Beltsander Question

[ctxman]

I recently acquired a shopsmith with beltsander attachment (actually i bough ti to make a mini as a sanding station). I watched the Sawdust session #12 where Nick describes how to take it apart, clean and lube it.

It's hard to see in the video but at one point he spins the tensioner drum and shows that the good one spins very freely, and the one he is working on doesn't move very much at all.

Here's my question. On the one I'm working on, the bronze bearings seem fine and there is no play with the shaft/bearings. I cleaned the shaft and lubed it with lithium grease. When I extend the spring and pull away the 2 cams that flank the drum, the drum spins very freely. When I release everything back into position, the drum still does not spin very free. It's not stiff, but it certainly doesn't continue to spin like I would expect it to do. It seems that the amount of tension, or pressure of the 2 cams against the drum is keeping it from spinning a lot. Perhaps everything is correct, but i'm wondering if there is a way to change the amount of pressure against the drum or is that spring and roll pin set and non adjustable?

Thanks