I've finally got my little Loagan Model 200 up and running. Seems to be nice and tight, cuts the nicest collection of steel wool shavings I'veseen. But as soon as I try for some heavier cuts, the belts either slip or pop off. The Logan has a 25 pound belt guard on the top that actuates a cam to tighten up the flat belt. Easy to adjust the bolt but how tight to set it? I can't get at the belt to see how much deflection it has once the guard comes down, can't do it with the guard up because the cam isn't actuated. Belt appears to be some sort of fabric deal, not leather. Help??