j-head bracket with servo mount 3mm and 1/4th inch coupling

thingiverse

I liked Biomushroom's j-head design with bracket, so i re-worked it with a 3mm filament hole and adjusted the pnumatic coupling hole to work with a 1/4th inch coupling. I used indieflow's scad files to create the base model, and i attached biomuchroom's mount. i removed the supports (the ones biomushroom made were nice and worked well, but i feel safer using supports made by a slicing program) and made them a little bit simplier. I also added a modified version of the main part of indieflow's direct drive extruder. This one is redesigned for 3mm filament and the larger coupling. I haven't yet tested it with the mk7 drive gear, the filament hole might need to get adjusted. I printed one out and it worked OK, however i've been making a few more modifications to get everything working right. I'm tracking my changes on github:https://github.com/monofuel/Prusa3 and i'll keep the latest mono_bracket.scad up-to-date. This one currently does not have the servo-mount. changes i've made for mono_bracket: i had issues fitting my 3m cap screws and my 3m philips scrws into the holes of the j-head clamp, so i increased their size a little bit. I also had issues with my screws threading into the clamp. I could have reamed the holes, but i decided to make them bigger on the model. i modified the size of all holes ment for 3m screws to be 3m. The origional design used slightly smaller holes for self-tapping screws (with the exception of the two holes on the top) however I went with using a tap and die kit to thread each hole. the 3/8ths with 24 pitch pneumatic fitting hole was hard to thread and fit rather poorly, so i made the hole deeper. It's still 1mm short of fully screwing the coupling in with the latest version, but to get the additional inch would either mean leaving no plastic between the coupling and the j-head, or increasing the height of the bracket. I adjusted the filament hole to 3.4mm. i tried 3.2mm, but it ended up as a rather tight fit for filament. I haven't made any modifications to the scale of each part, as they all fit together correctly on my printer. Any changes i've made have comments on github.