Thanks, all good ideas!
George In Midcoast Maine, 'bout halfway up the Rockland branch
With a boxcar, you can use a longer screw that projects inside more. Glue a piece of suitably thick styrene above the bolster, then drill and tap the hole for the truck mount screw through both the resin underframe and styrene above it. The styrene will hold the threads well with minimum fuss and muss.
Mike Lehman
Urbana, IL
You can drill a regular hole and glue in a machine screw anchor.
Ulrich:
I was thinking the same thing about the durability of the threads.
Your idea of glueing a nut to the frame can be a bit tricky. I did the same thing with my McKeen Motor Car to attach the chassis to the body but I had a heck of a time with the glue fouling the threads. I tried both epoxy and CA. I tried to clean the threads with a tap but the force required broke the nuts loose. I finally ended up applying enough epoxy that the nuts were literally buried in the stuff and then I slowly and carefully tapped the glue out of the threads. I don't think that much epoxy would look very good on the bottom of a box car. In my case you couldn't see it once the chassis was in place.
My suggestion would be to use wood screws with as coarse a thread as you can find. Drill a hole smaller than the screw thread diameter, and then make a tap out of one of the screws by cutting a groove vertically through the threads. Hopefully that would allow you to cut the coarser threads into the frame. The trick would be in installing the permanent screws. You would have to be very careful to start the screw properly so that it engages the threads in the frame instead of destroying them.
Anyhow, that's pure speculation on my part. Surely there must be some N scalers on the forum that would know the proper way to do it.
Dave
I'm just a dude with a bad back having a lot of fun with model trains, and finally building a layout!
Resin is a rather brittle stuff and I doubt that the fine threads of a tapped hole will hold for long. How about glueing a captive nut to the frame?
George,
If an 0-80 screw will pass through the truck's opening, that sounds likely and is easy enough to find. If the fit is sloppy loose, go up to 1-72 or sleeve the center pivot with a short piece of brass tubing.
3/16" long may be enough or go up to 1/4" length.
I am starting work in an HOn30 27' Sandy River & Rangeley Lakes Wood Boxcar from Funaro & Camerlengo. I have a set of Micro Trains N scale trucks for the kit. The truck instructions talk about friction pin mounting in existing holes on N scale boxcars by Micro Trains, Con-Cor and Bachmann, but give no guidance for "non-standard" mountings. We have a couple wood kits that mount trucks with small wood screws.
I would prefer to mount the trucks with a machine screw into a drilled and tapped hole. Can anyone give suggestions on the type and size screw that would work?