45 replies to this topic

[olescratch]

Whew!  John, you're really giving it your all to complete this monster!  I would've given up when the first cloud of dust ignited lol!  I'm nonetheless, waiting to see where you go next. 

[havlicek]

Whew!  John, you're really giving it your all to complete this monster!  I would've given up when the first cloud of dust ignited lol!  I'm nonetheless, waiting to see where you go next. 

 

 

I knew going-in that the magnets were going to be a huge PITA John.  Still, this was my first set of arc-segment neos, and that alone caused a LOT of cursing.  After all this, it gets a little more straightforward.  I mean, the end bell is cracked around the bushing, and I have a pretty good fix for that.  The hoods need to be soldered to the "heatsinks", and I think should be spaced off the end bell plastic with phenolic washers...check.  Of course, the motor will need shunts because it's gonna be a bigwire arm...duh!  I have to pick a commutator, but I have several choices for the larger shaft and have to balance a couple of different things to figure the best choice.  Winding will be the least of it.

[Foamy]

Heating the magnets to set the epoxy will kill most of the magnetism.

Alpha can rezap neo magnets. The fixture on my machine is too small for 36D motors or I would offer to do it.

 

[Foamy]

As far as catching me, that motor was a tame one because it was supposed to be no glue. It turned into a glue race.

Vintage Champion Arco magnets, good 2mm bearings, Parma D-can endbell hardware, a rewound arm natch...

[havlicek]

 

Heating the magnets to set the epoxy will kill most of the magnetism.

Alpha can rezap neo magnets. The fixture on my machine is too small for 36D motors or I would offer to do it.

 

 

Hi Dennis,

Of course I keep the temp low enough to not affect the magnets.  These are as strong now as they were before, but it's good to know Alpha can zap them.  Thanks for the info.

 

As far as catching me, that motor was a tame one because it was supposed to be no glue. It turned into a glue race.

Vintage Champion Arco magnets, good 2mm bearings, Parma D-can endbell hardware, a rewound arm natch...

 

 

Natch   It's not just about power...but getting that power to the track!

[havlicek]

Got this arm done (*except for balance), and of course it makes absolutely no sense (*except for the drag crowd).  16 turns of #23 reverse-wound (three layer coils) on the stock length stack, minus the fiber end insulators is pretty ridiculous.  Then again, these magnets are pretty ridiculous as well.

[havlicek]

In between working on this arm and some other stuff, I got busy with the end bell here.  Of course, the "Mabuchi Crack" around the bushing was there and needed to be addressed.  Even though this motor is can-drive, anything not right should be attended to, so the end bell got drilled with four 1/32" holes and lo-vis/high-temp epoxy was applied to the outside of the bushing and the inside of the bushing pocket so that I saw squeeze-out on the outside.  I think that this method of "keying" the bushing to the end bell (*the epoxy will of course bond to the bushing, but not the end bell...the little holes allow the epoxy to form solid "pins" between the bushing and the endbell) is about the simplest way I can figure to do something about all this and still leave the end bell in tact.

The hoods got soldered to the brush tubes with a lotta solder because the flat type hoods leave very little contact area with the brush tubes.  The hood/brush tube assemblies then got reinstalled with a fiber washer underneath.  I'll still have to work shunts and leads, but that can be done when the motor is being assembled.

[Geary Carrier]

 

As far as catching me, that motor was a tame one because it was supposed to be no glue. It turned into a glue race.

Vintage Champion Arco magnets, good 2mm bearings, Parma D-can endbell hardware, a rewound arm natch...

Hi Dennis,

 

Do you happen to have a picture of the dragster this motor was in?

 

Thanks,

g

[Foamy]

Here on Slotblog, go to...
1/24 model racing>proxy racing>2017 rods and rails inspection line
On page one of three.

[Geary Carrier]

Thanks Dennis...

[havlicek]

Post mortem.  I got the arm back from balancing and set about to assembling this thing, which was a PITA.  First off, the magnets are so strong, I had to clear a wide swath on my work bench...and the darned thing still grabbed a large set of pliers.  Then too, putting the arm in and out of the can to get the centering done was awfully difficult, but I got past that and all was well.  I installed a nice new set of brushes and wound a set of .015" 3-coil springs a little past 90 degrees and nervously powered it up.  Why so nervous?...well, because I wasn't at all sure I had assembled the segments correctlty even though the compass showed two N and two S on opposite sides.  ***The motor fired right up and spins really smooth, so the balance job is right-on according to my "feel-o-meter" (*ie: fingers).  Surprisingly, even though it's REALLY difficult to spin the arm with my fingers, the motor draws *only* around 3 amps.  Now, that might sound crazy for a Mabuchi FT36D, but really for these magnets and this armature, that's positively reasonable.  I don't really have much experience with really hot arms/solid neos and FT36D motors, but this motor sure seems like a strong drag motor!

 

[olescratch]

Picture please!

[havlicek]

Picture please!

Hi John.  Motor is packed-up and ready to be sent to Australia today.

[olescratch]

Darn!  Like to see them 'gems'!  

[Tom Katsanis]

I will try & post a photo when I receive it.
Tom

[Tom Katsanis]

Motor arrived today so some pics as promised photo aren't the best sorry.
Tom

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[olescratch]

Thanks for the pics!

[Tom Katsanis]

Here is a few pics of the car being built by Pete D of Mr Slotcar.
I will post some pics of the car when done & also what it ends up running when it finally gets down the track.
Tom

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[Tom Katsanis]

Managed to get a .807 run today out of this baby today a true testimony to the qaulity of John's builds.

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[Kim Lander]

Oh lord this is going to be a fun one to follow.

[Jim Lange]

John, wouldn't it be easier to kill the magnets with a torch, the cut, glue, shape ect. Then simply send the set up to Sonic or Alpha to get zapped? Just a thought.