Jump to content




Photo

Drag motors


  • Please log in to reply
12 replies to this topic

#1 havlicek

havlicek

    OCD Rewinder

  • Subscriber
  • PipPipPipPipPipPipPipPip
  • 10,288 posts
  • Joined: 20-August 07
  • Gender:Male
  • Location:NY

Posted 10 December 2017 - 07:17 AM

     All this stuff about drag motors got me thinking...a dangerous thing.  While building-up the drag motor for Tom, I found some pieces for another that I set aside to build another one for laughs.  This all got me to two possible directions.

     First one is from a generic FT36D that I got somewhere and came with an installed can bearing.  In the past, these things have failed on me, so whenever I get one I get rid of the bearing as being less desirable than the stock Mabuchi rotating bushing.  So I dug around and took the large oilite from an industrial Mabuchi round can 36XX sized motor.  These bushings are oversized for what's left of the Mabuchi bushing carrier after removing it's innards, so it got turned-down to fit (*with a taper to fit the ridged pocket).  The same industrial Mabuchi comes with a set of very strong ceramics that are a close-to-perfect fit for the FT36D can, although a bit tall.  Grinding off around .035" from the top and bottom of each magnet to fit the can also thins out the thick tips of the magnets.  So as much as I hate grinding magnets, it does some good things beyond just getting them to fit.  These magnets are shorter than the Mabuchis or the Champion Arcos, but considering the magnets are one of the two biggest contributors to the weight of an FT36D, a lighter magnet that's as strong or stronger than Arcos is probably a good thing.  The other major contributor to the FT36D motor's weight is of course that big ol' thick-web-and-crown armature...BUT...a shorter pair of magnets means a shorter stack as well, so I made one up to fit. 

 

     Going on a diet should help this motor to spin-up faster, and a shorter stack should shift the torque-vs-RPM equation a little in favor of RPMs.  No doubt the motor will still have plenty of "OOMPH" in any case.

     The last little bit I decided to take care of was to get rid of the extra hunk of brass on the outside of the can, figuring these things can often go full-sidewinder, so the slight shortening of the overall motor's length might be a help.  Leaving the grooved portion of the bushing carrier means mounting can-drive is in no way affected...so why not?  Mounting the can in the mill, the deed was done.

IMG_2377.JPG IMG_2378.JPG

     The second opportunity for a possible build that caught my eye was for a 26D.  Why?, because I have a set of those goofy-strong solid neos that are a "pretty much" dead-bang fit for the 26D can.  When I say "pretty much", I mean that the height and arc are spot-on.  They are too long for the can though...so cutting them to length would be necessary.  GAK!  Still, a fire-breathing 26D drag motor would be pretty cool.

IMG_2379.JPG

 


  • slotbaker, Jencar17, olescratch and 2 others like this
John Havlicek




#2 havlicek

havlicek

    OCD Rewinder

  • Subscriber
  • PipPipPipPipPipPipPipPip
  • 10,288 posts
  • Joined: 20-August 07
  • Gender:Male
  • Location:NY

Posted 10 December 2017 - 07:55 AM

...all of which brings up the question...do people run 26D drag motors?  I don't recall seeing them used for this, even though some 26D motors even come with can mounting holes.


John Havlicek

#3 havlicek

havlicek

    OCD Rewinder

  • Subscriber
  • PipPipPipPipPipPipPipPip
  • 10,288 posts
  • Joined: 20-August 07
  • Gender:Male
  • Location:NY

Posted 10 December 2017 - 09:34 AM

Okey dokey then.  About an hour of cutting, cursing and removing magnetic dust got me a pair of goofy-strong solid neos that are pretty much a perfect fit for the 26D.  When I say "pretty much" now, I mean at least as good as Arcos, maybe better since these won't *need* a shim.  They could get a shim, but that seems like throwing gasoline on a fire because of how strong these are.  How strong are they?  I don't know as my meter won't measure them, but they sure don't seem to have lost anything at all from cutting them, and just getting them out of the can is difficult.  Placing them on my work table requires planning so that nothing magnetic is in the same zip code :)

au naturel:

IMG_2382.JPG
 

and dummied-up in a can:

 

IMG_2381.JPG


  • slotbaker, Jencar17, Tim Neja and 2 others like this
John Havlicek

#4 havlicek

havlicek

    OCD Rewinder

  • Subscriber
  • PipPipPipPipPipPipPipPip
  • 10,288 posts
  • Joined: 20-August 07
  • Gender:Male
  • Location:NY

Posted 10 December 2017 - 02:39 PM

I guess I'll do both.  :)  I ordered a 26D motor (*the can in the picture is fairly well past restorable condition, but works for general figuring) to take apart for this, and have done a bit more to the FT36D motor too.  If I'm going to go crazy, I may as well go twice as crazy.


  • Geary Carrier likes this
John Havlicek

#5 Geary Carrier

Geary Carrier

    all there...???

  • Full Member
  • PipPipPipPip
  • 266 posts
  • Joined: 23-April 16
  • Gender:Male
  • Location:CT

Posted 10 December 2017 - 02:50 PM

 

The other major contributor to the FT36D motor's weight is of course that big ol' thick-web-and-crown armature...BUT...a shorter pair of magnets means a shorter stack as well, so I made one up to fit.

Hi John,

 

Looks groovy, did you use the shaft from the Mabuchi 360 or the Mabuchi 36D on the big block?

 

Those big bearings are the same ones I'm gonna throw in the big block to go.

 

Still working on the winding stuff, I appreciate your encouragement...

 

 

Thanks,

g


  • havlicek likes this

Yes, to be sure, this is it...


#6 havlicek

havlicek

    OCD Rewinder

  • Subscriber
  • PipPipPipPipPipPipPipPip
  • 10,288 posts
  • Joined: 20-August 07
  • Gender:Male
  • Location:NY

Posted 10 December 2017 - 03:37 PM

Hi John,

 

Looks groovy, did you use the shaft from the Mabuchi 360 or the Mabuchi 36D on the big block?

 

Those big bearings are the same ones I'm gonna throw in the big block to go.

 

Still working on the winding stuff, I appreciate your encouragement...

 

 

Thanks,

g

 

Hi Geary,

     I'd like to use the shaft from the 360, because they're uniformly very good quality, but it's a little on the short side...although I think it will make it.  The other stack and shaft are from a "Tradeship Rewinder's Kit".  The lams are a loose-ish fit on the shaft, so you have to be careful NOT to mess with them too much before powder-coating.  The shaft on the Tradeship stacks is OK, but maybe not quite up to the 360 shaft, although long enough to go dual shaft, so I can just cut off the extra after the stack is coated.

     On the winding stuff, you're doing GREAT so keep it up.  Once the lights start to come on (*which took me a while!), things will start to happen much more quickly.  You'll start to figure ways to handle different lams, problems and even come up with your own "style" as a winder.  Before you know it, you'll be tackling "star winds", "hemis", "reverse winds" (TM me), doubles and triples...watevah, as the kidz say!


  • Geary Carrier likes this
John Havlicek

#7 havlicek

havlicek

    OCD Rewinder

  • Subscriber
  • PipPipPipPipPipPipPipPip
  • 10,288 posts
  • Joined: 20-August 07
  • Gender:Male
  • Location:NY

Posted 10 December 2017 - 04:57 PM

I got some more done on this FT36D drag motor.  I went for a little more eye-catching/modern look for the can and shot a coat of "Anodized Blue" VHT, and then overshot a coat of clear.  It's a neat effect that does look something like an anodized finish.  I gotta get some red and purple :)

IMG_2383.JPG

     I cut up an FT36D can to make a pair of shims that are clamped and epoxied to the backs of the magnets, and are curing.  Some quick and dirty figuring, after measuring the thickness of the can metal tells me that the end result (*within a few thousandths) should result in a nice tight hole for the 36D lams.  We shall see.  ;)


  • slotbaker and Geary Carrier like this
John Havlicek

#8 havlicek

havlicek

    OCD Rewinder

  • Subscriber
  • PipPipPipPipPipPipPipPip
  • 10,288 posts
  • Joined: 20-August 07
  • Gender:Male
  • Location:NY

Posted 10 December 2017 - 08:26 PM

Magnets are bonded to their shims.  Now I have to build-up a 26D and 36D end bell for the two motors and then put them aside while i wait for the 26D can.

IMG_2385.JPG

Inserting the magnet/shim pairs into the can proves there'll be a really nice and snug fit.

IMG_2384.JPG


  • slotbaker, Samiam and Geary Carrier like this
John Havlicek

#9 havlicek

havlicek

    OCD Rewinder

  • Subscriber
  • PipPipPipPipPipPipPipPip
  • 10,288 posts
  • Joined: 20-August 07
  • Gender:Male
  • Location:NY

Posted 11 December 2017 - 04:42 PM

I got the magnet/shim assemblies epoxied-in to the FT36D can, and all is groovy.  These magnets have much less cog than either the stock Mabuchi magnet-like things or the Champion Arcos, I guess because of their longer tips.  Re-checking, they measure just as strong after all the manhandling, and the gap is nice and tight.  In between doing all that stuff, I got busy on both the FT36D and the 26D end bells.  The 26D is getting the somewhat better Champion, so I did the "standard treatment".  The hoods got soldered and a pair of post sleeves.  After soldering, I slipped a washer underneath them to slightly raise them off the plastic.

The FT36D end bell needed more surgery because of the "Mabuchi Crack" which is standard equipment at this point.  In this case, the end bell bushing pocket was cracked on both sides, so in addition to drilling the end bell with four teensy holes so the lo-vis epoxy could seep out, I also made a brass collar that was a press-fit.  The whole mess was cured in one shot, left proud and then machined flush after curing.  I'm sure the end bell bushing is better/more securely seated than it was when new, and if the end bell is to be bracketed, the center holes will only need a little opening-up...something any builder should be able to handle easily.

IMG_2386.JPG


  • slotbaker, Tim Neja and Geary Carrier like this
John Havlicek

#10 havlicek

havlicek

    OCD Rewinder

  • Subscriber
  • PipPipPipPipPipPipPipPip
  • 10,288 posts
  • Joined: 20-August 07
  • Gender:Male
  • Location:NY

Posted 11 December 2017 - 07:42 PM

36D end bell is done.

 

IMG_2387.JPG

 

mocked-up:


IMG_2388.JPG


  • slotbaker, boxerdog, Eddie Fleming and 2 others like this
John Havlicek

#11 olescratch

olescratch

    olescratch

  • Subscriber
  • PipPipPipPipPip
  • 758 posts
  • Joined: 19-July 13
  • Gender:Male
  • Location:Ravenna, OH

Posted 11 December 2017 - 08:22 PM

That ring-around-the-pocket fix seems to be necessary for every one of these endbells, is it the cause of them failing?


John Stewart

#12 havlicek

havlicek

    OCD Rewinder

  • Subscriber
  • PipPipPipPipPipPipPipPip
  • 10,288 posts
  • Joined: 20-August 07
  • Gender:Male
  • Location:NY

Posted 11 December 2017 - 09:40 PM

They just get brittle with age John, and the way they were molded, that ring is the first thing to go.  ***BTW, the Mabuchi end bell plastic seems to benefit, at least a little, from boiling in water.  The Champion 16 and 26 end bells don;t do it at all from what I've seen.  A  lot of times, the crack doesn't really show up unless you really look hard, but oil and grime gets in there after a while and highlights it.  It used to be thought that these cracks weren't a functional problem, but I've had them fail several times and it can show up in pretty ugly ways while the motor is running.  There are some other more-hidden "gotchas" with the Mabuchis also that I get reminded of (like really recently!) and I don't have a surefire fix for...other than just avoiding the problem altogether.  Then there's the increasing problems associated with using old commutators.  At this point, and after five or so decades, the stuff is getting pretty dicey.


John Havlicek

#13 olescratch

olescratch

    olescratch

  • Subscriber
  • PipPipPipPipPip
  • 758 posts
  • Joined: 19-July 13
  • Gender:Male
  • Location:Ravenna, OH

Posted 11 December 2017 - 10:05 PM

Yeah!  I've just been seeing those cracks in all of the Mabuchi's I've been able to take a good look at.


John Stewart





Electric Dreams Online Shop