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MPC Dyn-O-Can


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#1 havlicek

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Posted 15 January 2017 - 08:01 PM

Another weird motor that's been kicking around that I finally got the time to dig into.  

I wound up replacing the ball point pen brush spring for a much sturdier spring from a period hop-up kit. Original was a high-count #30awg wind (like around 80 turns), so I dropped it one wire gauge to a #29 and junked the stack insulators. After all that, a comm cut and reassembly was all it took to have to spinning... much better.

IMG_1930_zpsdjdibgre.jpg

IMG_1931_zpsksm1snep.jpg
 
-john


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John Havlicek




#2 don.siegel

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Posted 16 January 2017 - 08:15 AM

Nice one, John - the hairspring is much more practical than the coil spring and little tabs used on the original (I've probably broken and/or lost about six of those trying to get that stupid spring in place!).

 

I assume you powder-coated the arm before winding? 

 

Good to see one of these, since I just left a comment in a thread on a mystery motor, which was a Dyn-O-Can... guess the brushes just run in the endbell, not on a fiber plate... 

 

Don 


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#3 havlicek

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Posted 16 January 2017 - 08:51 AM

Hi Don,

 

Certainly one of the less common motors from the "can era."

 

Yeah, it's hard to see in the photo, but the arm got powder-coated. The brush arms actually do run on/against a fiber plate on these motors (good eye!).  Instead of the plate being on top (outside) of the endbell plastic, it's underneath and not visible from the outside unless you're looking straight down/into the slot.

 

The big problem with the coil spring and tabs arrangement (aside from it being difficult to uninstall/reinstall) is that the spring exerts way too little pressure to keep the brushes in good contact with the comm. When I first reassembled the motor, it "topped-out" at something like 8-9v and wouldn't rev higher with more voltage applied. There was also a lot of visible arcing, even against a freshly-trued comm! Now it revs higher all the way to 12v and there's much less arcing. No doubt with some breaking-in, that will improve even more, as the brush faces on this motor seemed to indicate it had never been run... or at least much at all.

 

-john


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#4 havlicek

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Posted 16 January 2017 - 09:31 AM

BTW Don...

 

Thanks for filling-in the history here. I'm really weak on all that stuff, and it certainly does add some important pieces of information to what these old motors were about.

 

-john


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