How to fit odd belts to 18"/36" Delta drum sander

[george wilson]

I have a Delta 18"X36" drum sander. The drum is 5" in dia. It uses 2" wide belts .

I have a large bunch of 6" wide abrasive belts,enough to last me forever. Not wanting them to be wasted,I figured out how to fit them to the Delta.

You cut a long angle of 20 degrees on the ends. Make sure you cut the end angles on opposite sides of each end! The extreme length of the belt should be 61 1/2" measured point to point to the tips of each end.

This angle lets the edges of the belt mate up perfectly,and clamp perfectly at each end. Similar could be done to any drum sander,but their different diameters would change the angles,and the length,of course.

These belts I have are unused,but came off of obsolete overhead stroke sanders that used a very long belt,and took up half the shop.

I have some very fine belts(320 grit) that will never work on my drum sander. Rather than waste the good 100 grit belts,I used a 320 grit to develop a pattern.

[Chris Padilla]

Thanks, George. Your post intrigued me to use geometery to try and come up with a formula that anyone can use to "configure" a belt of any width (within reason) to a drum sander. There is probably one out there on the 'net but I haven't been able to find it and well, this is a challenging problem and fun to work through. Hopefully I can post a solution soon. :)

[Wes Grass]

Correction: (forgot the belt gets 'wider' as it's angled on the drum)

ArcSin(Belt Width/Pi*D)

Or on a PC calculator:

Belt Width '/' Drum Dia '/' Pi '=' 'Inv Sin' (not Tan as previously posted)

Georges comes out to 22.5°.

[mreza Salav]

There is a simple way without calculations. Take a piece of string and turn around the drum to find the circumference of the drum. Then put that at an angle on the belt until it touches to sides. It gives you the angle you need to cut.