Regular readers know I’m unhappy with the six-wheel trucks under my passenger cars. They look fine, but they do not track reliably. Earlier this month, I wrote about how I would love to modify these trucks with a subframe to provide rigid beam compensation on the axles.
Well, my friend – the very talented Tim Warris at Fast Tracks – visited last week and he was intrigued by the problem. Tim went home with a set of wheels and a pair of stock American Models passenger trucks, and over the weekend he drew up, then laser cut and assembled, a solution:
As Tim writes on the Fast Tracks Facebook page,
Took a break from trackwork designs this past weekend and designed this set of S scale equalized 6 wheel trucks for Trevor Marshall’s Port Rowan layout. While custom projects such as this aren’t something Fast Tracks typically does, we made an exception as this seemed like an interesting quick project. The entire assembly is laser cut from plywood, the same wood we use for our QuickSticks. This is a sub-assembly that will have cast sideframes added to it when installed onto the passenger cars they are designed for. While it’s kind of hard to see in the image, two of the three wheelsets are able to rock and twist within the side frame, allowing for very smooth operation over uneven track. These should go a long way to eliminating some operational issues Trevor was having with the poorly designed trucks available in S scale. There is no limit to what can be done with a laser cutter and some imagination!
Tim has posted a video to YouTube showing the trucks smoothly navigating an uneven surface. The two floating axles rise, fall and twist as needed to keep all six wheels in contact with the surface at all times. The threaded rod and trapped nuts make for a very smooth pivot, and the wood construction means there’s no need to insulate the wheel sets from the subframe:
I wondered about the choice of wood, but Tim reassured me: “Wood will outlast almost any other material,” he reports. “Hydro electric dams installed wood bearings 100+ years ago and are still using them, very durable, won’t cause any issues.” That’s good enough for me.
Tim is going to cut a few more sets of these for me so I can retrofit my three passenger cars. We compared schedules and as he notes, trying to find a time when we can get together in the next week or two turned out to be more difficult than designing the trucks, so he’ll pop them in the mail. I’m already standing by the mailbox…
Thanks for this, Tim. I feel like a kid in the days before Christmas – waiting to open my presents. I’m looking forward to putting side frames on these, slipping them under my passenger cars, and saying goodbye to bad running!
UPDATE (JUNE 22, 2015): Tim now offers these on his web site. Having had them in use on my layout for about 18 months now, I’ve written up some construction and operation notes on these to help others decide whether they want to try them.