Belt grinders

[Max_Power]

I'm sure this is a dumb question...But I'm curious as i have seen a lot of references lately to belt grinders. What is the difference between a "belt grinder" and a "belt sander"? Is there some reason why someone couldn't build a stand for a common carpentry(like 3x21) type sander with a small shelf(maybe called a platen?) for light hobbyist metal use? Thanks in advance, Todd

[darryl]

Sure, it could be done. The physical construction of a typical belt sander isn't the best starting point for a stand model, but it could be made to work. I used to clamp mine upside down in the vise. I've used it on wood, steel, aluminum, plastics, rubber-

Belt speed might be an issue. For some things it could be too fast or too slow. They usually have a high speed universal motor with its own cooling fan, so even though a speed control would work, you could overheat the motor if you slowed it down too much.

You would have to pay some attention to how the platen, which is part of the machine, and any fence you add would link up mechanically. You wouldn't want flex between those parts or some workpieces might tend to get swallowed- wrecking the belt, maybe the machine, maybe parts of you-

[wierdscience]

Sander = smoothing/polishing
Grinder = shaping/stock removal

Sanders are good for deburring,cleaning edges off that sort of thing.If you want to remove stock to a layout line or remove weld or cutting slag then you need a belt grinder.
A belt grinder will have more raw horsepower and run much more aggressive belts.The one we had at work runs 3hp and carries a Zirconia belt.With a 36 grit belt it peels little fish hook shaped "dust"off work pieces thick enough for them to form.
If given the choice between the two I would take the grinder.Simply because with a belt change it will do everything the sander will too.

[loply]

Essentially a belt grinder is a belt sander on steroids.

Much bigger belt heats up less and thus can handle more stock removal, and bigger horsepower.