While I'm sure that someone makes wheels (NWSL, maybe?), the easiest way to get wheels is probably to pick up a parts lot of engines on Fleabay. Just make sure the flanges are decent, and they're the right size, and chances are you'll get a lot of parts you can use.
Hey. I'm considering scratchbuilding a freelanced HO steam engine, and I want to know where I can get drivers for my locomotive. Moreover, if the driver pattern/size I really want is not available or out of stock, what do I do?
If the size you are looking for isn't in stock, you can wait until they are made by Greenway, or get a set that's close to what you need. The last thing is you could scratchbuild them, but without a lathe, and milling machine, it would be improbable that they could be built.
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In any case, Bowser has discontinued steam loco production and when they run out of spare parts what would you do?
Did you want to scratchbuild the entire loco or could you build a new stucture of an existing frame?