Below are the guts of a Walthers Rotary Plow, their series 932-1950, and an end-on photo of the motor. It's apparent that a couple of the leads from what is likely a voltage regulator chip have been disconnected. The motor (with the retaining clip removed from over the top) is made by Mabuchi. There are no identifiers on it except for the manufacturer's name imprinted in the plastic header. The instruction sheet for these plows does not provide a part number. The shafts are 2mm in diameter and 10 and 11mm long. A search on eBay seems to identify this guy as one of their many class 130 motors, perhaps their "3v, 6v, 9v, 12v" job with a high end of 26,600 rpm. That would be a real whizzer and I suspect that's one of the functions of the regulator in this application. There is another curiosity here: a slow finger spin of the shaft reveals a "catch" or "drag" of the armature 6 times in a single revolution. I thought that a bit odd as I had expected either three or five. But I did note that Mabuchi makes some small 6 pole motors.
Question: can any of you conceive of any reasonable use for this motor in any repowering or other applications or is it a throwaway? (I can already hear gasps from some of you out there.)
BTW, the plug hanging out of the back of the shell evidently connects to pick-ups from a trailing tender. Can anyone steer me toward a supplier for male and female connectors of this size?
Obliged,
John
Mine works quite well hooked up to an old MDC sound decoder. If you don't like the motor, not hard to replace it with something else. But mine works fine as is.
Not sure about the plug, I'd probably just buy new mini-connectors from Walthers or Micro-Mark catalog and replace the exising plug with that. You will need a tender, the rotary only picks up power on one side and the tender on the other...plus, to be prototypical you need fuel and water for the steam powered rotary!
(Eventually I'll probably replace the decoder with a better one with "keep alive" as the rotary blades can stall and re-start due to the split pick-up.)
wjstix Mine works quite well hooked up to an old MDC sound decoder. If you don't like the motor, not hard to replace it with something else. But mine works fine as is.
RR_Mel I bought an Athearn Rotary and it was too long for a SP Rotary and had to shorten it. Mel
I bought an Athearn Rotary and it was too long for a SP Rotary and had to shorten it.
RR_Mel I usually pushed them with a Cab Forward. Mel
John:
Neat picture. The plow is obviously working hard.
I wonder why they are blowing the snow up the hill instead of into the river? It would seem to make more sense to let the river take the snow away instead of putting it where it might fall right back down the hill or cause future problems with erosion etc. Curious.
Dave
I'm just a dude with a bad back having a lot of fun with model trains, and finally building a layout!
hon30critter John: Neat picture. The plow is obviously working hard. I wonder why they are blowing the snow up the hill instead of into the river? It would seem to make more sense to let the river take the snow away instead of putting it where it might fall right back down the hill or cause future problems with erosion etc. Curious. Dave
Attuvian There is another curiosity here: a slow finger spin of the shaft reveals a "catch" or "drag" of the armature 6 times in a single revolution. I thought that a bit odd as I had expected either three or five. But I did note that Mabuchi makes some small 6 pole motors.
Regarding the motor itself, because of the way armatures move in and out of the two magnetic fields, a 3 pole motor will "cog" 6 times per revolution.
It will also have to overcome this tendancy to cog in order to spin in the first place. On a plow like this or any other constant speed application, its not a problem. I toss motors like this an a small box. It might come in handy for something. I wouldn't use it in a locomotive, as it would not likely allow super slow starting or creeping speeds. Some are worse than others though.
Five pole motors experience this cogging to a much lesser degree. And if the armature is "skew" wound, (windings and laminated core at an angle on the armature) that basically eliminates cogging. I've seen the magnets angled in a few cases to accomplish this. Either way the armature winding doesn't enter the magnetic field all at the same time.
Thus, even a good quality open frame motor can run smoothly and fairly efficiently. Better than a budget 3 pole can motor. Dan