Here's my old Ryobi belt sander. It was friday evening and I was beltsanding away, excited for a long weekend of boatbuilding. Then this photo happened. No more teeth on belt. No parts suppliers would be open til tuesday. I finally found the part on the primitive interweb of the day for $30 with "allow 6 weeks" shipping.
Damn. I couldn't find any belts in my own bins with the right pitch, thanks to their weasel ways.
Aha! I thought, I'll make it a chain drive. So then I wasted a vast amount of time destroying the tool with a chain drive mechanism that never worked.
Don't do that. Get the real parts. These days it's fast and cheap. Those are quantitative improvements that have made a huge qualitative difference. Welcome to the new (but better) economic reality of tool repair.