Rostock Micro Extruder Mount
by jpickens, published
For mounting Ultibot Microstruder under the print platform. This extruder uses the PG35L Minbea geared stepper. In order to fit it onto the Rostock platform, I decided to mount the whole shebang below the platform. It weighs exactly 200g with the mounting screws, and after trimming the unused base mount part of the Ultibot extruder. http://www.thingiverse.com/thing:39098
I tried mounting above the platform, but either the extruder or the motor would hit the diagonal rods, constraining movement and/or "twanging" the deltabot.
What this thing does is mount to the mounting holes for the stepper opposite the extruder, giving somewhere to attach the assembly to the print platform. The "Under Extruder" block wraps around the motor, so long 3mmX40mm mounting screws, like the ones for the filament idler, are used.
I was going to modify the files for the Ultibot micro extruder, but the Alibre file was too complicated for my skillset. The nice thing about my solution, is that it may fit many other extruders using this same lightweight stepper, as the mount locations are set by the motor, and not the particular extruder you want to use.
Print with one shell, at least 50% infill. The STL doesn't have holes for mounting to the print platform. This allows mounting to be adjusted for your extruder location preference.
I drilled two 9/64" holes and tapped them to 4mmX0.7pitch on center 43mm apart to mount directly to the platform. The long side will be a blind hole, the short side could be drilled through and attached with a washer and nut for extra strength.
I am building a Johann's Rostock printer with 666mm active rod length. With the reduction in build height due to the low hanging extruder, I should get about a 250mm Z axis build height with a heated build platform installed. This is acceptable for me.