As I mentioned before, my project partner and I decided to re-use the belts from an assortment of printers and scanners, which meant we needed to design pulleys to go with them.
Yet again, the laser cutter proved invaluable, allowing us to try design after design until we no had perfect meshing. Griffin did the measuring and modeling with calipers and Inkscape, I worked the laser and assembled the four layers needed to create a pulley from a flat sheet. We used an acrylic solvent glue, and they're now single solid objects. They fit the M8 rod perfectly, and are then clamped down with nuts and washers.
The motor-fitted pulley still has some issues however, as neither of the versions we have tried are quite right. Luckily, we have tons of plastic to work with, so the limiting factor is (as usual) time. I hope to report back with success tomorrow.
If I ever figure out what model printer the belts came out of, I'll upload the designs to thingiverse.
Ben
ReplyDeleteIt looks like the laser cutter cut the teeth of the pulleys on a slight taper. I imagine this is because the beam spreads slightly through the thickness of the plastic. The reason I'm writing is because it appears that you have the two "narrow" sides of the toothed disks facing each other.
While this is intuitive for belt tracking, it turns out it doesn't work half as well as flipping the parts and making the toothed section "barrel" shaped. This will cause the belt to track in the middle so well that you may not need the guide flanges at all.
I hope this helps, let me know how it goes.
Chief Geek
I finally noticed that there was a comment, horray I've been noticed.
ReplyDeleteThanks for the advice, why does the belt do that?
I have not seen the belt move from the center, but I have also only tested moving the platform by hand.
Making new pulleys is by no means difficult, and whatever's most accurate is what I'll try to do.