Tuesday, March 31, 2015
Railcar motion problems
Regular readers will have noticed a distinct lack of action on the GWR Railmotor over the last few months. This is partly because I have been very busy with other jobs but mostly because it's time to look at the waggly bits and I've had to summon up some courage.
Deciding I couldn't put it off any longer, I dug out the kit and had a look.
First off, the motion bracket is supposed to be held to the chassis with a self-tapping screw. I didn't like that idea much. For a start it will be fuggly. Then, unless the pilot hole is drilled very close to the size of the screw, I reckon the whitemetal will distort.
No, I have soldered it using 100 degree solder and some no-clean-up flux I have for testing. Time will see if this goes green. It smells nice when heated but I'm not sure if that's a good sign.
Next, the crosshead. Made of spindly whitemetal, I have a number of problems with it. For a start, the fit is terrible. After cleaning the slots and refining the slide bars, I made it move acceptably freely. Then I looked at how it should be attached to the connecting rod and find this information missing from the instructions and diagrams. I think you put the spigot on the back through the hole in the rod and then solder a washer on the back. It's an interesting idea but when this gives up the ghost, I'm going to be trying to solder in some confined spaces to fix it.
On the front, there is a link to be attached with glue. Of this hangs the union link and this is attached with brass pins soldered with normal temp solder. Hmmm.
I think the best idea is a lost wax cast crosshead. The channels that run along the slide bars are 4mm apart. Any suggestions for a supplier?