In yesterday’s post about lunch with Chris, I mentioned my frustration with the three-axle trucks under my passenger cars. As I noted,
I’m fed up with the less-than-perfect performance of the six-wheel trucks under my passenger cars and with Chris’ help I plan to fix the problems. (The passenger cars run well about 90% of the time – but that last 10% of frustration needs to be addressed. There’s no reason they can’t be 99.9% reliable.)
Dan Vandermause wrote in the comments section to ask about our plans. Dan – thanks for writing. As you noted, these trucks are a real problem.
I would love to see someone like Dan Navarre at River Raisin Models offer a set of replacement three-axle trucks for the American Models heavyweight passenger cars. Maybe if enough of us ask? Dan has done runs of trucks before – his website lists a pair of Triple Bolster (four-wheel) passenger trucks for SP, UP, NYC, PRR, and IC. So it’s not unreasonable…
Failing that, though, I’m looking at the rigid beam compensation system many British modellers use for their equipment. This has been written about extensively – Google “Flexi-Chas” and you’ll see what I mean.
There’s an excellent book by Mike Sharman, published by Oakwood Press, that explains the system and offers several examples of how to deploy it. It’s out of print, but used copies can be found fairly easily online.
There’s also a great online resource by Russ Elliot called The Principles of Locomotive Suspension that covers many configurations. The configuration used for an 0-6-0 is perfectly suitable for a three-axle passenger truck – and can be found in Section 15 of the Principles. For American Models three-axle trucks, one outboard axle would be rigid while the centre axle and other outboard axle would be linked with a rigid beam compensation system.
My plan is to create a kit – principally, an etched fret – that builds into a subframe into which the wheel sets would mount. This subframe would also include mounts for the American Models side frames, which look fine to my eye and which would be cosmetic in this application. There are so many mechanical problems with the side frames that I think it’s best to just have them along for the ride.
The stumbling blocks? I have no experience doing CAD work – for etching, or anything else. I’m looking at courses, but in the meantime, Chris has been recruited. That said, Chris and I don’t know when we’ll tackle this project since there are so many other things to do – in the hobby and without. It could be years. Therefore, if anybody else reading this has experience designing photo-etched frets and wants to work with me on this project, I would love to hear from you!