Cutting a motor commutator & motor tweaks

[EddieO]

VTA guys still run brushed?

Maybe I do have a chance to sell the 600+ stocks and 1000+ 19t I still have!

Later EddieO

 

[killswitch]

Yeah I was amazed there are still people running 27t motors in VTA when I got back into touring cars. the 4 I sold yesterday were all to guys that decided to dust off their old touring cars and run some VTA without having to buy a new esc and motor. I run the novak 21.5 in a RDX, but I still like the way a brushed motor feels in a touring car. The one thing I dislike about the 21.5 is having to adjust the drag brake to make the car feel like a brushed powered touring car when off power. I tested one of your stock motors I had with some older pro-match 4 cell packs in my car the other day and I liked it, but it was a pain getting the car balanced out again after making the electronics swap. If the racing takes off locally, I may run 27t just to make the guys that are "brushless only" mad when I beat them with older technology. Plus, I still REALLY like building motors... Ive had pretty good results running 27t arms in scalers too Eddie. I liked my LCC with a 19t arm, 6 degrees of timing in a Ti can before I went brushless in it.

 

[EddieO]

Well, I got tons of stock and 19t motor arms for $5 each....

KD19 and c2 untouched with brushes and springs for $10....

Untouched random stock motors (I got p2k2, x stock, roar stock, some monsters, etc....)$10 with brushes and springs...also untouched

Later EddieO

 

[EeePee]

Integy V11 35 turn

 

[EeePee]

First shave on the Br00d 35 turn. Not run too much, I think 13 course runs and less than 30 minutes of practice would be close to correct. The serration lines are just barely visible on the brush.

Took off just under a 1000ths, not much at all.

 

[monkeyracer]

I'd love to see some NEO cans used for our purposes here. I'm kind of wondering (other than cost) why they never really got developed for crawling. I wouldn't mind testing one, but that will probably go to someone with a lot more experience to give (hopefully) better feedback.

I guess the theory is NEO will give a stronger magnetic field, and you can use larger stators which allows more copper, etc.
Stronger Mag = better drag brake, and more copper = more power... Am I wrong? And the whole set-up should be more efficient too right?

It seems a little sad that brushed is on the fading end with brushless being the way everyone went in other forms of racing, as it was said earlier in the thread it's been a "buy it, not build it" mindset with the crazy amounts of options for brushless available. I am from the build it mindset, and hardly have anything that is stock. That's what draws me to building motors.

One question though... On a motor where the windings have overheated and the insulation has burned, what is the best thing to use to clean the stator of any left-over burnt crap? I've re-wound it and tried to clean as much of the residue as possible, but I still get that distinct smell.

Also, on another motor I am re-building, if I threw a wind (not sure yet, haven't pulled it apart, but it's off-balance, and I am thinking that's what is up.) Was that just because of loose stock winds? (Meaning if I keep the winds nice and tight, is it going to happen again?)

And, lastly, what is the best thing to do to get rid of the tiny metal shavings that might accumulate on the mags picked up from driving around?

 

[EddieO]

I am working on a motor like you are describing......keep an eye out. Some of the theory is correct, some is a bit off....the big thing with our motors is that the two magnetic fields need to stay balanced.....you don't want one overcoming the other by much. NEO magnets are very powerful and currently that's the problem we need to figure out.

I feel you on the brushed/brushless issue. One of the most fun parts of RC for me has always been the putting stuff together. Motors were a highlight because unlike putting together other stuff, you could actually really get into the performance and make the motor better. Tons of little tips and tricks you could do. Lots of black voodoo magic....it's still there with brushless a little, but now it just seems the main thing is to keep buying rotors that have high gauss readings....at $30 a pop. I thought brushless was supposed to be cheaper?

If the insulation has burned, the arm is toast. The insulation is there for a reason and thats to prevent the copper from shorting.

Throwing a wind means the copper is blown apart. You more than likely had a wind shift. All that does is effect balance really. In a crawler motor, I would not worry too much about it on a machine wound motor. They are so out of balance usually anyways, I doubt you will suffer much loss on it. If it bugs you, you can use some thick CA glue to hold it into place.

As for the shavings.....I dunno why you are picking those up....but, Take the motor apart.....and clean it all with soap, warm water, and a tooth brush......it will get them all off pretty easy. Make sure you dry everything good.

Later EddieO

 

[JohnRobHolmes]

Tape works good to get shavings out of motors too. We have some ferrous rock around here and tape is about the only way to get it out.

 

[monkeyracer]

If the insulation has burned, the arm is toast. The insulation is there for a reason and thats to prevent the copper from shorting.

I didn't think the arm would have been damaged, but you know a whole lot more about this kind of thing, so I'll pull an arm out of another can.

Throwing a wind means the copper is blown apart. You more than likely had a wind shift. All that does is effect balance really. In a crawler motor, I would not worry too much about it on a machine wound motor. They are so out of balance usually anyways, I doubt you will suffer much loss on it. If it bugs you, you can use some thick CA glue to hold it into place.

The motor is really really out of balance, but I haven't pulled it apart yet to see what is up with it. It's a titan 550, so it may not be worth pulling apart, it would be more for curiousity than anything else.

As for the shavings.....I dunno why you are picking those up....but, Take the motor apart.....and clean it all with soap, warm water, and a tooth brush......it will get them all off pretty easy. Make sure you dry everything good.

Later EddieO

I drive on the street sometimes, which has tiny metal particles from steel belted radials, tiny shavings from snow plows, and other random little metal pieces. Even some of the trails have small little magnetic particles from ferrous rocks.

I will try the tape trick, I didn't think of that, Thanks JRH, and thanks Eddie for the help!

I'd love to see the Neo motors working. What about using 4 section or more for the neos to reduce the magnetic field overlap?

 

[EddieO]

Tape works too, just too redneck for me Can't get the bottom side very well though, a decent pressure of water blows them off no problem.....you can also just use an air hose from a compressor and blow them out....probably even easier than the tape.

With the NEOs, the overlap from 3, 4, or 8 magnets even won't really do it....its simply the massive power they make compared to the current arms....but I got a solution to that hopefully on the way....

Later EddieO

 

[monkeyracer]

Tape works too, just too redneck for me Can't get the bottom side very well though, a decent pressure of water blows them off no problem.....you can also just use an air hose from a compressor and blow them out....probably even easier than the tape.

I ended up just wiping them off, after rinsing as much off with water. The tape is a good idea though.

With the NEOs, the overlap from 3, 4, or 8 magnets even won't really do it....its simply the massive power they make compared to the current arms....but I got a solution to that hopefully on the way....

Later EddieO

Waiting patiently on this...

I know Neo's are strong, but I figure there's a certain thickness that will provide a strong enough field, but not too strong, and with that we can use larger stator diameters, meaning we can use larger gauge wire for the same number of turns.

Does your solution have anything to do with # of poles, or maybe donut shaped neo rings? Wonder what you are cooking up...

 

[EddieO]

They only get so thin, and pretty much all the thinner ones don't have the highest temp ratings, well at least the ones I can find.....

As for the segments (techincally a motor has two poles, a north and south)....I've not had time to mess around with the 5 segment stuff again yet. I have some of the arms......for all intents and purposes, I don't think they will ever make more power or a stronger field with the armature being the same size as we have now.. They will however be more efficient, have less brush wear, and will be a smoother powerband....

Later EddieO

 

[EeePee]

the 5 segment stuff...for all intents and purposes, I don't think they will ever make more power

Pointless then.

 

[EeePee]

Any of you guys use a Fussybrush?

http://www.fussybrush.com/index.php

I think someone said something to me about these...

I finally got a digi caliper so I can go the next step and get these brushes set up quick.

 

[EddieO]

Well, I dunno if 5 segment is pointless yet, as they should have a smoother powerband and more precise low speed control....will really probably just be a different flavor of motor....

I've used a fussybrush, I had one before they were ever released and the owner made me my own custom set.

They came in

Full Face Bit Sizes

Standard Comm - .270", .280", .285", .290" .300"
Large Comm - .320", .330", .335", .340", .350" 10

Serrator Bit Sizes

Standard Comm - .270", .280", .285", .290" .300"
Large Comm - .320", .330", .335", .340", .350"

I had all the little sizes in between, he basically cut me a bit like every .02!

They were worked great, they were just a bit time consuming to use.......

I still have some brand new kits some where, along with some of their little tools and their very cool comm replacement kits.

Later EddieO
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[whoodie]

Any of you guys use a Fussybrush?

http://www.fussybrush.com/index.php

I think someone said something to me about these...

I finally got a digi caliper so I can go the next step and get these brushes set up quick.

No, but I will now that I know that product exists, good find!

Looks like the largest size won't be quite big enough, but I'm sure it's better than filing the edges like I currently do.

 

[EeePee]

I think someone said something to me about these...

I still have some brand new kits some where, along with some of their little tools and their very cool comm replacement kits.

Eddie, it must have been you. :ror:

I want one.

 

[EeePee]

No, but I will now that I know that product exists, good find!

Looks like the largest size won't be quite big enough

Cool huh? :twisted:

I read somewhere, and I can't find it again, that even if you're off a few sizes it's still way faster for break in. The differences are small enough that the break in happens much faster.

 

[EddieO]

The fussybrush is no longer made.....I doubt the site even fully works anymore. Dwayne stopped making them years ago, he never even filled the last order I made.

I am planning on getting to the garage next week. I planned on doing it today, but a guy is buying my kit car, so I spent a portion of the day on that. Tommorrow the kids are off school and I am taking them to Toy Story 3....my first movie since coming home! Saturday, off to play magic (yeah, I am a dork).....so sunday at the earliest!

A fussy brush makes break in time virtually nothing......you are basically just seating the brushes.....less than a minute was the normal with them. It is critical your brush hoods are aligned though.....

Later EddieO

 

[EeePee]

Do what you want, but I want a fussybrush when you get the chance. "thumbsup"

You got different bits or sizes?