Belt grinder advices

[Toolmaker51]

1,5hp - 2800 rpm is a lot of power and speed. A speed control might help if the calculations are too high drive ratio, and to handle different materials nicely. The belts you have will last a long time, spreading wear over more area than my 42'' (1066mm).
4 wheel sanders are called 'square wheel'. Typically there is a removable plate for smooth free-hand contour sanding. The plate makes it more like a grinder, to achieve flats, radius corners or chamfer edges.

... large or small diameter in the final "cutting" wheel. Larger wheels and 3 or 4 reduce belt stress, compared to bending around small wheels. Mine is 3500rpm and about 4'' drive wheel, upper about 2''. Mainly I think that is to gain distance between wheels. 42'' is not a common hardware store size. I ebay them.

Width to me = wider is better. Cutting them narrow could break the band of fabric or stretch unevenly. Design the plate to move side ways a little so you can sand right into a corner

-Adjustable wheel for centering I see has "tip", between 5 and 10 degree, It can be useful? That's the adjustment an eases the belt on without any tension. Mine sounds just like what C-Bag describes.


- engine pulley diameter, ... same as motorcycle gearing for different engines. Mine's 3500 rpm sometimes faster than I want. It sands wood fast enough to burn with a fine grit. Grinds metal well, iron or aluminum. Haven't found a belt good for thermoplastic, [those that melt], has to be brand new sharp. I think you could reference commercially made sanders for rpm they run in, but to actually to vary speed is way better. We'd probably use a step pulley.
Being able to change speed will allow a range for polishing too.