Rockwerks Lapidary Forum

My grinder came with an 8" expanding drum on it. I have no idea what brand it is but I know its not a Rayspan. I bought some SC belts for it not knowing what diameter I needed. The belts are too loose and slide off of the drum as I use them. First off, how do I tell what brand drum it is or what size belt I need? Second question, any idea how I could safely rig it to use these belts to stop them from sliding off? I do plan on replacing the drum eventually with a Rayspan but for now I want to try and use what I have.

Tony, you may have a Lortone Exact spand drum. It requires belts that measure 3'' x 25 1/8''. The Expando drum uses belts that are 3'' x 25 7/32''.
Look at the top two entries on this page to see the difference:
http://www.kingsleynorth.com/skshop/sea ... 5&count=14

You can try putting on the new belt over an old belt already on the wheel. Doubling up the belts may make it tighter.

Im no help here....I just bought my 6" drum and then bought 6 inch belts and they fit fine no matter what brand. You must have a specific drum like Joe mentioned.

I thought it might be a Lortone. I think I ordered belts for a Rayspan which explains the difference. Thanks Joe, I'll try doubling them up.

Why on earth were they designed with a 3/32'' difference? I mean... really!
Hope you can make 'em work.

Look inside the belt, are there arrows pointing in one direction? If so, install the belts with the arrows facing the direction of expandable wheel will turn. The best way to find the diameter of your wheel is to use a string to find the diameter then measure the width, they usually come in 1.5, 2.0, 2.5 and 3.0 inches in width. There are several good web sites that offer different size belts. Check out Bernies Lapidary shop.

rocknut

What the heck. I have the same problem. MY belts were wearing down so I ordered a whole load of belts from Kinsley and they are looser than Government spending. Oh boy, I was planning on cabbing, I had doped a bunch of stones and even flaked on a Wednesday night gathering. Boo hoo...oh I was so in the mood.