Hello all,
I’m about to re-motor my Akane Yellowstone 2-8-8-4 and i have a question. I’ve read (some time ago) that a few modelers prefer not to use flywheels when installing new motors. It’s a NWSL 20-32D9 that I’m going to install. I’m just wondering that with the increased mass of a brass loco, wouldn’t it be wise to use a flywheel? But it is a NWSL motor and have heard that these well built motors (among the best, i think) don’t benefit from a flywheel. Help me solve this conundrum!
Stephan
I don’t ever recall doing a re-motoring job where a flywheel was used: if the loco had one (or two) originally, it was neither re-used, nor replaced. In most cases, I opted for extra weight. This applies to both steam and diesels. In fact, my Proto USRA 0-8-0, which came equipped with a flywheel, ran very nicely but was barely able to move its own shadow around. I removed the flywheel, replacing it with a block of lead (along with some more weight elsewhere) and she runs just as well as before, but can also pull a decent string of cars. If the gearing in your loco is decent (Akanes are built like tanks) and there are no binds in the mechanism, I doubt that a flywheel would be of any benefit.
I’m not sure who made the one shown below, but even without the benefit of the weight of the boiler/cab assembly or a flywheel, she crawled through turnouts and around tight curves without hesitation.
I had only the mechanism on hand (to repair the frame) but would have attempted to correct the drive shaft alignment had her owner also sent the boiler. [swg]
Wayne
I like using flywheels just for that extra bit of coasting they add, but they’re really not necessary if you’ve got a good mechanism. Before advanced electronics came around and all wheel electrical pickup wasn’t so common, flywheels would add more momentum to add a bit of realism, and they would help to coast through dirty track (which was brass or steel before nickel-silver, both of which form unconductive tarnish). Steam and diesel engines are so well engineered these days that flywheels are more of a marketing tool than anything.
I’m with Darth Santa Fe - I personally prefer flywheels. I like the coasting action and I prefer not to see the locomotive slammed to a stop by the locked worm.
That said, if your model runs slow enough to suit you with the motor reasonably above its minimum RPM, then a flywheel is not essential. To me, that’s the key - getting the model to run slow enough without the motor being right at its minimum RPM - and without being noisy at a prototypical top speed.
In larger models like your Akane Yellowstone, a flywheel would be personal preference. You are not likely to use the engine for very low speed switching moves. And the new motor is likely to deliver slower speeds throughout the range when compared to the old open frame.
In smaller models like my 0-4-0Ts and 2-4-2Ts, getting smooth running at real switching speeds is more of a challenge. If the motor is running at minimum RPM, the slightest current interruption or change in electrical resistance can make the motion jerky. The electrical issue is real because of the limited number of wheels to pick up from. In that situation, the flywheel helps smooth things out.
my thoughts, your choices
Fred W