B'Struder - M Prime One

There are many extruders on Thingiverse, but to use them with an M Prime One printer and feed filament through the frame (rather than around) in the manner of the M Prime One Beta Extruder (http://www.thingiverse.com/thing:1157764), one ends up using a NEMA Motor Bracket. Unless modified, NEMA brackets don't fit between the smooth-rod brackets and have to be mounted higher up on the frame.

When I first came across the B'Struder Universal Bowden 1.75mm Extruder by tempo502 (http://www.thingiverse.com/thing:711401), I was quite impressed by the design and decided to try adapting it to my M Prime One printer. Using FreeCAD I did come with a working model, but I wasn't really happy with it.

Barrocas published several remixes to the B'Struder, including http://www.thingiverse.com/thing:2243325 and http://www.thingiverse.com/thing:2270622. These remixes modified and added the two lever design and the side lock lever. Both desirable features, but I still wasn't ready to retry remixing it for the M Prime One.

When spegelius published the B'Struder - E3D Hobb-goblin edition (https://www.thingiverse.com/thing:3078503), he also provided access to his OpenSCAD source code and library files. NOW IT WAS TIME TO TRY ANOTHER REMIX.

Thank all of you for sharing. Esp. spegelius, your debugging section tought me more OpenSCAD than any other single project, book, ...tutorial that I have studied.

I made designs for MK7 and MK8 gear:

• the motor mounts are re-designed with an added plate for connection to the M Prime One frame
• the arms are basically original, except "warts" are added to the ends to increase contact with the locklevers
• lock levers have an other 'arm' (spegelius idea) which is needed for operation, the lock arm length is adjusted to clear the extruder gear
• lock levers are to be installed with M3 washers top and bottom
• the arm's filament path needs to be drilled open. See post-printing
• MR105zz_support basically original per spegelius design
• spacer
• new spring cap

Most of the original instructions and part lists apply. You will need a bit longer than 25mm M3 bolts for this.