I've wanted a little Struck mini dozer ever since I was a kid and with the machine tools I have now (and the scarcity of the crawlers on the used market), that made the decision to build one from plans an easy one.
The plans I have are of the MD-40 version which looks similar to this:
The bulk of the tractor is made from 10 gauge plate which I'll have laser or water jet cut from .dwf files, and from common bar stock shafting, pulleys, etc.
The plans are pretty detailed but I'm getting hung up on finding the cast iron sprockets they refer to as "22 tooth #55 agricultural chain cast iron sprocket" and the #55 "track" chains which act as track rails. The plans also list a "heavy duty" chain as being available in the same #55 pitch which I would rather go with than the ligher duty version.
My question is, do you guys know what the current equivalent standard designation is for #55 chain and sprockets, and where I might be able to source them. Googling around turns up a lot of hits to Chinese sites but I'd rather source something locally. The #55 chain used also has tabs on every link that the track shoes bolt to, with holes at 2 inch on center.