Help scaling live steam design up

I want to build the Virginia designed by LSBC, but I want it 4-3/4" gauge, not 3-1/2". what adjustments should I make to the design to make sure it performs as expected?

Welcome to the forum Jared,

As its only about a 50% increase in size, most things will be fine, but you may be able to make a few parts less bulky to improve their appearance.

The main issue will be the boiler, it will be worth speaking to the person who will test your boiler (I assume you are in the States or Canada?) to agree the design. It may be possible to use a more modern 4 3/4" boiler design for a similar engine.

Alternatively David Piddington's design for Washington in 5" gauge is well thought of and you could possibly get by with just regauging, and moving the cylinders, motion and brakes in by 1/8" each side?

Neil

Hello Jared,

Following on from Neil's reply a quick treddle on the calculator shows 3/4" scale to 1"scale to be an increase of some 33.33% The scale would be in the order of .084" = 1"

If you follow the old LBSC drawings in respect to the chassis, cylinders and motion you should not be far out, many have been built in the smaller scale an all seem to perform alright; in your case the boiler is the main issue and as Neil has said speak to somone in you local society before going too far with the boiler.

Regards,

Bob

Thanks a lot guys. I really appreciate your taking the time to help me out. I'm an American (US) living in El Salvador, Central America, so I'm kinda on my own.

I just looked up the Washington, and yes! I think it's exactly what I was looking for. Plans come with instructions for both 5" and 4-3/4" gauge

I think I can get many of the parts machined here locally much cheaper than you could in other parts of the world, but I'll have to see if I can find someone that can do precision work for me, that may be the challenge. If not, it looks like Reeves will cast them for me. I'll try making them here and see how it goes.

This will be my first model train, but I'm a very quick learner, and I have the patience to keep with it. I'm expecting this to take several years.