MTH announced Premier 3-Truck and 4-Truck Shays with matching log car sets - Terrific

Will the chuffs be synchronized with the motion of the pistons?  This has been a sore point on many O scale shays.  The MTH page says synchronized, but with what?

@th55 posted:

Will the chuffs be synchronized with the motion of the pistons?  This has been a sore point on many O scale shays.  The MTH page says synchronized, but with what?

Well, knowing MTH PS3 electronics use the tachometer flywheel on the motor for both speed control and chuff interval timing based on a count, technically no different than any other PS3 engine.

So no, it's not a chuff cam and that cam being exactly sequenced to the valves of the cylinders.

That said, it would be the correct rate, and speed.

Are these able to be run on O-54 curves? The listing says O-72, but previous versions and one that I have either say O-42 or O-54.

My logging layout is O-54+ and I wanted to make sure these could run on my curves.

We have the first run MTH shay from 1997 (20-3023-1) and right on the end cap label it says it will run on O-42. I'm not sure what changes have been made since then to require O-72 but I'm in if can run on O-54 also.

I suppose that MTH will have to clarify to be sure, but I wonder if it's a difference between the 3 truck and the 4 truck versions.

@H1000 posted:

We have the first run MTH shay from 1997 (20-3023-1) and right on the end cap label it says it will run on O-42.

Thanks H, I doubt this is newer tooling and if your 4 truck shay can handle O-42 and wider, I’d hope the 3 truck could as well.