3573 replies to this topic

[havlicek]

Thanks guys. I actually boinked myself on the hardware. I wanted to move the screws a little further apart to better support the hardware on that big endbell ...so the regular springs aren't long enough. Because of that it was either use stock 36D Mabuchi springs (NOT!)...or wind some up out of guitar strings. Now that I've done one, I'll have to make sure I keep that in mind for next time. The motor runs really well though. Better news is that I just got off the phone with Barney and his 26D is running aces (whew!).

-john

[Jeff Buyer]

Re: Kemtron 5-pole rewind

John, I was finally able to build a car for the Kemtron rewind you did for me. As you might recall, one of the arms was bent, so I used the other setup that you had assembled and built a hardbody chassis for it. The motor runs awesome, pretty close to some of the six volt Kemtrons I have, only much smoother. Thanks for your craftsmanship on this motor.

Best regards
Jeff Buyer

[havlicek]

Hi Jeff...wow, I didn't remember doing any 5-pole arms that actually worked!? Jeez that's a surprise...no...really! Anyway, I was able to get that open frame motor apart you sent and clean everything up to reuse. It was tough to get the epoxy off the arm and still save the com. It's a small com with a hole for a 36D sized shaft, so it would have been difficult to replace the thing. So far...so good and now I just have to come up with a 1 ohm wind to match what was on there. I'll keep you posted.

-john

[Jeff Buyer]

Hi Jeff...wow, I didn't remember doing any 5-pole arms that actually worked!? Jeez that's a surprise...no...really! Anyway, I was able to get that open frame motor apart you sent and clean everything up to reuse. It was tough to get the epoxy off the arm and still save the com. It's a small com with a hole for a 36D sized shaft, so it would have been difficult to replace the thing. So far...so good and now I just have to come up with a 1 ohm wind to match what was on there. I'll keep you posted.

-john

The one you did with the slight bend in the shaft works well, too, although I had to use an endbell with the timing adjusted to get some speed out of it. That arm might work if I put the gear on the other side. So basically both 5-pole rewinds were a success.

JB

[havlicek]

Hi Jeff...thanks again for the info! Your next one is done and I was able to strip it and rewind it without too much trouble (except for the epoxy that was on there). The thinnest wire I keep here is #30, so I tried stripping a Mabuchi and reusing the wire but got inconsistent results on the meter. I then did a #30 wind (lots of turns on that short stack) and it came in between .8 ohm and .9 ohm. The magnet on the motor is dead as nails and I couldn't get a reading much past 100...so it will need to be either zapped or replaced. I cleaned the motor up a bit but didn't cut the com as I wasn't sure how much was left on there:



-john

[Victor Poulin]

I must be getting real good John, as I can now spot your arms a mile away lol

BTW- Bill Fernald is coming over next week to work with me and start teaching me rewinding. I'm super stoked to get started !!
I'll try and keep you posted on how things progress as we move along.

I also have another question for you John. What do you use to test the arms? Just a reg ohm meter ? and if so, where can I get a good price on one ?

Thanks John for all the help, and all the great info you take the time to share with all of us.


Vic

[Prof. Fate]

Hi

The brushes on that motor won't survive a full race, sadly on that wind. I never did come up with a good solution.

Hotter than a 34 needed different springs, in this case, threading in a second spring inside the first to double the tension was required. But then the brushes would wear down very quickly. But I never found a satisfactory solution.

Fate

[don.siegel]

Was the stock 8V Atlas a 34 Rocky? The stock ones, even the 6V ball-bearing version, will run all day long... and they're already pretty fast! Can't wait to see how a 30 will do - altho sounds like I better look pretty quickly!

Don

PS: John, I may have some 33 or various other sizes lying around if you want some - just let me know!

[Jeff Buyer]

Hi Jeff...thanks again for the info! Your next one is done and I was able to strip it and rewind it without too much trouble (except for the epoxy that was on there). The thinnest wire I keep here is #30, so I tried stripping a Mabuchi and reusing the wire but got inconsistent results on the meter. I then did a #30 wind (lots of turns on that short stack) and it came in between .8 ohm and .9 ohm. The magnet on the motor is dead as nails and I couldn't get a reading much past 100...so it will need to be either zapped or replaced. I cleaned the motor up a bit but didn't cut the com as I wasn't sure how much was left on there:



-john

Nice work, John. I'm curious if you used the original springs, or the extras that I sent? One of the originals had cooked, so it's weaker and might not apply the right tension.

JB

[havlicek]

BTW- Bill Fernald is coming over next week to work with me and start teaching me rewinding. I'm super stoked to get started !!
I'll try and keep you posted on how things progress as we move along.

Please do Vic. Be forewarned that, even with some missteps (maybe I can help you avoid some of the ones I've made)...this stuff is like crack, not that I would know

I also have another question for you John. What do you use to test the arms? Just a reg ohm meter ? and if so, where can I get a good price on one ?

All I have is a decent multimeter Vic, but it can only resolve to tenths of an ohm, and not that accurately. Accurate milliohm meters are expensive and impossible for me to justify on a hobby budget.

The brushes on that motor won't survive a full race, sadly on that wind. I never did come up with a good solution.

Hotter than a 34 needed different springs, in this case, threading in a second spring inside the first to double the tension was required. But then the brushes would wear down very quickly. But I never found a satisfactory solution.

Fate

Yes, I pretty much figured that might be the case Rocky. The motor was cooked in any case (maybe partly because of the magnet), so Jeff can figure how he wants to proceed.

PS: John, I may have some 33 or various other sizes lying around if you want some - just let me know!

Thanks (as always!) Don. I rarely even use #30 wire except on double winds. If I had a bunch of these things to do, I'd just get a roll of #33 or #32. A one pound roll of that gauge is probably thousands and thousands of feet long. It's such a rare thing (so far anyway) that I need to use such small wire it seems a waste to have it sitting around.

Nice work, John. I'm curious if you used the original springs, or the extras that I sent?

Thanks Jeff I used the existing ones and just gave them a bit of a stretch and was planning on sending back the extras. When you get the magnet sorted on the motor, I think you'll be pretty happy with how it runs. There must be a neo or even a modern ceramic out there that either fits or can be cut down to fit, depending on the orientation. They are cool little motors, amazingly simple and about perfect for a trim little F1 car like a nice old Honda or sumpin'

-john

[Bill from NH]

Jeff, if that's an Alnico magnet, try to zap it before you replace it. That might be all it needs, Alnicos are known to weaken when an open frame motor is disassembled.

[Prof. Fate]

Hi

Ya, that lump of iron really benefits from being regularly zapped.

As for the motor, My late Friend Jose Rodriquez jr who was the impulse behind the Atlas stuff (he once sent me sketches of proposed motors they decided to NOT build) that the 6 volt arms were huge failures. The odds were 50% that the wind would blow within the first couple minutes of getting power the first time!

I have some 208s and 206s that have 40 years on them, but it took a lot of work. But that is outside the scope of John's winding thread.

You might not know that there was a version of the 206 with overhead brushes and normal springs like a pittman 196. THAT layout is so much better for this motor from a reliability standpoint and will work better with the rewinding as well.

Fate

[Jeff Buyer]

Jeff, if that's an Alnico magnet, try to zap it before you replace it. That might be all it needs, Alnicos are known to weaken when an open frame motor is disassembled.

I plan to do just that, but I do have a NEO ready to go in this motor that I want to try as well.

[havlicek]

I finished up an FT36D for Marc Franco. It's a Champion setup with Arco magnets. I did up the endbell with D motor hardware and a set of Camen Springs. I even fabricated a set of "elephant ears" out of some sheet aluminum and, while the material is thinner and a little more bendy than the Mura ones, they work well and should be fine installed in the car. I also cut out the Champion can shim so both the top and bottom of the motor can breathe a little better:



The arm was a Tradeship blank that I added a big ol' honkin' Kirkwood com to after reaming it out to fit the larger shaft. The wind is a #29 double and while the setup can probably take a #28 double, I figure a #29 double will run cooler and last better. The motor does run fairly cool and revs very nicely. The elephant ears aren't "necessary" but I always wanted to do a set for a Mabuchi and they sure can't hurt. Besides, I think they look cool

-john

[Pablo]

John,
I track tested the Speedy Gonzales Buzco car today.
The Havlicek motor performed perfect.
It runs cool and smooth. Exactly what I wanted.
Mission accomplished, Thanks John

[havlicek]

Hey thanks for the update Pablo. I bet it handles really well with that nifty Pablo chassis too! I get the biggest kick when one of my motors gets installed in such a nice car...makes the motor look way better I bet the owner is going to be a happy camper with such a lovely car showing up on his doorstep!

-john

[HarV Wallbanger III]

John I will get you one of my old meters for arms that I sold years ago. (that many copied) I think I can talk him into doing another as he still has boards left from the project years ago. Thank you for the motors! It may take awhile to get him to do it but I'll talk to him this week.
barn

[havlicek]

Hi Barn,

Just the offer is a stunner. Of course you're always welcome for the motors and I'm stoked to have them in any Team Cort cars too!

-john

[Horsepower]

Hi John! I rememeber when you first came to this forum and were asking a lot of questions, and we provided parts and answers the best we could. Now the tables are turned and I'm just amazed how these motors turn out. It looks like you were "born to wind"!

[havlicek]

Hi Gary,

I remember too...and I also remember that you were among the first to be really supportive and helpful. There were also others who probably thought I was strange because after all, why would anyone want to wind an armature when people just bought them and threw them away (even whole motors!). In fact some pretty much said that

Now the tables are turned and I'm just amazed how these motors turn out.

Not at all Gary...I still learn every time I do an arm or build a motor! I may never "get there"...but I am enjoying the heck out of the journey.

It looks like you were "born to wind"!

I don't know Gary, I think that a LOT of people would be doing what I do if they gave it a try and stuck it out a bit. In fact I'm sure of it because, after all, every other kid in the 60's had a LaGanke and spools of magnet wire!

-john

[Pablo]

"Great spirits have always found violent opposition from mediocre minds. The latter cannot understand it when a man does not thoughtlessly submit to hereditary prejudices but honestly and courageously uses his intelligence and fulfills the duty to express the results of his thoughts in clear form." Einstein.

Havlicek rocks.

[havlicek]

Pablo rocks. As I recall, there was only one other guy (I apologize if my memory is faulty) winding arms when I got here...Pablo!

-john

[havlicek]

I'm getting another FT36D motor together now that I have a better idea of what they can handle. The first thing I wanted to do is to install bearings on both ends because the stock bushings always seem a bit sloppy. The problem I've run into is that the shafts on these motors are somewhere around .087" (I think) and they fit just as sloppy or more in 3/32" ID bearings. I've tried bearings "made for this shaft" both old and new and they all seem sloppy. It seemed that the way to go was to use a 3/32" axle as a motor shaft and a pair of axle bearings. The axle I used measures somewhere around .091"-ish (again from memory) and it's a lovely slip-fit in the bearings with no detectable slop. Those few extra ten-thousandths made pressing the shaft into a 36D stack pretty danged tough though, and I had to do it in stages to get the stack on there. Anyway, once the shaft and stack were assembled, I had to ream out a Mura com and again, a few extra ten-thousandths made this difficult. I have a spiral carbide abrasive bit that normally opens the com hole up JUST enough, but I had to go a little further. I wound up twirling a twist drill bit in my fingers to slightly widen the com hole. Then it was time to work on the can and end bell.

Removing the caged bushing in the can and installing a bearing is pretty straightforward in a Mabuchi...but it's the endbell that really needs "surgery" to get a bearing installed. The bushing pocket is just too small for a snap-in replacement. So the end strap needs to get cut in the middle and a bearing-carrier strap installed. I used tool steel this time because...well...just because it was within arms reach. I've used brass before and it works well too, although I guess steel is better. This would almost definitely be MUCH better and more accurate with a drill press, but I was able to get it done with a bunch of fiddling and squinting. The bearings are well aligned now as the armature will slide easily in the setup. So after all that, I can now start making up an arm and get to winding. Best part, the arm spins for days in the setup and smoooooth!



-john

[Pablo]

Axle shaft and 3/32 BB's oh my

It gives me goosebumps.

One of these days I'm going to ask you to wind me up one just like that,
really really hot and dangerous.

[havlicek]

Thanks Pablo...I'm thinking this one will be hotter than the previous few. I'll probably go for a #27 single wind just for the heck of it. A #26 single would probably make a cool drag motor though!

-john