Why is the motor on the Jonaskuehling extruder rotated?

I’m wondering why the Jonaskuehling Greg’s Wade extruder used on all Lulzbot printers mounts the stepper motor at a 25 degree angle. Is there any technical reason to do so?

The reason I ask is twofold:

  • The one on my AO-100 is delaminating and I need to print a replacement
  • Because the motor is rotated, the X axis endstop is not adjusted as near the left side as it could or the motor would hit the leadscrew. This causes X home to start about 1/2 inch (13mm) from the side of the glass. In effect the print size is not 190mm wide but 185. I witnessed this first hand when printing tonight and the skirt printed past the glass bed at the far right. It would have needed that 5mm. :smiley: (the part was fine)

If I put the motor “straight” rather than slanted then I can salvage the 5mm I’m missing.

I also notice that the small gear and the large gear rotation axes are aligned horizontally. If I were to offset the small gear toward the bottom would there be any problem? I believe that’s what 1013 did with his TAZ dual extruder so I’m guessing it would not matter…

Any thoughts welcome. :slight_smile:

OK after some search I found the reason here: Accessible Wade’s Extruder by GregFrost

  1. The motor can be removed without removing the large gear. The three mounting screws can be accessed without removing the gear. 2 of them are clearly accessible and the other is accessible through a hole in the gear.

  2. The rotated motor mount means that the carriage attachment screw is accessible with the motor installed.

  3. The rotated motor mount also means that the clearance past the idler attachment captive nuts is a bit longer, so you have a bit more play tensioning the idler.

I’ll have to think if there’s a real benefit with #2 and #4, as for #5 I don’t think the jonaskuehling variant needs it anymore.

Still to answer is why all current extruders put the small and large gear axes inline.

screw accessibility is the main reason it is where it is I’m sure.

I moved the motor around in my dual extruder mod and it made assembly more difficult. I forgot to put the M4 nut in the base before I put the motor on, so it had to come off.

I upgraded my Prusa i2 to use the same IGUS bushings we use in the AO-101. I modified the X-axis carriage from the AO-101 so that I could rotate the extruder stepper motor out of the way of the threaded rod on my Prusa. I have not had a chance to try it on the AO-101 yet so YMMV.

x_carriage_for_igus_pillow_block_bearings_with_rear_fan_mount_with_rotated_extruder_mounting.stl (152 KB)

Thanks for the answers guys.

Orias thanks for your carriage, I’m modeling my AO-100 in FreeCAD with the few mods I want to do, I’ll import your carriage and see how it fits in. :slight_smile: