from side to side, but there is no space on the design where to fit a screw head nor a nut. I am a bit lost here and would like to know if there is a trick I can follow, before attempting to modify the design.</p>

<p>Here I attach the link to the pieces: <a href="https://github.com/gregsaun/bear_extruder_and_x_axis" rel="nofollow noreferrer">Bear_extruder_and_x_axis</a></p>

<hr>

<p>Bear_upgrade</p>

CC BY-SA 4.0
2020-01-30T20:29:11.413Z
What about a 3 mm axle/shaft, as it is enclosed it will not fall out. You could even cut the head of a screw and use the threads.
0scar
CC BY-SA 4.0
2020-01-30T22:06:21.803Z
Or maybe a roll/spring-pin?
Trish
<prusa-i3><diy-3d-printer>
Help needed implementing Bear Upgrade
Albaguti
# Help needed implementing Bear Upgrade

(Asked by: username_0 on 2020-01-30)

I am attempting to build a 3D printer using the [Bear Upgrade](https://github.com/gregsaun/prusa_i3_b) for guidance.

In this moment, I am implementing the X-Axis. The X\_end\_idler consist in two parts, the idler and the belt tensioner, as you can see on the following pictures:

[![X end idler and tensioner](https://i.sstatic.net/T9cVR.png)](https://i.sstatic.net/T9cVR.png)

[![X end idler](https://i.sstatic.net/xUirW.png)](https://i.sstatic.net/xUirW.png)

[![Belt tensioner](https://i.sstatic.net/skBUV.png)](https://i.sstatic.net/skBUV.png)

The belt tensioner is inserted inside the idler. It is attached to the idler with two screws on the back part of the idler.

[![Back part of the idler](https://i.sstatic.net/0hlRX.png)](https://i.sstatic.net/0hlRX.png)

The tensioner holds a 2GT Idler Pulley as per the image:
[![X Idler with tensioner, pulley and belt ](https://i.sstatic.net/J2wJ7.png)](https://i.sstatic.net/J2wJ7.png)

So, here comes my question to anybody that has attempted to implement the Bear Upgrade:

How is the pulley attached to the tensioner?

The tensioner has a hole that crosses from side to side, but there is no space on the design where to fit a screw head nor a nut. I am a bit lost here and would like to know if there is a trick I can follow, before attempting to modify the design.

Here I attach the link to the pieces: [Bear\_extruder\_and\_x\_axis](https://github.com/gregsaun/bear_extruder_and_x_axis)

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Bear\_upgrade

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

> **Comments:**
> **username_1**: What about a 3 mm axle/shaft, as it is enclosed it will not fall out. You could even cut the head of a screw and use the threads.  
> **username_2**: Or maybe a roll/spring-pin?  

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## 0 answers

