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Unread 30-10-2015, 19:15
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cbale2000 cbale2000 is offline
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AKA: Chris Bale
FRC #5712 (Gray Matter)
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Re: pic: Poly-carbonate 2 Speed Gearbox

Quote:
Originally Posted by Chris is me View Post
If you want to be extra safe against deformation, you'll want to upgrade to 3/8ths polycarbonate. 1/4" probably deflects too much, even un-lightened.

It doesn't end up saving you weight over an optimized aluminum gearbox, but it's hard to do gearboxes with polycarbonate.
Having built several polycarbonate gearboxes I would have to agree with this. If it were designed like an actual box, where you have polycarbonate connected on all 6 sides supporting itself you might be able to get away with 1/4" (as my team has in the past), but if you plan to support it like that, you'll definitely want to go to 3/8" for rigidity.

You might also consider mounting another plate of polycarbonate between the gearbox and the output sprocket. Having less distance between plates should improve the rigidity.

This is what we built a few years back. Note that the aluminum plate was eventually replaced with polycarbonate. Also worth noting that the gearbox is still around 8 years later. The gears failed a while back, but the box is still in great shape.

Last edited by cbale2000 : 30-10-2015 at 21:27.
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