GEARED BOWDEN EXTRUDER

thingiverse

UPDATE: I've remixed this design to mount on a 20/20 aluminum extrusion https://www.thingiverse.com/thing:2596124 UPDATE: So I finally got around to sorting out the support structure for this design, and it's much sturdier than before, with fixing holes in a better position. UPDATE: I had the fixing post for the idler block randomly snap mid-print last night, so I looked at the design and found a weak point - the narrow fixing post. As a result, I made it wider to reduce the likelihood of this happening again. So here's my take on a Wade's Extruder. If you check out http://reprap.org/wiki/Wade's_Geared_Extruder, you'll find a description of all the components. I made some changes to the general design - like having a hinged idler block that's put under load with a single bolt or spring. I didn't see the benefit of four, and thought it was actually a disadvantage. The idler pulley is held in place with a 16mm M8 cap head bolt instead of threaded rod or bar, which means you don't have to cut anything. All the pulleys are fully supported now - many people only partially support them due to issues with support while printing, but I got around this by bolting the extruder block to the motor support with 8mm M3 bolts and captive nuts in the motor support. Tolerances are tight, so I found a pair of long-nosed pliers useful for pushing the nuts into place. All pieces can be printed without support now. The hobbed bolt is the cheapest one I could find on Aliexpress ( https://www.aliexpress.com/item/3D-printer-accessory-Wade-s-extruder-hobbed-bolt-reprap-M8-wire-feed-teeth-space-1mm-for/32387428107.html?spm=2114.13010608.0.55.de7dUS ) and the setting out of the extruder block is to suit - there's just enough room for a nyloc nut. The motor mount/support is just a temporary solution at present, but eventually the extruder will be mounted on an enclosure frame. For now, it's screwed down to the bench, and the motor fixing holes aren't quite in the right position - they were off a previous design, which means you can't get at them with the gears in place. Not too much of an issue, though - you can just bolt the extruder block straight to the mount after the gears are installed. The small gear and the outer toothed ring of the large gear were originally designed by someone else, but I'm afraid I forgot where they came from. If they're your design, thank you very much for saving me a ton of time! I've tested this design for about 100 hours now and fed around 350m of filament through it - it works amazingly well, and the only problem I had was a failed pneu fitting that decided to release the Bowden tube 10 hours into a print, which resulted in some serious swearing. You don't even need to lift the idler block to change filament now - once you get the compression of the spring right, you can just insert filament and press extrude. There were more build photos, but for some reason Thingiverse decided to eat them or something, so they won't display. I'll try again at some point.