Re-gearing N gauge steam locomotives

[roadrabbit]

Has anyone tried re-gearing the drive train on a steam loco?

With most RTR locos being able to run much faster than normal real life locomotives I was thinking that maybe slow speed running could be improved by fitting lower gearing. The motor would run at a higher speed for a given forward/reverse track speed, and would hopefully give a smoother drive.

I expect there is a very good reason why not, but I can't think of it myself.

[Bad Raven]

First post, so welcome, and the question's a LuLu!

Personal view, OK??

Take any N Steam Loco apart and you'll find there is little room to spare inside.

Most have Worm and Wheel gearing as a way of getting it as low geared as possible.

To alter even lower means a bigger wheel, resulting in a higher motor shaft dimension, probably not possible,

or

Finer pitch teeth, which reduces the strength and pushes accuracy tolerencing for production reliability into the no go area.

When you get to the bigger wheel locos, like the LMS 4-4-0 Compound, GF used a transfer gear which already has so few teeth on a tiny base that it is the achilles heel of the chassis.

The big breakthrough as far as GF design was concerned was the change from 3 pole to 5 pole, allowing smoother lower speed running with better power.

Its a big compromise, and foreign companies modelling their own areas of interest have locos with bigger boilers and cabs to play with.

Personally, I think the UK model manufacturers do a very good job considering the restraints!

[macwales]

Hi

I agree that retro fitting of higher gearing is problematic on some old locos - notably Farish Poole era. However

Dapol 9f
Dapol 2884 Class
Farish 3MT
Farish Austerity
Ixion (now Dapol) Hall
Dapol B1
are just a few in my collection of recent steam locos that will run and pull well at slow scale speed as will all my recent new Diesels.


All my Minitrix and my Farish Duchess will also perform reasonably well at about 20 mph scale speed.
Cheers

Mac