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Unread 08-09-2015, 20:05
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Re: Bearings vs Bearing Blocks

Hole saws and similar hole cutters can get you a hole close to 1.125", but it's going to be inaccurate, both in size and in center position. Probably good enough position for an intake roller or something, but not good enough for a gearbox or exact centers on a drivetrain. The real problem is size though - you're going to have a really loose fit on the bearings, and they'll easily fall out. Bearing holes are almost always a circumstance where precision is warranted.

Quote:
Originally Posted by Ari423 View Post
The tricks is to use a piece of plastic block (I believe we use HDPE) with a semicircle cut into it on one side. The block is bolted onto the chassis semicircle side down and the live axle sits in the semicircle. The weight of the robot and the bolts holding on the gearbox keep the axle seated in the cutout, and the plastic has so little friction that the axle turns as if the plastic were a bearing. This also allows us to easily remove the gearbox, wheel, and axle without having to remove the bearing, while avoiding cantilevering the drive axles.
Honestly, I'm glad it works for your team, but this is a really crude and sloppy method of supporting an axle that adds a non-negligible amount of friction. It's not a good solution to this problem.
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Last edited by Chris is me : 08-09-2015 at 20:08.