Friday, January 23, 2015
Preparing for the Walschaerts
The biggest worry with the railcar kit is all the waggly bits going on at the powered end.
I've tangled with Walschaerts valve gear before and learnt a few lessons. The key is to anticipate problems and try to build them out before you start.
Most of the "fun" will be at the cylinder end so I've been trying to do things right here. First up, the wheels have been shimmed to remove all sideplay. It's going to be tight behind the crossheads and you don't want any sideward movement resulting in things banging in to each other.
Crank pins are fitted with a little superglue on the thread so they aren't going to unscrew themselves - it can happen and only results in badness. While I'm putting things together, plenty of black paint goes on as I'm not going to be able to take this thing to bits again to do that.
Thinking about the clearances, I don't use the Romford rod retaining washer as it's a bit fat. Some tiny brass jobbies with hardly any thickness are more suitable. Soldering these on, I've coated the rod with permanent pen to stop errant solder sticking where it isn't wanted. A bit of aluminium foil provides a little spacer and again, stops the solder in it's tracks.
The rods themselves are very nice. Etched in thick nickel silver, there's no laminating required. A tiny spin of a broach in each hole was enough to see everything running smoothly too.