1.75mm filaments are slowly becoming mainstream, due to the design choices of the commercial 3D printer manufacturers. That has recently caused me some long waiting times for 3mm filament, while 1.75mm rolls were stacked high…
Enter a reworked version of the ReprapPro mini extruder.
It is modified to use a 20mm M4 bolt in stead of the M3, with more readily available 624 bearings, and a new 10mm drive gear. The reason for the changes were that my 0.4mm nozzle started to block, but not enough to look blocked. This tripped up my airtripper, causing filament slippages, warps etc. I needed something that could cope with the pressure.
The drive gear is 10mm OD, 8mm long and tapped M4 in the center, with M6 hobbed wormgear on the one side of the barrel. I just edged off the two sides for it not to interfere with the sides of the 624 bearings.
This extruder managed to print past the blockage for an entire roll of filament. Of course, when I cleaned the nozzle, everything worked infinitely better, but in the end, I gained a foolproof 1.75mm extruder.
Bonus.
The stl files are added into the Morgan repository, but you can get the extruder sources here:
https://github.com/qharley/Extruder-drive
I like the compact design, and we’re an all-1.75 mm shop already, but I haven’t been able to figure out where you get the M4-tapped drive gear. Did you make that yourself?
Hi Bill,
Yes, I made it from brass rod in a small lathe. Yes, it is not a “standard” side drive wheel as far as I know, especially since it is a tapped drive gear, but it is worth the effort in terms of the extra grip.
I’ll post some detail on the gear.
Hi Quentin,
i try to reproduce your extruder …
but the link on https://github.com/qharley/Extruder-drive Page to
the http://reprappro.com adress didn’t work. Maybee you have a photo (or more) of an assabled extruder ?
greetings from Germany ..
Whiskey
I will add some photos later today… With some basic instructions
Have not forgotten yet… Have to get the photos off my device.
Hi Qentin,
maybee this Site may help others … additional Photos of your exsturder should be good always…
Greetings from Germany …
Whiskey
oh … the link i want to set isnt in my message *grrrrr*
http://reprap.org/wiki/RepRapPro_Mendel_Mini_Extruder
here it is …. so maybee usefull ….