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Unread 29-10-2011, 09:39
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Re: High Tensile Sprocket Bolts

Quote:
Originally Posted by Spirator View Post
our robot managed to shear the drive sprocket off the centre wheel.
You need greater shear strength, not tensile strength.

It is possible that the fasteners were not as tight as they should have been. Loose fasteners in this application puts a lot of shear force on the fastener. Make sure they are torqued properly and use self-locking fasteners.

The goal is to use the clamping force of the fastener to create enough friction between the joined pieces to that the fastener is only in tension and not in shear.

Increasing the hardware size can help, but you can even shear 1/4-20 bolts if they're loose.
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