Better thumb z-crank
Description
I liked ssd's thumb crank, but it was rough around the edges (literally and figuratively) and just didn't feel quite right. My finger kept slipping off of it when it turned, and I realized that it needed a narrower shaft to allow the finger to get some purchase, and I wanted to figure out how to make those sweet curved contours with rounded edges in OpenSCAD (hint: lots of toriods). This is the result. It works extremely well and feels disconcertingly good turning around the finger. Best of all, it's made in OpenSCAD, and is fully parametric.
Instructions
The hole should be about .5mm smaller than the rod (the STL is sized for the makerbot M8 Z-rods), and should screw on tightly, self-threading as it goes. Like ssd's crank, it should be tight enough to not need a set screw, but if you've got screwy tolerances on your printer that make it too loose, you can always change the bore variable in the scad file.
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rjbono
on
February 25, 2011
said:
This really worked well for me and saves a lot of time in setting up the z-axis distance.
ssd
on
February 1, 2011
said:
Very nice! I've been using OpenSCAD a lot, but I did my version in blender specifically because I didn't want to figure out how to do the filets and splines in OpenSCAD. I wish there was a filet function or something... (or spline for that matter..)
whosawhatsis
on
February 1, 2011
said:
It took a couple of days on the back burner before I realized how to do it. The concave corners were especially difficult, as it took a lot of square roots and arcsines to get the placement right, but it was soooooo worth it. You have to print one just to feel how smoothly it turns around the finger.
License
Better thumb z-crank by whosawhatsis is licensed under the Attribution - Share Alike - Creative Commons license.
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I like it, something useful. :-D