-Ability to ditch the rubber tires and go with smooth wheels, if desired. I despise rubber tires. Unfortunately, almost NO locos in 3-rail offer a convenient way to get rid of them without leaving empty grooves in the wheels. Let's make this happen NOW!!
-Ability to easily change gear ratios. I.e., a separate gearbox, rather than one cast into the chassis. An added benefit is that wheels and axles may be replaced as a unit, without re-quartering, or resorting to a puller and a press. (Of course this request presumes that spare parts would be available.) Sunset 3rd Rail uses a separate gearbox, and also a belt-and-pulley system, which facilitates changing the ratio, if desired. But it would be nice to see this quality mechanical design in traditionally-sized trains.
-Ability to easily swap/replace motors. This implies that the worm gear or pinion gear is NOT pressed onto the motor shaft. Also, that the flywheel is put on with a set screw, and not pressed on. (Some better locos are already built this way, but most traditionally-sized ones aren't.)
-Consistent and unrestricted parts availability. Find a good design, standardize on it, and stock enough parts for kitbashing, scratchbuilding, etc.
-Plastic tenders with a metal frame. Die-cast tenders are DUMB. It's ALWAYS possible to add weight on or below the frame. Direct or battery R/C is just around the corner, and you can't get a signal inside of a metal tender shell. Insulated handrails are a fragile point of failure, and all that circuitry doesn't belong in the boiler where it hinders maintenance of the gear train. No!! If I have to cast facsimile tender shells out of resin for my upgrades, then I'll do it!
-Better quality control, especially with regard to the quality of zinc castings (i.e., no zinc pest)!
IMO the perfect loco hasn't been built yet. Especially with the traditional-sized trains, manufacturers are still cutting corners and there's a lot of room for improvement. Good thread!
