<p>Your parts are not in the Prusa Mendel i2 as found <a href="http://www.reprap.org/wiki/Prusa_Mendel_(iteration_2)" rel="nofollow noreferrer">here</a> or <a href="https://github.com/josefprusa/PrusaMendel" rel="nofollow noreferrer">here</a>.</p>

<p>Also note, quote:</p>

<blockquote>
  <p>Parts included in Github repository have the wrong dimensions for the
  nut traps! Download the correct version from <a href="http://www.thingiverse.com/thing:8252" rel="nofollow noreferrer">[Thingiverse Greg's
  Hinged Accesible Extruder]</a></p>
</blockquote>

<p>Are you sure you have the correct parts for the original Prusa Mendel i2? Maybe you have a different version? The original extruder mount uses an M8 hobbed bolt, not an MK8 hobbed extruder gear. The first is 8 mm in diameter, the latter is 9 mm in diameter.</p>

<hr>

<p><strong>Edit:</strong>
After you updated your post to hint to the correct printer, it appears that my answer still holds. You did use the incorrect extruder gear. The 9 mm gear doesn't fit in the extruder part as it requires an 8 mm diameter extruder gear.</p>

<p>It might be difficult to find a 8 mm hobbed gear with a 3 mm shaft diameter, they are usually 5 mm (as in the stepper shaft diameter) or 8 mm (as in the diameter of 8 mm bolts that are frequently used for extruder setups). You could redesign the part (load STL in a 3D CAD program and make the changes). By the way, PLA should not shrink so much. As can be seen in the photo's, it looks like your current printer does not print very accurately, that may also contribute.</p>

CC BY-SA 4.0
2018-06-20T18:09:39.223Z
Sorry for incorrect info. Actually the printer is not entirely Reprap Prusa Mendel but it is **AlfaMendel AM1** which is similar to Prusa Mendel I2. The link for its manual is [link](https://drive.google.com/open?id=1rcsy922SaEuJyy8FaSfNMyOS690cT-BJ). You may check page no. 126 of the manual for its extruder drive. Actually I didnot correctly read it, the printer requires a 8mm M3 hobbed drive, not the MK8 which I have. Buy the way, thank you for the answer :)
MSD
CC BY-SA 4.0
2018-06-20T18:10:20.800Z
Can I print a hobbed drive using PLA, instead of purchasing a metallic one ?
MSD
CC BY-SA 4.0
2018-06-20T18:18:37.180Z
@MSD No you cannot print that to use it functionally.
0scar
CC BY-SA 4.0
2018-06-20T18:25:52.447Z
OK :)

Also, I am not able to insert the PLA filament into the extruder drive (via the hole in the very first pic), I think it has shrinked. What should I use to drill it to make it proper or some other way to make it correct ?
MSD
CC BY-SA 4.0
2018-06-19T14:25:40.820Z
2018-06-20T18:42:33.740Z
2018-06-20T18:42:33.740Z
0scar
<p>I am building a <strong>AlfaMendel 3D printer</strong> <em>(<strong>edited</strong> : The original question named it to be Prusa Mendel I2)</em>. I printed the extruder drive <strong>using PLA material</strong> from the STL available in the package but I'm not able to insert the hobbed drive as well as the filament in it. The dimensions of hobbed drive is correct. </p>

<p>Is the problem related to shrinking of print material while printing the extruder drive or something else.</p>

<p>I have included few pics of the extruder drive and hobbed drive.</p>

<p><a href="https://i.sstatic.net/ZIhLs.jpg" rel="nofollow noreferrer" title="Filament hole in extruder drive"><img src="https://i.sstatic.net/ZIhLs.jpg" alt="Filament hole in extruder drive" title="Filament hole in extruder drive"></a></p>

<p><a href="https://i.sstatic.net/YbaYk.jpg" rel="nofollow noreferrer" title="Extruder drive"><img src="https://i.sstatic.net/YbaYk.jpg" alt="Extruder drive" title="Extruder drive"></a></p>

<p><a href="https://i.sstatic.net/kFbGF.jpg" rel="nofollow noreferrer" title="Close up of extruder drive"><img src="https://i.sstatic.net/kFbGF.jpg" alt="Close up of extruder drive" title="Close up of extruder drive"></a></p>

<p><a href="https://i.sstatic.net/VxIBH.jpg" rel="nofollow noreferrer" title="Hobbed Drive"><img src="https://i.sstatic.net/VxIBH.jpg" alt="Hobbed Drive" title="Hobbed Drive"></a></p>

<p>This image shows the maximum possible insertion of hobbed drive in the extruder drive.</p>

<p><a href="https://i.sstatic.net/HmgsF.jpg" rel="nofollow noreferrer" title="Trying to insert the hobbed drive in the extruder drive"><img src="https://i.sstatic.net/HmgsF.jpg" alt="Trying to insert the hobbed drive in the extruder drive" title="Trying to insert the hobbed drive in the extruder drive"></a></p>

CC BY-SA 4.0
2018-06-19T13:10:41.480Z
The MK7 and MK8 hobbed extruder gears have different diameters. One is 12 mm and the other is 9 mm respectively, so the question is what diameter is your hobbed gear?
0scar
CC BY-SA 4.0
2018-06-19T13:15:33.557Z
Its MK8 with 9mm diameter
MSD
CC BY-SA 4.0
2018-06-19T13:19:29.477Z
You need to add more information; e.g. what material you printed, a photo with the gear (tried to fit) in the printed part, measured dimensions, STL model dimensions.
0scar
CC BY-SA 4.0
2018-06-19T13:35:18.753Z
I have used PLA to print the part, as much I remember the measured diameter of the hole in extruder drive was 7.9 - 8 mm (actually I don't have a Vernier Calliper at present) and I added one more pic in the edited version
MSD
<prusa-i3><reprap>
Not able to insert hobbed drive and filament in the extruder drive
MSD
# Not able to insert hobbed drive and filament in the extruder drive

(Asked by: username_0 on 2018-06-19)

I am building a **AlfaMendel 3D printer** *(**edited** : The original question named it to be Prusa Mendel I2)*. I printed the extruder drive **using PLA material** from the STL available in the package but I'm not able to insert the hobbed drive as well as the filament in it. The dimensions of hobbed drive is correct.

Is the problem related to shrinking of print material while printing the extruder drive or something else.

I have included few pics of the extruder drive and hobbed drive.

[![Filament hole in extruder drive](https://i.sstatic.net/ZIhLs.jpg "Filament hole in extruder drive")](https://i.sstatic.net/ZIhLs.jpg "Filament hole in extruder drive")

[![Extruder drive](https://i.sstatic.net/YbaYk.jpg "Extruder drive")](https://i.sstatic.net/YbaYk.jpg "Extruder drive")

[![Close up of extruder drive](https://i.sstatic.net/kFbGF.jpg "Close up of extruder drive")](https://i.sstatic.net/kFbGF.jpg "Close up of extruder drive")

[![Hobbed Drive](https://i.sstatic.net/VxIBH.jpg "Hobbed Drive")](https://i.sstatic.net/VxIBH.jpg "Hobbed Drive")

This image shows the maximum possible insertion of hobbed drive in the extruder drive.

[![Trying to insert the hobbed drive in the extruder drive](https://i.sstatic.net/HmgsF.jpg "Trying to insert the hobbed drive in the extruder drive")](https://i.sstatic.net/HmgsF.jpg "Trying to insert the hobbed drive in the extruder drive")

**Tags:** prusa-i3, reprap
> **Comments:**
> **username_1**: The MK7 and MK8 hobbed extruder gears have different diameters. One is 12 mm and the other is 9 mm respectively, so the question is what diameter is your hobbed gear?  
> **username_0**: Its MK8 with 9mm diameter  
> **username_1**: You need to add more information; e.g. what material you printed, a photo with the gear (tried to fit) in the printed part, measured dimensions, STL model dimensions.  
> **username_0**: I have used PLA to print the part, as much I remember the measured diameter of the hole in extruder drive was 7.9 - 8 mm (actually I don't have a Vernier Calliper at present) and I added one more pic in the edited version  

---

## 1 answers

### Answer by username_1 on 2018-06-19. Score: 4 | Accepted answer

Your parts are not in the Prusa Mendel i2 as found [here](http://www.reprap.org/wiki/Prusa_Mendel_(iteration_2)) or [here](https://github.com/josefprusa/PrusaMendel).

Also note, quote:

> Parts included in Github repository have the wrong dimensions for the
> nut traps! Download the correct version from [[Thingiverse Greg's
> Hinged Accesible Extruder]](http://www.thingiverse.com/thing:8252)

Are you sure you have the correct parts for the original Prusa Mendel i2? Maybe you have a different version? The original extruder mount uses an M8 hobbed bolt, not an MK8 hobbed extruder gear. The first is 8 mm in diameter, the latter is 9 mm in diameter.

---

**Edit:**
After you updated your post to hint to the correct printer, it appears that my answer still holds. You did use the incorrect extruder gear. The 9 mm gear doesn't fit in the extruder part as it requires an 8 mm diameter extruder gear.

It might be difficult to find a 8 mm hobbed gear with a 3 mm shaft diameter, they are usually 5 mm (as in the stepper shaft diameter) or 8 mm (as in the diameter of 8 mm bolts that are frequently used for extruder setups). You could redesign the part (load STL in a 3D CAD program and make the changes). By the way, PLA should not shrink so much. As can be seen in the photo's, it looks like your current printer does not print very accurately, that may also contribute.

> **Comments:**
> **username_0**: Sorry for incorrect info. Actually the printer is not entirely Reprap Prusa Mendel but it is **AlfaMendel AM1** which is similar to Prusa Mendel I2. The link for its manual is [link](https://drive.google.com/open?id=1rcsy922SaEuJyy8FaSfNMyOS690cT-BJ). You may check page no. 126 of the manual for its extruder drive. Actually I didnot correctly read it, the printer requires a 8mm M3 hobbed drive, not the MK8 which I have. Buy the way, thank you for the answer :)  
> **username_0**: Can I print a hobbed drive using PLA, instead of purchasing a metallic one ?  
> **username_1**: @MSD No you cannot print that to use it functionally.  
> **username_0**: OK :)  Also, I am not able to insert the PLA filament into the extruder drive (via the hole in the very first pic), I think it has shrinked. What should I use to drill it to make it proper or some other way to make it correct ?  

---

