I wonder if any of you have decided that flywheels don’t offer enough benefit to mess with. I have been contemplating using mashima/kato motors (in one case) and the ubiquitous athearn gold motors or atlas/roco (from 70s GP-38/40 SD-24-35) motors (in the second case), and thinking control systems are advanced enough that the problems flywheels were employed to solve are no longer an issue, or can be better solved through other means. BTW, I plan to use either straight DC or dead rail, no DCC.
All motors need inertia to help smooth out their mechanical operation, inertia is very important to make a motor run smoothly. With the new rare earth magnets the can motor manufacturers use less mass in the rotor and that makes a flywheel even more important.
Per DC systems, everything I have ever read or experienced, a flywheel is a worthwhile addition. Cannot image any type of DC power pack which would change that.
The Roco, Mashima and Kato motors you mentioned, while 3 of the best, still need a flywheel to help with coasting and momentum.
I regularly remove one flywheel when doing sound installations in smaller engines like switchers. It gives the much needed room for a speaker and I’ve noticed no discernable difference in performance.
I’ve yet to completely remove both of them even though I’ve heard from a couple sources that they are no longer needed with todays decoders … not sure about that myself.
Now - if I were to add a keep alive module, I’d have no hesitation to remove them both. Kind of a catch 22 kind of thing though … remove the second flywheel to make room for the keep alive module so you don’t need the second flywheel !
With DCC, you can adjust various CVs and get performance that simulates what a flywheel does – but it would perform still better with an actual flywheel.
With DC, I know there are some high quality systems out there, but don’t believe I’ve heard it said they replace the benefits of a flywheel. Even if there are ones able to simulate smooth action like you can often get by fiddling with CVs in DCC, I would imagine they, too, would still perform better with a flywheel than without.
It’s hard to replace the obvious benefits of spinning mass no matter how “smart” your power supply may be.
I was doing a bit of research on this back some time ago…the idea of an electronic flywheel. The use of a bipolar arrangement of capacitors with diodes in parallel, looked like it had some possibilties. I didn’t test out what I found, though. So I can’t say how well it works or not.
While I agree setting CVs would do basically same job as the flywheel I would still not remove it…
I base that on my thoughts I would hate to see my locomotive stop at a speck of dirt on the track like in the old days when my Brass diesels would stall on dirty track faster then my flywheel equip Hobbytown RS3.
While I agree setting CVs would do basically same job as the flywheel I would still not remove it…
I base that on my thoughts I would hate to see my locomotive stop at a speck of dirt on the track like in the old days when my Brass diesels would stall on dirty track faster then my flywheel equip Hobbytown RS3.
Exactly, and to add that the mass of flywheels help to dampen, any imbalance/ vibrations within a drivetrain. Even a “perfect” driveline can generate harmonic vibration that is quelled by the mass of the flywheel. This can be from brush vibration, gears or the universals themselves.
I run flywheel free on DC, and use dead rail to stop trains in ‘fire and forget’ mode. An abrupt dead rail stop from track speed is a good way to find weak couplers, especially on the first few cars of a heavy train running downgrade. If you have truck mounted couplers it’s also a good way to pop a light car over the railhead and onto the ties.
On the other hand, I want the train to stop where I want it to stop, not coast half a meter down the track to foul a switch (or worse.)
Chuck (Modeling Central Japan in September, 1964 - analog DC, MZL system)
The only flywheels of any consequence with which I’m familiar are those in the old Model Power E-units, and they turned those locos into great performers.My Bachmann locos all seem to have flywheels and they run fine - hard to say if the flywheels contribute much to that, though, as their diameter and mass isn’t all that great.
The couple of Atlas diesels I have left also have flywheels and while they’re very smooth runners, I have a couple of Blue Box geeps which I re-motored, and at the same time removed their flywheels and they run better than the Atlas. My homemade doodlebug is also a good performer, with a can motor and no flywheels, as were my twin-motored U-boats, with the flywheels removed in favour of more weight.
I had a Proto USRA 0-8-0 which was a very smooth runner but pretty-well useless as far as pulling. I was going to get rid of it, but took it apart to see if there was any place to add some weight. After removing some extraneous wiring and a circuit board, I also lopped off the flywheel - I think its diameter was even smaller than that of the motor’s armature - then managed to add several ounces of lead in the newly found spaces. It runs just as well as with the flywheel, but can now pull a decent-size train, too.
In most cases, I doubt that the flywheel causes any harm, but from my experiences, I doubt that removing them does either.
A couple of thoughts about what you’ve found. Flywheels usually are balanced and it’s easier to get two small flywheels running smoothly than one big one. Plus the typical diesel chassis make it’s easier to apply two smaller flywheels than a single big one.
A little flywheel does a lot. Adding more flywheels or more weight to it brings diminishing returns past a certain point as far as drivetrain dynamics, but as you noted there are ways to at least partially compensate for removing it. As far as providing weight on the driver’s, more is generally good, so if the weight can be made up elsewhere then removal is not so bad in that regard, either.
Steam locos typically use a single flywheel, as big as possible. The typical steam driveline doesn’t offer an easy option for two flywheels, but they seem to do OK. I suspect having a flywheel on steam is a bigger benefit than on Diesel because it helps keep the valve gear and rods turning smoothly, an issue most diesels don’t have.
Flywheels have the advantage of letting a locomotive roll over a bad spot in the track, either dirt or the frogs of certain turnouts, an advantage a momentum throttle can’t help, since you still need good track to loco electrical flow.
The effect of flywheels is largely overrated when it comes to the ability of coasting in case of a power shut-off, but they do help to overcome spots of dead rail. On my layout, a 0-4-0 loco without a flywheel would not traverse through the Insulfrog turnouts I have installed, but the flywheel equipped locos have no problem at all, even at low speeds.
Don’t forget that flywheels add a considerable amount of weight to your loco; removing them will make your loco lighter and also reduce its tractive effort.
In my old and feeble brain a flywheel is far more advantageous than simply the momentum they provide. They smooth out the power delivered to the wheels and keep slow speeds much more realistic. Once they became somewhat standard on diesels I think everyone saw the potential advantage of flywheels for every locomotive. They also add weight to the loco, increasing the locos footing and pulling power. Keep Alives, Power extenders and Power Pack type electronic energy storage devices are great additional devices to improve performance. But, I hope that flywheels will solder on!
The traditional advantages that flywheels offer still exist, plus a few of the advantages some mentioned like extra weight. Sure seems the common sense approach would be to keep flywheels.