How Can You Build A Locomotive Chassis?

Jollybob · July 20, 2018, 01:49:36 PM

Hi all, how easy is it to make a chassis for a locomotive? With there being plenty of spare bodies readily available to experiment with plus the use of 3d printing, there are so many possibilities. I would really like to have a go at building a locomotive chassis and wiring it up to a motor but I don't know where to start?
Has anyone else ever had a go at this?

Rob.

Snowwolflair · July 20, 2018, 02:14:18 PM

Building locomotive chassis are relatively straight forward, but making ones that work well is very difficult. The difference is the accuracy of cutting and drilling holes etc otherwise you get gears that do not mesh and wheel sets that don't sit evenly and rock.

A good start on how to go about it are the 2mm society locomotive building guides. They are a different size/gauge but the principles are the same. They also do some nice tools for setting up gears etc.

Another way to achieve custom chassis is to butcher existing chassis, and if you look at my thread on building two Beyer-Garrett locos using Fairburn Tank locomotives you will see an example of this.

However, having the correct tools are essential. The three tools I find are invaluable are a pillar drill, a mill and a bed fret saw, and in my case I have a preference for Proxon tools. These allow me to drill at right angles, mill parallel and flat faces and to accurately cut brass sheet.

thebrighton · July 20, 2018, 03:36:10 PM

One option is to look at chassis already available and see if any match the wheelbase you require and whether the correct size wheels are available from another chassis then you can mix and match. Switching the motor for a smaller one can also open up more possibilities. You can also just dump valve gear to give a different appearance or conversely add valve gear from another chassis. Look out for spare and repair locos on Ebay etc and have a play around. A few relatively simple conversions are below.

First up is the chassis for my SECR C Class. It uses Farish 4F wheels and chassis with everything removed. Parts of an NBrass tender to loco drive kit were used along with a Nigel Lawton midi motor. It looks and is a bit of a hotch potch but works very well.

Next up is my Aeolus class. It's a Farish GP chassis with all the motor elements removed, a Nigel Lawton motor and Farish outside frame 08 wheels.

Just as a final example this is a Farish 3MT chassis with valve gear removed, turned back to front and a Farish bogie added for my J class chassis.

You can come up with loads of combinations without actually having to build from scratch as getting holes for gears and wheels in the right place can be tricky and if only a fraction out will result in poor running.
Have a look at what's about.

Jollybob · July 20, 2018, 10:18:11 PM

Thanks guys, the information you provided has been really influential.
I really want to see if I can make a 2-4-0 chassis for a tank engine and modify a farish GP body.

Rob.

Jim Martin · July 24, 2018, 10:50:47 PM

Quote from: thebrighton on July 20, 2018, 03:36:10 PM
Just as a final example this is a Farish 3MT chassis with valve gear removed, turned back to front and a Farish bogie added for my J class chassis.

Is this a work in progress, or is it a completed model? I've seen photos of many of your models but I don't remember this one.

Jim

thebrighton · July 25, 2018, 11:15:50 AM

Quote from: Jim Martin on July 24, 2018, 10:50:47 PM
Is this a work in progress, or is it a completed model? I've seen photos of many of your models but I don't remember this one.

I finished it a little while ago, it's towards the bottom of here http://www.ngaugeforum.co.uk/SMFN/index.php?topic=18674.150

Jim Martin · July 28, 2018, 10:54:11 AM

Quote from: thebrighton on July 25, 2018, 11:15:50 AM
Quote from: Jim Martin on July 24, 2018, 10:50:47 PM
Is this a work in progress, or is it a completed model? I've seen photos of many of your models but I don't remember this one.

I finished it a little while ago, it's towards the bottom of here http://www.ngaugeforum.co.uk/SMFN/index.php?topic=18674.150

Thanks! That's another lovely-looking locomotive!

Jim Martin · July 28, 2018, 01:25:52 PM

Is there a list anywhere of the wheelbases and wheel diameters of RTR loco chassis? I'm thinking of the actual dimensions, not the dimensions of the prototypes that models are supposed to represent. I vaguely recall seeing such a thing several years ago, but I don't know where and I could just be wrong.

Jim