search

scottbez1 / splitflap

DIY split-flap display
https://scottbez1.github.io/splitflap
Other
3.09k stars 257 forks source link

CAD: Tweak Spool Fitment Values #122

Closed dmadison closed 3 years ago

dmadison commented 3 years ago

On my latest order from Ponoko (3 mm acrylic) the spool struts are still loose and will need to be glued. This increases the interference a bit more (+ 0.04 mm) to hopefully reach a point where the struts will fit into the spool and hold there by friction alone.

Also increased is the flap width slop, in a reversion to the change from #114. On my order based around f4e7714 the flaps do fit and swing but it's tight - a little bit of misalignment with the spool end pieces or burrs on the parts will cause them to bind. And after gluing the end pieces in place not perfectly parallel (+/- 0.15 mm across ~48 mm diameter) that's exactly what has happened: some flaps on the spool do not 'flip' freely which breaks the whole display.

Originally I thought a slight increase to the flap slop would do the trick, but after giving it some more thought I think the slop decrease should be reverted in its entirety. It's one of the only critical dimensions in the design that can break the entire display if it's too tight, and there are too many factors that can influence the total clearance. Better to play things safe and keep this loose. If there is continued binding due to misalignment of flaps within the spool, the spool_width_slop value can be increased further.

I also parameterized and slightly reduced the magnet hole interference. On my displays the magnet press-fit is tight and I ended up cracking one of the spools. The magnets seemed much happier and still held tight after some light sanding of the hole, so this value is being reduced ever-so-slightly.

scottbez1 commented 3 years ago

Good catch; agreed on reverting the flap slop.