Traction Tire Debacle: Bachmann 2-8-4

[mkearns]

So I've got a Bachmann C&O 2-8-4 with plenty of miles on it. The original traction tires wore off. A buddy helped me out with some Bullfrog Snot but it didn't fully restore the pulling power that it had originally. Wanting better performance I decided to actually replace the traction tire. I have a few spare TT for this occasion and have replaced them on a few other locomotives, so I (mostly) know what I am doing.

Welp, it turned into one of my more epic modeling debacles. The first screw I tried to loosen that held the rods on the driver broke off at the head with barely any force. In for a penny, in for a pound at this point. The second screw mostly stripped. With herculean effort I finally got it to loosen.

So now my drivers are free of the rods and I removed them from the locomotive. Yay! But there's no way I can replace the TT and use the driver set as is: One tiny screw is still in it's hole but with no head and nothing to grab. The other screw is basically, well, screwed (stripped head). So my beautiful 2-8-4 went from weak to fully inoperable.

I'll talk to Bachmann CS and see what they say but the parts I need are not listed on the Bachmann site, only a full replacement chassis which feels like an overkill, and expensive, way to solve my problem. I'm posting to see if there are any bright ideas in the hive mind. Or if anyone has some Bachmann 2-8-4 drivers and screws in their parts bin? Thanks

[mmagliaro]

I'll wager that metal those crank screws are made of isn't the strongest metal and therefore can be drilled.
I suggest drilling out the remaining piece of pin down in that hole with a pin vise, and then retapping the hole for a new screw. 
Yes, they do make taps that small.  I have no idea what the exact size is on the Bachmann Berk, but probably something like
an M1.0.  I would start by taking calipers to the remaining screw to get a measurement so we can guess at the thread size.

Even if it isn't exactly M1.0, as long as it's close, you can retap the hole and put a new screw in there.
It could be smaller, but you can buy M0.8 and M1.0  taps on eBay for about $10. 
They are not super strong taps, but they are usually okay for something like this.  I wouldn't try tapping
steel with a cheap tap unless you want another hole plugged with piece of metal.

As for the crank screws...
https://modelmotorcars.com/collections/small-parts-hardware
Metric micro bolts in sizes from M0.5 up to M1.0 and larger.
They have hex heads.  You can finagle them in with some tweezers and small needlenose pliers, or...
modelmotorcars also has "socket wrenches" (really just nut drivers) in M1.3 and M1.0 sizes which fit their M1.0 and M0.8 hex
bolts, respectively.