differences in can motors

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gregc

Apprentice Modeler
#1
are all can motors of the same size basically the same, or are some manufacturers better than others?

how does the number of poles affect motor performance?

and why not use lead (11.3 g/cm^3) for flywheels instead of brass (8.5), or better yet, tungsten (19.2)?
 
#2
are all can motors of the same size basically the same, or are some manufacturers better than others?

how does the number of poles affect motor performance?

and why not use lead (11.3 g/cm^3) for flywheels instead of brass (8.5), or better yet, tungsten (19.2)?
Yes there are differences between the motors. The best one's I worked with are by canon, but I'm sure there are others just as good. The differences are typically in torque, current draw, starting voltage and even the quality and strength of magnets used. Some are also much quieter than others.
As far as the number of poles I usually compare it to car engines. The difference between a 4 and 6 cylinder engine at the same size is typically how smooth they run. Same with a 5 pole motor. They offer great torque and run much smoother since there are 5 power points vs 3.
 

kbkchooch

"retired" conductor
#3
and why not use lead (11.3 g/cm^3) for flywheels instead of brass (8.5), or better yet, tungsten (19.2)?
ITs a trade off. Lead is too soft, Tungsten is too hard on the lathe trueing process. Brass is stable, hard enough, and yet easily trueable on a lathe without ruining tools.

Oh, and I'd stay away from "coreless" motors if you are considering DCC. If an engine without a decoder, or a faulty decoder, comes in contact with DCC its "zappo-poof" for that motor.
 

Espeefan

Well-Known Member
#4
Take a look at the spec sheet for the motor. That will usually tell you what you want (and need) to know. In addition to that which has already been stated there are differences in RPM, from around 9000-16000 rpm depending on size and in some cases vintage (motors bought at swap meets, old "new" stock). 5 pole skew wound motors are made for smooth starts and smooth low speed operation. Older 3 pole motors are less efficient, and some are wound for high speed, so don't get tempted by cheaply priced motors for RC cars and so forth :D. If you stick with NWSL, Sagami (out of business but still lots around) Mashima, Buehler (sp?) and Canon you should be OK. If you're re-motoring older brass steamers you might have another task after the new motor is in.
 
#5
With 5 pole skew wound motors and all wheel electrical pickup the flywheel isn't really necessary.



A Roundhouse chassis modified to put on an IHC 4-4-0 boiler



I have run the Athearn/Roundhouse 4-4-0 with and without the flywheel. The performance is the same.

Harold
 

Espeefan

Well-Known Member
#6
I disagree. If you have auxillary power pickups on the tender, you are probably ok, but if you don't, and depending on the model, a flywheel will smooth out operation and get you through turnouts with insulated frogs or spotty trackwork. I fit them if there is room in the model. They also add weight which is never a bad thing with steam locos.
 
#7
Yes, the flywheels make for smoother starts and stops. If the flywheel is unnecessary, then no one would put them in models anymore.

I have an IHC Premier (Mehano) GG1 and it comes with two motors and a flywheel on each. The flywheels aren't big enough so they do nothing. The engine starts abruptly when starting, and stops abruptly when stopping. The flywheels DO make a difference.
 
#8
Yes, the flywheels make for smoother starts and stops. If the flywheel is unnecessary, then no one would put them in models anymore.

I have an IHC Premier (Mehano) GG1 and it comes with two motors and a flywheel on each. The flywheels aren't big enough so they do nothing. The engine starts abruptly when starting, and stops abruptly when stopping. The flywheels DO make a difference.
Does the motor have five or more poles. If not that is why it performs poorly. The motors are crap.

Harold
 

Espeefan

Well-Known Member
#9
There have been no three pole motors used in quality models for many years. The last one I saw was an old Rivarossi some 15 years back. I can see why your 4-4-0 shows no difference in performance. The motor mounting does not allow enough room for one large enough to be effective. Bachmann's new Peter Witt trolleys are the same way. They put flywheels in them, but they are too small to be effective. OTOH, I do have models where you can see the difference when flywheels are added. You can't buy a quality diesel model from anyone that does not have them these days
 

Espeefan

Well-Known Member
#11
Does the tender pick up power from both rails? There are four wires that I can see coming out of the rear of the loco chassis.
 
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#12
It originally picked up on two of the drivers and all of the tender wheels. The crappy MRC sound unit died and I used a Tsunami setup with only all tender pickup and it still ran great.

Harold
 

Espeefan

Well-Known Member
#13
Thought so. That's why you do well over dead frog turnouts. Some older steam models pick up from the loco on the right and tender on the left. Short wheel base models have trouble over dead frog turnouts and insulated crossovers. Your model's lack of benefit from the flywheel is likely due to the improved tender pickup and the lack of room for an adequately sized flywheel. So for your model, point taken ;). In general though, flywheels do help. The first time I ran my early run ALCO PAs, I ran them into a siding and cut the power. The flywheels spun for so long that the locos coasted into the next block, powered back up, and kept right on going. They would not have done that without the flywheels. That is an extreme case, but it shows that they do have an effect on how our models run!
 

Espeefan

Well-Known Member
#15
Better pickup is what makes the newer locos better not the flywheels.

Harold
Well Harold, if we're talking about your 4-4-0, I think I've already agreed with you. As for everyone else's models, I don't believe so. Take my PA's for example. They had all wheel pickup, and perform better with the flywheels than without. I have lots of brass steamers that benefit from flywheels installed, and some that don't due to insufficient room for an effective one. Tender pickups do definitely help, and I have them on my short wheelbase locos, like the 2-6-0's and the 4-4-2's.

This is all a matter of preference, of course, and to each his own, but I would be reluctant to use the words "never" and "always" in a sentence about anything in this hobby.

If however,you can prove across a broad spectrum of models that flywheels don't help, I'd suggest you contact Athearn, Atlas, Walthers, Bachman, BLI, MTH, Rivarossi, Stewart Hobbies, Overland, Sunset, Glacier Park, and the rest, and let them know that they're wasting a ton of money putting flywheels in almost everything they make. Or maybe they know something you don't ;)
 
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#16
My question about these can motors is. Is there a source of these motors that doesnt cost 30 or 40 bucks apeice? I would think these motors are being made for another type of application and just happen to work well for modeling purposes.
 

kbkchooch

"retired" conductor
#18
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