Quote:
Originally Posted by cxcad
...honestly I really don't understand how 254's system works. Can anyone shed light on that?
|
This picture should help. The way I understand it, the bearing block is being pulled to the left by the left by the chain (not installed) until it contacts the side of the cam, as the cam it turned counter clockwise it pushes the bearing block to the right, tensioning the chain.
Quote:
Originally Posted by Chad987
|
Very interesting that in practice the friction of 4 bolt heads on the drive rail is enough to keep tension where theory says thats probably a bad idea. I will keep this in mind, thank you.
I guess now is a good a time as any to post what MOE uses. This is the first year we ventured into the realm of cantilevered drives after the unmitigated disaster that was mecanum in 2013 (If I called this a WCD someone might shoot me
).
We wanted a belt tensioner that did not rely on friction and we came up with a few ideas. (My favorite was a roller spool that we could change the diameter of to increase tension.) Ultimately we used
what is shown in these pictures. There is a curved slot in the drive rail that the shoulder bolt can move through. As you tighten the bolt sticking out of the top of the section of U channel it raises the shoulder bolt and the roller on it pushing the belt up and tightening it. The countersunk 1/4-20 is the pivot point.