pic: 114's new tensioner

[Madison]

Originally Posted by Ben Piecuch

We're looking at implementing a cantilevered drive system like this, and am wondering if those bearing blocks are absolutely neccessary. We'd rather just bore the 2"x1" rail to accept a flanged bearing/bushing, and not have to machine a "complex" bearing block. Are teams finding that the 1/8" rail wall isn't strong enough? Or is the support span on the axle too narrow for the applied torque? Or, are teams simply not following the KISS rule and making unneccessary machining for themselves?

If we have to go to a bearing block setup such as this, I do really like the tensioner outlined here. I agree that it can be made simplier, maybe out of just one piece. How does the cross rail mate up this to assembly, and does that connection (bolted or welded?) interfere with any of this?

Thanks,

Bengineer
Team 228

To my knowledge, 195's 2007 chassis was built as your describing -- bearings pressed into 1x2" tube.

We use bearing blocks because I can mill a set and some extras in an hour or so on our mill and they're easy to replace in case of some catastrophic failure. Our mill's travel is only 20", so I can get accurately spaced bearing holes into a frame member in one operation and we're very likely to screw that frame member up on some other way down the line. Bearing blocks minimize the time spent redoing work, I guess.

I wish there were some better, more considerate reason for our process. But, with the time constraints we have, taking baby steps is preferred -- even if they're more complex -- than putting all of our eggs into one very complex, important basket. Of course, I understand the definition of "complex" varies from team to team. We have awesome machining resources, but none of us are great machinists, so we work with what we have.