pic: Sliding Wheel Chain Tensioners

[Ivan Helmrich]

We did something similar but used a short section of 1" 80-20 instead of tube. No need to slot the frame, the slot in the 80-20 worked fine. We just drilled a 3/8" hole through the 80-20 to hold the axle. We used 2 bolts from the bottom up into the slots. I think this is about the same thing you proposed in your second post. It worked really well but I'll be interested to see if it will hold up when the floor isn't so slippery. The loads on the wheels were pretty low this year. I guess a scheme with a bolt threaded into the end of the 80-20 would make it stronger as would using more bolts from the top or side.

One thing that was a problem was that a couple of our corner blocks were a little thin. The channel got a bit squished and the wheel mounts were too tight. We solved this on the belt sander but it was kind of crude. Next time we'll shim around the corners if needed.

You have a good design there, lighter than the 80-20. I'm curious if your axle holes got oblong. I was a little worried about ours but it seemed to hold up fine for the one regional we went to.