What is the Purpose of two metel flywheels on eather side of a DC Motor in side of Model Locomotives? How would a Locomotive run without them? Allan.
The purpose of a flywheel is to store up energy with the intention to release the energy when needed. In other words, the spinning mass of the flywheels is used to carry the engine across poor areas of the track without any power required from the engine. It also helps the engine coast, which creates a bit of realism. The engine will operate fine without it but will stop much faster, and will have a tendency to stall more often on dirty areas of the track.
Jim
it smooths out the running beacause once the motor starts running the momentem provided by the flywheel(s) would keep the motor spinning longer if the power was cut so if the motor runs a little uneven the flywheel helps smooth it out. I’ve owned engines w/o flywheels and trust me flywheel(s) make a huge difference.
The flywheels are there to help the engine coast past spots where it loses electrical connectivity. They’re especially helpfull at low speeds, where the medol just doesn’t have enough momentum on its own. They let the mechanism coast, so that the wheels continue to be driven.
I don’t know about in other scales, but I’ve found that in N scale, engines without flywheels, simply can’t be run at low speed. They’ll stall at the drop of a hat.
As “soo line fan” said, to simulate momentum and get the locomotive to operate better on dirty track.
Depends on the locomotive. On stopping, they acutally turn the motor into a generator and force electricity backwards into command control decoders. In this reguard they aren’t good. Theoretically, with DCC they should not be needed for the momentum as the decoder can simulate that better than fly wheels ever could. The new Lenz gold series decoders that don’t have to have electrical contact (USP) with the track to work right should eliminate the need to have them for dirty track. That would leave a lot more space in the hood for electronics and speakers.
Athearn made engines for years with flywheels and without! They were ahead of their time with the flywheels back in the late 1960’s. They used steel which has been replaced by brass now. Brass carries more weight in a smaller area. I own some of the older Athearns that did not have flywheels, they run fine, but if you have a small spot of track or frog that has a dead spot in it. The nonflywheeled loco will find it and could stall or shutter for a second. With Flywheels, you have more bottom end power, wich stays constant, bottom line is flywheels create more force, so the motor does not have to work so hard.
Yep, the flywheels are for momentum.
Ever work on a Standard or auto tranny auto? They use flywheels also. The teeth are for the starter to spin. The weight ofthe fly wheel assembly provides the momentum to keep the crankshaft and all that is connected to it moving between the power strokes of the pistons. That is why if you have a car that is misfiring, it will still run, but roughly.
Flywheel locos are the same principal. Use momentum to keep from stalling from minor electrical pickup problems that would stall a non fly wheel locomotive.
To expand on what Ralph Grassi has said regarding the power strokes of an automobile engine, the old open-frame motors were usually five pole motors that were not skew wound. This meant that these were essentially five piston engines. The flywheel smoothed out torque peaks of these motors. I have an Athearn two motor DD40 and a Bowser T-1. Whenever I assembled these engines, I always made a point of lining up the pole of one armature against the slot on the other engine. This gave me an essentially 10-pole motor that did not need a flywheel to operatre smoothly at low RPMs.
I have an Athearn RDC that doesn’t have flywheels. It doesn’t run too bad…but it could be much better. As is, it stops on a dime, and doesn’t run very well at slow speeds. Maybe I’ll add flywheels the next time it’s in the “shop.”
Thank you guys for the Great info on this topic. I now understand. By the way…
I totaly forgot about this topic was even here,oops. LOL.
Another VERY important purpose everyone has managed to leave out is the vibration dampening effect that the flywheels have. Much like that of a harmonic balancer on an internal combustion engine, the flywheels smooth out the pulses of the armature passing by the stator. While this may not be very noticable at high speeds, removing the flywheels would dramatically affect low speed operation. It would likely become much more jerky.
How well the flywheels help the smoothness and coasting also depends on the size of the flywheels, the jerkyness of the motor and the stiffness of the motor. I have a Walthers GP9M with a flywheel that’s so small it might as well not even be there. It barely helps th engine coast and the motor and mechanism are just as smooth without it.