Model Train Journal

I have sometimes wondered that some steam have die cast center to the drive wheels while others have coined brass. Did a search on Google and AI yielded this answer: “ Coined brass O scale wheels are specialized, die-struck or "coined" metal wheelsets used in 1:48 model railroading. The coining process stamps the brass under extreme pressure to create highly accurate, detailed locomotive drivers and rolling stock wheel contours, avoiding the slight porosity of cast alternatives.”

An additional description was this: “ Unlike die-cast or nickel-silver, solid brass wheels offer excellent electrical conductivity, making them ideal for two-rail DC/DCC power routing and grounding.”

Never really thought there was much of a difference between die cast and coined brass drivers. Apparently there are some real benefits of coined brass drivers at least in detail. Not so sure about running performance.

The third category - cast iron - is quite good at traction, adequate for electrical conductivity, and in my opinion, more attractive than the coined variety. The only die cast in 2-rail scale that I know of is All Nation and Thomas. Almost all imports have coined drivers, and nickel silver has only been used by Ed Alexander to my knowledge. I have no problems with conductivity on any metal drivers.

Bob,
I appreciate your wisdom on my query. After all my Scale Craft and Lobaugh pieces run fine and lack coined brass drivers. Hard to argue with years of running and experience.
Rob

Many of the imported HO steamers from Japan in the early mid 50's had coined drivers ...

see link for a Tetsudo NYC Niagara with the coined drivers warning it is HO for those of you with a weak heart

https://youtu.be/S-crlz5DYc4?si=dUhIimUQgSRN2rJQ


cheers Carey

Weak heart here - I will look later.

On the cast iron drivers - this locomotive has two drivers with the tire machined into the cast iron, and the insulated drivers are wearing tires machined from cast iron pipe (used by plumbers in really big jobs). The axles are rigid, as in "unsprung." When one driver lifts off the rails there are only three making contact, so you can assume that's all there ever are, doing the pulling.

Granted, those are giant drivers (84" in regular O scale), so maybe the footprint is infinitesimally larger than, say, for a 57" driver. But this little gem pulled ten Kasiner/Mac Shops cars, each with 3/4" lumber inserts both for floorboards and roof area, and each with sand cast trucks and steel wheels, without missing a beat. 8424 motor, NWSL Mod 0.5 non-idler gearbox.



In short, if you want traction, use cast iron. Do not worry about equalization or springing - traction seems to go up as the weight goes up, so as long as at least three drivers are pulling you should get almost identical performance as you would from a fully equalized engine bed.

An aside - well over half my scratchbuilts have provision for full driver springing.

I know at least the early MG loco used brass wheels that were plated, but at the drivers brass or ????