Broken steam locomotive drive bar

[victortorgrimson]

I was just finishing up adding a DCC chip to a 50 or so year old locomotive when suddenly a drive bar fell out of its wheel! Surprising since I hadn’t been doing anything to it. Anyway, I can see how to line everything up to reattach it, but I can’t figure out how to screw it back in. The pin that attaches it to the wheel is threaded like a screw, but it has no flathead, phillips, or any other groove to allow a screwdriver. The perimeter of the head might be hexagonal, but the piece around it seems tight to fit any tool around it. Does anyone know how I can screw this pin back in?
Thanks,
Victor

 

[Selector]

The pin you have loose is the main crank pin. I think your best bet, but being very mindful of the eccentric rod still attached, is to remove the affected driver axle and spin the entire wheel around the pin, inserting it nice 'n snug. You might try a locktite compound that will keep it from backing out. Then, being careful with quartering, re-install the driver and make sure the eccentric is angled correctly before you cover the axles.

 

[trailrider]

I can't tell from the photos if the screw is a hex head one. If it is, a Morris E-Z socket wrench set is the way to go. J.I. Morris in Massachusets has them. They are handy as heck for model railroad steam locomotives. If there is no clearance between the hole in the drive rod, you might need to try to wiggle it loose, and measure the diameter and pitch of the threads. You also need to measure the clear part of the screw shaft. You might call Morris and see if they would have a screw with a hex head, if you sent the screw to them. Otherwise, Selector's method might be your only other option.