I've found a really nice solution for mounting printed parts on to motor shafts (D shafts or even fully round shafts) in the 2mm diameter to 10mm diameter range. It takes torque pretty well, but is a bit bulky. Does anyone have any idea how I might do the same thing within a much smaller space?
My present solution, see the image for a CAD diagram, takes about 18mm of length along the shaft, and needs a surrounding area of a diameter around 30mm. It will easily take 10s of kg*cm for a 6mm D shaft, and happily take (haven't tested to the limit for this one) many kg*cm for a round 3mm shaft.
Grub screw based systems, where a nut sits in a hex shaped gap in the plastic and gets pushed outward against the plastic as you tighten a screw through them to clamp against the shaft, are a lot less rugged due to the deformation (and likely creep over time to) they cause to the plastic. My design's both-sided clamping action is much stronger.
But have you any ideas how I could make it, or some other equivalently strong clamping design, smaller?
Where 3mm round shafts are concerned, I'd really like something that could fit within that tiny gear, or the little conical region behind it, on the end of the one in the diagram. But that gear is only 1mm tooth-tip-to-tooth-tip, and has only 5.8mm diameter in the area within the dedendums. The gear is only 7mm in length, and the cone behind only gives an extra 4mm of length with a 19mm diameter.
I can 3d print any shape from plastic. I've got all the nut and bolt sizes one can likely need, I could also order more 2d lasercut metal pieces (4mm or other thickneses) but would rather not as it was fairly costly to get a big batch of those I show in the design and am already using in all and any projects where I need to clamp a print to an axle shaft. I don't presently have any means available to make custom made metal pieces which are anything other than 2d lasercut type shapes.
Thanks