flex capable geared bowden extruder

thingiverse

I didn't want to wait for bearings to ship out and decided to use the hardware I had on hand, but I like this design so I modified it to suit. This version is similar to the original, except for easier-to-print filament path breaks (removable) using 608 bearings throughout instead of 625zz, a standard m8 hobbed bolt, and slightly altered filament paths to fit new specs. Still suitable for 1.75mm filament with ptfe tube fed right up to the hobbed bolt and trimmed flush with the beak profile on the output side. I also got lazy when remaking the filament clamp, it now screws down with a couple of m3x15 screws threaded directly into the plastic; not ideal, but I had some self-tappers in the scrap parts bin.... Print the body with supports and pause the print at no higher than 17.7mm (17.5 is better) to insert a segment of ptfe to act as a support for the upper beak. Only necessary if you're printing the one without the replaceable beak. When using the replaceable beak, install the beak and the hobbed bolt before adding the top bearing housing so that the hobbed bolt can tilt slightly to avoid damaging the beak. The beak is also slightly larger (too close) so that it touches the hob, allowing you to turn the hobbed bolt, grinding away the beak slightly so as to make a perfect fit with no gaps whatsoever. Retains the gears from the original, just modified for a normal hobbed bolt, or design your own for a custom reduction ratio. Made a bearing spacer for behind the spur gear. A .fcd file is attached so you can edit the height to suit your hobbed bolt. Edit; The "v2" files are further modified to make the ptfe tube fit better and so that the beak part restrains the filament even better and is removable/retained with a m3x17mm screw (17x2.85x0.5) so that the beak can be printed in a more optimal orientation; it will now print much better and do so without supports, when oriented as in the "plated v2" file. Now the only part that requires supports is the extruder main body.