[Pete McKay]

OK, I don't know if this is the ultimate psyche job or that one of our drivers is actually onto something revolutionary.

We have a driver who is an electrical engineer, he rewinds armatures for a living basically. Last night I watched him change out a M/T armature with one he "modified", and listening to it warm up it almost sounded like a horizontal arm car, with that much RPM. He only ran half a dozen laps with it then pulled it off, but here's his story.

Remember that this is a vertical axis Magna-Traction armature. First, what he does is de-wind the armature until it reaches a certain resistance in ohms. No, he wouldn't tell us what that figure was, but he says the resistance from pole to pole was nearly identical. Then he epoxies the wires with some sort of home made formula that is hi temp and hi stress. After that he uses a very sophisticated balancer to file the outside of the stack so that it's nearly perfectly balanced when it spins. This isn't the simple two razor blades balancer; this is something that actually spins it and measures out of balance locations digitally, just like tire balancing. Again, he won't tell us where he got the tool, but we have seen it.

The car does not have zapped magnets, only this blueprinted armature, and it's very quick out of the corners but tops out quickly on the straights. I'm sure that he's lowered the moment of inertia for spinning the arm up, but I'm really interested what it'll do with zapped magnets. I'm no engineer, but I would appreciate anyone out here who is helping me out here.

Is this a psyche job or are we about to be handed a real beat down?

 

[22tall]

I'm pretty sure that zapping only gets them back to original full strength. I've heard of reverse zapping and never understood it but they are banned in some race organizations. Zapping and matching would be the best combination. I would guess your friend isn't using standard mags if wants to get the most out a low ohm arm.

Maybe mtyoder will see this and add something. He did a really sweat tjet for me.

 

[sethndaddy]

years ago I had about 20-30 magna tractions, and obviously 2-5 where screamers, and it depended where I was racing which car I would use.
the only thing I ever did was clean, oil, and put silicone tires on the rears and I would blow the doors off the "home field racer" who every week had a new car that was going to kill me because of his super tuning skills........lmao........and he smoked weed every week while we raced too. I creamed his 130.00 car with a box stock car.
This lil sport of ours does take some skill.

 

[roadrner]

and he smoked weed every week while we raced too. I creamed his 130.00 car with a box stock car.
This lil sport of ours does take some skill.

Must have been interesting watching him race with a controller in one hand and a bag of Doritos in the other. :freak: rr

 

[mtyoder]

Dosen't seen that crazy to me :freak: ! I'd like to have a balencer like that! You know they make neodymium magnets for tjets. I have some. I run arms that read about 4 tenths of an ohm. These cars are just for drag racing. I've had mine run my 17'-6" strip in less than 4 tenths of a second at about 50 actual mph(yes, there are cars much faster than mine). I've seen windings and commutator plates fly (the metal part of the com not the whole thing). I've done plenty of re-winds from mild to insane. It's kinda tedious and kinda fun at the same time. If you wanna try this my advice is to buy good winding wire from an electric motor shop. They got the good stuff with the high temp coating. As far as guage, stock magnets 38-44ga., blue/yellow 36-38ga., polymer 34-38ga., neo 30-34ga. These are just suggestions for guage 30ga. is big wire 44ga. is small wire. With all the jl arms out there you'll have plenty to practice with. I like th jl's cause it's easy to add laminates. 3(stock) 4,5,6 or stuff like this.

 

[T-jetjim]

Mtyoder- That armature is crazy! I have never rewound an armature so I don't know how hard it is to stack the lams like you did. Looks cool though!
Jim

 

[41-willys]

I would like to see the chassis that monster goes in.

 

[mtyoder]

I would like to see the chassis that monster goes in.

Here's the chassis, whole car, and the aftermath!

 

[41-willys]

That had to hurt! Did it run good once?

 

[Pete McKay]

Insane!!! Wait...neo's for MT's? Are they commercially available?

 

[mtyoder]

Insane!!! Wait...neo's for MT's? Are they commercially available?

The neo's are for tjet. I don't think anyone makes them for magnatraction. They might still be available through sluggercan.com.

The car ran quite a few passes before the crash that ended it's life. It ran pretty well, but didn't wanna stop after it got wound up.

 

[Mike(^RacerX^)]

Mtyoder,great stuff.I have my dad scouring his shop for old motors from cars(alternators,power window,wiper,etc) to salvage wire from.

Ive been messing around with it,and you're right,it is tedious,but a lot of fun and rewarding when you get one to run.

Hey Pete,check Alan Galinkos site,I know he has poly MT magnets:

http://www.slotcars.org/hodra/ag&g.htm

Mike

 

[noddaz]

well, ok

Everything sounded ok until I reached this...

Then he epoxies the wires with some sort of home made formula that is hi temp and hi stress.

I think all that would do is add extra weight and cause the arm to retain heat...
(I have never re-wound an arm...)
But this I find extremely interesting...

After that he uses a very sophisticated balancer to file the outside of the stack so that it's nearly perfectly balanced when it spins. This isn't the simple two razor blades balancer; this is something that actually spins it and measures out of balance locations digitally, just like tire balancing.

Can you get us a picture of this device?

Scott

 

[mtyoder]

I don't epoxy arms that I run with stock magnets. I've done some polymer magnet arms without epoxying too. Neo arms are a different story, those arms really spin. I use the two part stuff that comes in the siringe. They make it in many different grades. High temp too. Some people add epoxy to the lighter side of the arm to balence it(epoxy balancing).

 

[Ragnar]

OK, I don't know if this is the ultimate psyche job or that one of our drivers is actually onto something revolutionary.

We have a driver who is an electrical engineer, he rewinds armatures for a living basically. Last night I watched him change out a M/T armature with one he "modified", and listening to it warm up it almost sounded like a horizontal arm car, with that much RPM. He only ran half a dozen laps with it then pulled it off, but here's his story.

Remember that this is a vertical axis Magna-Traction armature. First, what he does is de-wind the armature until it reaches a certain resistance in ohms. No, he wouldn't tell us what that figure was, but he says the resistance from pole to pole was nearly identical. Then he epoxies the wires with some sort of home made formula that is hi temp and hi stress. After that he uses a very sophisticated balancer to file the outside of the stack so that it's nearly perfectly balanced when it spins. This isn't the simple two razor blades balancer; this is something that actually spins it and measures out of balance locations digitally, just like tire balancing. Again, he won't tell us where he got the tool, but we have seen it.

I believe to a certain extent he may be pulling your leg there. Not that I don't believe he modified the arm, I just believe he did it slightly differently than what he's telling you. To get the kind of response he seems to be getting, what I would do is completely de-wind the arm and then re-wind it with the same number of winds of slightly smaller guage wire. This would have the effect of giving me slightly more RPMs plus more torque. Yes, he should epoxy any re-wound arm. You can buy high temp, high stress epoxies that are sold for the purpose of using on armatures. These are available through some of the top 1/24 scale shops and distributors. You can also get these epoxies at electronics stores that sell motor winding equipment. There were at one point several dynamic balancers available to slot car racers for balancing armatures, we also used them for balancing wheels in 1/24 pro racing. You can still find dynamic balancers produced by a few high tech companies and even sold by a couple of specialty slot car companies dealing with 1/24.

The car does not have zapped magnets, only this blueprinted armature, and it's very quick out of the corners but tops out quickly on the straights. I'm sure that he's lowered the moment of inertia for spinning the arm up, but I'm really interested what it'll do with zapped magnets. I'm no engineer, but I would appreciate anyone out here who is helping me out here.

On these types of motors, zapping the magnets can add to their performance. But yes, you should zap several magnets and match them. The most important part of that would the matching of magnets.

 

[FastMann]

What? Slow down, I didn't catch any of this. I don't understand all this armature winding talk. The last thing I rewound was a tape of Sunday's ball game. My head hurts. :freak:

 

[Pete McKay]

The neo's are for tjet. I don't think anyone makes them for magnatraction. They might still be available through sluggercan.com.

OK, Scale Auto has a set of polymer magnets for the M/T, I ordered a set today, at $15 a set I certainly hope they're good. Unfortunately they're not legal in any series we currently have, but who knows, maybe for the summer series something will be written for them.

The balancing device is at the racers house, and it never leaves his house. It resembles a lathe in that you chuck the shaft into a motor and it spins the arm up to 1000 rpm. From there it registers on a laptop screen where it's out of balance. Now it could be for a different application, this guy worked for a company that made hi speed brushless motors and got it from there, but it's pretty cool seeing exactly where to file the stack to weight balance the arm. I'll stick to my two razor blades myself, at least I understand that technology.

 

[Mike(^RacerX^)]

Well doing a little research today,I figured out that Fender Telecaster guitar pickups are wound with 42ga wire.I happen to have a few so with the amount of wire on just one pick up,I could wire about 4 billion armatures.

So today I ran with the idea of adding lams to a tjet arm.I did one with 5 as an experiment.

WHen I check the ohms of just one pole,in other words,from the start point to the finish,will that number be divided in half once I am done and go pole to pole???
I know,its a basic question,but for some reason I had a bit of a brain fart and couldnt remember.

So the winding went ok.Got all three done,and then cheesed it because I was in a hurry and busted a few windings.

How the hell do you guys keep track of the start and end points of the wind on each pole?????
I tried a small piece of masking tape.Didnt work well.

Interesting and educational getting as far as I was able to get.Live and learn,and never have failure as an option I say.

Mike

 

[sethndaddy]

I won't change the oil on my real 1:1 truck, i'll be damned if I'm going to tinker in so much detail with my 970 little toy cars, lol.

 

[mtyoder]

Well doing a little research today,I figured out that Fender Telecaster guitar pickups are wound with 42ga wire.I happen to have a few so with the amount of wire on just one pick up,I could wire about 4 billion armatures.Mike

The winding wire on those pickups probably has a low temp. coating. Pickups don't generate heat like a slotcar arm so the coating dosen't have to be high temp. I used to use the wire from bad tyco wall warts. I found out the hard way that it has low temp coating as well. Kept toasting them. The motor shops use wire with 600 degree coating and sometimes it's double coated which is hard to solder!