Hi Bo
The tension block that carries the driven wheel's axle is loose on its guide rails in most? saws I've seen.? I reversed the rails (so? the slots in the axle block run on the other side of the rails) on mine because where they originally ran was thinned on my rails.? I don't think it actually matters very much, as when the blade tension comes on it pulls it all rigid anyway. Play here is not the problem.
The normal reason for the blade cutting into the guide bracket?when it derails (its happened to me), is for the side guide rollers to be set too far apart (too much blade to side roller clearance) and/or the guide bracket being too far forward. Either almost zero clearance or John Pitkin's 7thou clearance work without the problem you experienced.? Both rear guide rollers should be back far enough so BOTH only turn intermittently when adjusted properly - put some diagonal lines on each bearing with a Sharpie so you can tell when they are turning.
A full alignment will cure this - jv
