winding a motor

[JohnRobHolmes]

upon request, i have decided to make a thread devoted to winding a motor. it is a simple task. higher wind motors spin slower and can be more efficient. smaller guage wire is used, and the motor draws less amperage through combined inductance and resistance (as compared to a lower wind motor)

you shall need
1- an armature and can from an old motor (or new, whatever)
2- new ceramic coated motor wire (can be bought in a three pack at radio shack)
3- a knife to scrape off the wire coating in places
4- soldering iron and solder
5- wire cutters
6- patience

to keep everything simple, i will only use a single wind pattern. in theory a 30 turn single should be the same as a 30 turn double or a 30 turn triple. some people say they can tell a difference in the power band. lets just keep with the single wind pattern.



first, take your old motor apart and inspect it, clean it, and get it ready to be stripped of wire. the can is the outside of the motor, and the armature is the inside that is wrapped with wire and spins on a brushed motor. if you are lucky the armature does not have epoxy on it. take the wire off, starting where it is attached at on the comm. unwind carefully, noting how it is done. this is how i learned.

the motors that we use are 3 pole motors. look at the comm where the brushes hit, notice 3 seperate parts? you should. each comm pole is situated 60 degrees off from a stator. there are 3 stator sections because there are 3 poles to the motor. the wire wraps around the stator.

to wind the motor
start with some excess wire leading past the comm where you want to start winding. attach the wire to the comm loosely for now, there should be tabs that it was sitting in previously. start winding in one direction or another- it doesnt matter. just keep track of your winds.

if you are doing a 30 wind single, wind around a single stator section 30 times. KEEP IT TIGHT AND EVEN!!! this is the most important part. try to follow a pattern and keep each wind next to the last. wind from the inside out, and back again until you finish your winds. each time you pass by the comm you made one wind. once you reach 30 winds, the wire goes to the next slot on the comm- keeping the same forward direction of winding. there is only one slot anyway, as you started on the other comm slot that is by the stator section you are working on.

VERY IMPORTANT!! the slot where the wire sits on the comm needs to be free of coating. drape the wire through and make a small mark on either side of the slot so that you can scrape off the coating with a knife. after you pass the wire through, continue the motion onto the next stator. wind 30 TIGHTLY, pass onto the next comm slot being sure to remove the ceramic coating at the right spot, and do it once more. now you should be where you started.

at this point you should have a fully wound motor with two loose wires wanting to connect to one comm slot. tighten the wires, remove the coating and move to the next step.

now you want to connect the wires to the comm. on some motors you can get away with just a press fit, but doing by hand is better with solder. start with the two free wires that need to be connected. keep them as tight as you can, and solder them up. repeat for the other two poles.

ALL DONE! if you have any questions or comments, add them up! maybe someone has some tricks that i dont know.

[JohnRobHolmes]

oh yes, i forgot about wire size. 280 motors can use very small wires. i think i used 28 guage for the 90 wind in the pic. its the smallest wire in a radioshack 3 pack. i know i could have gotten 100 winds, but i didnt want to risk winds falling off the arm. you basically want to fill up the armature as much as possible. if i only put 10 winds in with the super small wire, it would probably catch fire. the lack of inductance from more winds would make the wire draw more amps than it could take.

for less winds (and a faster spinning motor), use thicker wire. with 12 or 14 gauge wire i could only manage 3 or 4 winds on a 280 probably. the same principles work for 540 motors, only they have more rotational inertia, and epoxying the wires down is a good idea. if they are just a bit loose they will spin apart. but then you have to balance the bigger motors too. unless of course you wind a 65 turn like i did. it spins so slow that it doesnt matter. i used the medium radio shack motor wire if i remember correctly. but i digress...

[sambmx]

Thanks that post is very helpful, on a standard 540 motor about how many more winds are possible with a wire of that guage? Will it work it to go with a higher guage wire and more turns than you have there for more torque because id imagine theres a point where to high a guage will melt or before that produce less torque ?

[sambmx]

oh you posted as i was typing.

[SR5Dave]

Thank you sooooo much John!!! That is the kind of tech we are looking for here Time to read up and screw around!

[cotharyus]

Yes - I would always recommend epoxying the wires on a hand wound motor. You can also use epoxy to balance the motor after you have it done. The easiest way to balance an amature is to suspend the ends of the shaft on two level edges. The heavy side of the arm will rotate down. Mark the sides, and add or sand of epoxy as needed to make the arm sit completely still (not rotate) when you suspend it between the two flat edges, no matter which side of the arm is up. Back in the day, the only way to get a really good modified motor was wind it yourself. My first tamiya frog met its end at the hands of a 9 turn I wound...

[JohnRobHolmes]

there is a lot more to know, but i dont remember motor theory enough to spout out torque contants and rotational speeds and whatnots. it takes too much math, and too much guessing on the magnetic strength and so on.

to answer your question about winds again sam, you could use 32 guage wire on a 540. BUT, you would have to wind enough to create inductance (resistance to current changes) and a magnetic field. the motor would be sooooo slow with enough winds- probably only a couple thousand rpm at most. i bet you could get a 200 wind motor with patience. bump up the guage of wire to 26 (the green wire in the radio shack three pack) and you could get 75 winds on or so (im kinda guessing, all armatures are a bit different) and your speed would increase from the larger wire (less inductance= less magnetic field= more amps= more speed and heat)

to further clarify a few points (am i going to far again?)

more winds = more inductance THUS drawing less amperage (longer runtime for me )
more winds = a slightly stronger magnetic field (i.e. torque) PER AMP because of the more efficient field, slower spinning armature and less tendancy to stall because of the lower rpm/volt (Kv) rating

less winds = a weaker magnetic field at higher rpm THUS faster spinning armature
less winds = less inductance and resistance THUS letting more amperage flow through.

keep in mind that when your amp draw goes down your power goes down too. but you can offset that by increasing the voltage.

8O i love theory, but i hate the math

[Grizzly4x4]

Nice article John, thanks for doing that.
I am still sketchy about some things but at least I know that it can be done so I will try it out. I'm sure I will understand once I tear a motor apart.

"A little bit of knowledge is a dangerous thing"

[BigSmokinGun]

He scratches his head wondering, "If I make me a 90 turn motor, just how little gear reduction do I need? Could I get away with direct drive to the output gear in the tranny? Hmmmmmmm! That would make for a DTT!!"

[JohnRobHolmes]

i am wondering a similar thing. if i could get a hold of some nice inline or planetary reduction units and bolt the motor through it direct to an axle input, then i will get a clod style tlt for example. wonder if it would work.

or just use a huge high wind motor as THE tranny in the middle. we are almost getting into stepper motors now though. oh yeah, steppers.

[BigSmokinGun]

John, do you think a 90 turn would have enough power to do this? Or would atleast a bit of reduction still be needed? Eric

[JohnRobHolmes]

well, if it was a 540 or 550 can, it would have gobs of torque. you could still gear it down direct drive like that. all you are missing is the pinion/spur reduction. are talking about something with clod size tires or 2.2's? whats the reduction at the axle? i would bet that you could make it work just dandy- just figure out the rollout and final ratio. you could always throw an inline reducer on the motor as well.

[BigSmokinGun]

I had my TLT in mind at the moment. If I wind a 90 turn 540/550, put as small a gear as I could on it, and run direct to the output gear. It'd have 2.2's on it. Guess if that didnt work I'd try an inline planetary reduction like you said. If this setup works I'm thinking put the motor in the "engine compartment" and run a shaft to the "transfer case".

Dont know about a motor on each axle, might as well be a clod then.

Eric

[BigSmokinGun]

I have successfully hand wound a 70 turn. I used a Midnight 2 I had laying around. Just got another from a friend so I'll try a 100 turn!!

Heres how I did it on the Midnight...

Take the brushes out of their holders...unscrew the endbell screws...take off the endbell...pull out the armature if it didnt come out with the endbell(becareful of the small washers on either end of the arm.)...pry up the 3 little tabs on the comm. holding the wire(I used Xuron nippers to pop them loose, DO NOT nick up the comm where the brushes run!)...unwind all the wire...rewind according to Johns directions...reassemble it.

I used the green wire from Radio Shack's kit. I would reccomend soldering the wire where it goes through the 3 tabs before reassembling it. Mine didnt work at first so I had to pull it apart and do that, now it runs fine. I felt I had the wire tight so I didnt epoxy it either, time will tell I guess.

I just stuck it in my TLT last night and hooked a batt to it. Hard to say how fast it will be, dont have electronics in it yet. It does seem to hold the truck still pretty well though.

Has anyone else tried hand winding yet?

Eric

[killercrow]

hey cool, you guys really do get into the custom aspect of the hobby eh! good, i like it!
i have recently been winding my own motors, just rippin apart stock 540s and whatnot... i have 2 speedgems i might gut... but anyhow, i first put together a few 17 doubles, they got pretty good top end for bashing. and also some 40 turn singles which i havent tried yet.
well, my only disagreement here would be the soldering. at first i soldered, and the solder desoldered itself... that was in the 17 turns of course.... causing the motors to stop working... my guess is i just wound em too hot... anyhow, i made more without soldering, just used a flathead screwdriver and a hammer to crimp the wires on, and i havent had a problem yet. but i guess using the winds you guys are talkin about the motor probably wont get hot enough to desolder...
anyhow, yeah! cant wait to try the 40 turns... should be slow enough for me!

[montess]

We all have problems with stalling with our clodbusters, due to, what Ive read that the copper wire in the winds gets hot there for makeing it stall, so if I were to wind the motor that will be on the back axle a couple more times that should help the stalling by increasing the torque a little bit and running cooler? But would that cause any other problems? I am going to start winding two stock clod motors tomarrow.

[SR5Dave]

Originally Posted by montess

We all have problems with stalling with our clodbusters, due to, what Ive read that the copper wire in the winds gets hot there for makeing it stall, so if I were to wind the motor that will be on the back axle a couple more times that should help the stalling by increasing the torque a little bit and running cooler? But would that cause any other problems? I am going to start winding two stock clod motors tomarrow.

I don't know WHERE the heck you read that

The motor stall comes from a motor just not having enough power to go over an obstacle. Basically, the two motors get the same volts/amps, but if one is under a lot of load, it just won't spin. As a RESULT it will heat up some..

The way to solve it is lower gearing and a higher turn motor. Don't worry about doing the two different... I don't really think that'll change much for you.

[montess]

I read that somewhere in here I dont remember Ill try to find it, So I should be able to fix that prob. by doing a lot of turns on my motor and I do have 10t pinions.

[montess]

SR5Dave I read that in electronics under super rooster gets hot w/ stockmotors 8 down post by BultacoJim

[SR5Dave]

I can see why you read it wrong, its worded kinda funny... But it gets hot because of the motor stall, not it stalls because it gets hot.