Would this work if powered by dc?
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Märklin essentially did what you propose with their High-Efficiency Motor Conversion Set.
Märklin motors in the past were universal motors very similar in construction to Lionel's Pullmor. Märklin offered conversion sets which replaced the electromagnet field with a permanent magnet field.
https://cdn.shopify.com/s/file...rklin-60941.pdf?2136
In principal, should work fine.
What you've actually done is made a an open frame can motor. 
I think the mechanical aspects of the replacement would be the sticking factor. I wonder if the new motor would work with back-EMF cruise?
GRJ, now that sounds exiting too me. An original Lionel motor with the smoothness of a can motor that can easily be repaired when needed.
You are still stuck with the three poles. I believe the Pittmans we are accustomed to are 7 or 9 pole varieties which adds much more to the smoothness than a permanent vs electric field magnet.
I'm not sure of the steps to take but I've purchased stuff direct from Chinese manufacturers before (those wrist bands you sell for small lot profit generating schemes). The manufacturers were aggressive in their response to get business.
I'm wondering actually about contacting a Chinese based motor manufacturer about cooking something up like this...with the addition of a 5 or 7 pole armature as part of the spec.
I'm sure all they need is a pullmor to back engineer the form factor and could easily generate a motor.
This could potentially be a drop in all the way to the control circuit.
Maybe a kickstarter project...hmmm...
It might be easier to find a can motor that will fit in the space previously occupied by the armature.
@romiller49 posted:GRJ, now that sounds exiting too me. An original Lionel motor with the smoothness of a can motor that can easily be repaired when needed.
Like Bob says, it's the number of poles that would dictate the smoothness. I truthfully don't even know how well the back-EMF cruise would work on a 3-pole motor.
Honestly if you stuck a 5 or 7 pole armature in a bog standard Pullmor motor it would have much better low speed performance, even without cruise. You notice a huge difference at low speed.
@Lou1985 posted:Honestly if you stuck a 5 or 7 pole armature in a bog standard Pullmor motor it would have much better low speed performance, even without cruise. You notice a huge difference at low speed.
If only you could find one that would fit.
A way to smooth out operation from a three pole armature is to have more favorable gear ratios. Universal "Pullmor" motors are typically geared 8:1 (eight revolutions of the armature to one wheel revolution). Changing the gear ratio to 12:1 or 16:1 would greatly smooth out low end operation and reduce cogging.
However, top end speed would also be reduced.
There are some threads on the forum where one took a 2028 motor/truck and changed the gear ratio. While changing the gear ratio would be a lot of work it may be more accomplishable than changing the number of poles on the armature.
@WBC posted:There are some threads on the forum where one took a 2028 motor/truck and changed the gear ratio. While changing the gear ratio would be a lot of work it may be more accomplishable than changing the number of poles on the armature.
If you're going to that much trouble, lose the Pulmore and install a Pittman motor, these issues will be a thing of the past.
@gunrunnerjohn posted:If you're going to that much trouble, lose the Pulmore and install a Pittman motor, these issues will be a thing of the past.
Just trying to stay within the spirit of the OP thread while also pointing out that the gear ratio also greatly impacts the smoothness of low speed operation.
