I needed one of these for cutting some thin tubes so I made one over the holidays for myself!
I found the idler wheel on an old piece in printing machinery but it's just a .120 wall tube that I added some contour to. The contact wheels are just aluminum bar threaded in the end for a paragon hole saw arbor. The tensioning trolly rides on long shoulder screws that allow belt tensioning with no tools.
The main frame just clamps on the quill like a seat post clamp.
I made it to fit standard hardware store belts and used pieces of material on the shelf so I could see if it works and it does just fine. The low quality belts are sort of a drag and I may have to turn down the contact wheels when I get some decent X backed belts.
Enjoy!
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frankthewelder, on Flickr
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