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Thread: Re Winding a motor. (28AWG wire)

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Old 06-24-2011, 08:18 AM   #21
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Thank you for both of your points of vues...

It's supposed to be just a tech question and I would not want to creat any problems between other members by asking some noob question that have been debated for a long time...

So, just the technical points of vues and for the rest... lets blow the wind...
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Old 06-24-2011, 08:20 AM   #22
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I do crawl bud. Going tomorrow too! Wee! With a working wife, 4 kids, and a company to run....it leaves little time for play time.

My racing examples are just as solid. We can go all the way up to stock motors in it, even hand wound stockers with bigger wire wore no faster. I guess 27t stock motors operating on 4.8 volts are at brush saturation too.

Please keep in mind, that of my local crawler guys....not all run big wire stuff. I rebuild all of their motors quite often and NONE of my crawling data shows any additional wear on big wire arms to small wire arms. I do a good 10+ rebuilds a week from stuff all over the world...yet to see any additional wear on big wire stuff.


Later EddieO
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Old 06-24-2011, 08:30 AM   #23
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Glad to help out Big Pitt. Don't mind us. Eddie doesn't ever agree with me for some reason.


A crawler motor with more power will wear faster, put simply. Disagree?
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Old 06-24-2011, 08:33 AM   #24
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I dunno about ever.....I am pretty sure I've agreed with you on stuff in the past...

But I disagree on your findings with this......

Who knows though, I guess a few members on here think I am talking out of my ass about motors....

Later EddieO
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Old 06-24-2011, 08:37 AM   #25
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So to keep the fire burning

Last reasonable T calculated:

At 27AWG:
=> 201 x 60T = 12060 Total CM ( only 370CM added...)

At 26AWG:
=> 254 X 48T = 12192 Total CM ( only 502CM added...)

Who's going to aswer first...
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Old 06-24-2011, 08:40 AM   #26
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I'd probably try the 48t if you are after some more power. The torque loss won't be anything to notice really and you can probably utilize your gearing to compensate.

It should fit, but if it doesn't.....make it a 46 or 47....maybe a 45...

Later EddieO
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Old 06-24-2011, 08:47 AM   #27
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Quote:
Originally Posted by JohnRobHolmes View Post


A crawler motor with more power will wear faster, put simply. Disagree?

Somewhere between 45t and 50t will be where it falls. No need to split hairs and worry about getting it exact until you sit down and actually wind it up.
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Old 06-27-2011, 12:38 PM   #28
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So some nerding on this topic, pertaining to wire gauge and motor wear. As a basic truth, I would state that more powerful brushed motors wear faster than less powerful ones when all other construction is the same. I think we can all agree on this.

Measurements were made through the brushes.

35t handwound, 20ga wire on 4mm web: inductance 17.5 uH, resistance less than the accuracy of the meter- from .6 ohm to .1 ohm
35t machine wound, thinner wire on 4mm web: Inductance 71.2 uH, resistance about 3 ohm

I can use a 35t machine wound all year long with little maintenance. It has less power, but close to the same wheelspeed no load. Under load the speed drops because of the higher phase resistance. After 20 or 30 hours of use it can use a freshening and some new brushes. Enough power to break parts, not enough to pop a gap with no rollup.

The 35t hand wound can run for a few hours before needing maintenance. Depending on terrain this could be as little as 30 minutes before power starts to noticeably drop. It has more power. The voltage drop on the wires is lower because of the lower resistance, thus average wheelspeed will be higher. Plenty of power to break parts, enough torque to pop a gap with no rollup room. You bet I will use it, why else would I have the motor installed?


They are the furthest apart examples, but the construction of the motors are completely identical other than the armature winding. Sure, going from a packed 5mm web to 4mm web may be very hard to notice differences in wear, but the fundamental change of construction will still allow for faster inrush current and higher average power and speed.


My point stands. More powerful motor, more wear. The bench tests only show why there is a difference, real world crawling with high resistance and inductance arms are the proof of service life difference.
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Old 06-27-2011, 03:45 PM   #29
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First off thanks to John and Eddie for their time and info on this. There's some good info on the web but a lot is either incomplete or opinions passed off as fact. I think I've learned more practical info from the 2-3 threads on this site then any where else.

I've got the wire so I'm gonna try a 40 or 45t motor. Probably 45t for the first attempt but we'll see how it goes once it's started.

What brushes would you recommend for a 540 motor and where would be a good place to get them? They don't need to be any thing special just a good all around/basic brush for crawling.

Thanks again guys
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Old 06-27-2011, 03:58 PM   #30
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The basic copper/ graphite brushes seem to be the best all around for crawling. Nice long motor life, plenty of power. It is the same as the old Quasar and is the brush that I and Eddie both carry.
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Old 06-27-2011, 04:09 PM   #31
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Thanks. I've bought them in the past from Tower but their selection is almost none existent now.
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Old 07-24-2011, 03:32 PM   #32
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Hello there
I'm about to buy some wire, and finally if I'm looking for the more "torqy" solution witch one should I choose?

At 27AWG:
=> 201 x 60T = 12060 Total CM ( only 370CM added...)

At 26AWG:
=> 254 X 48T = 12192 Total CM ( only 502CM added...)

As soon as I'll start my rewinding I'll post some pics.
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Old 07-24-2011, 04:20 PM   #33
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Correct me if I'm wrong but...

The 60t would have more torque but the 48t would have more punch with the right gearing.
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Old 07-25-2011, 10:33 AM   #34
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Because of the resistance of the 60t, the 48t would probably produce more torque too unless the voltage were very high. 48t would be my choice.
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Old 07-25-2011, 12:31 PM   #35
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Quote:
Originally Posted by JohnRobHolmes View Post
Because of the resistance of the 60t, the 48t would probably produce more torque too unless the voltage were very high. 48t would be my choice.
So the 48t is more efficient because it's got less wire so takes less volts to max out power correct?
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Old 07-25-2011, 12:45 PM   #36
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Efficiency isn't related to the turns as much as the load and RPM of the motor. It is just that with the slow speed of the 60t, the 60t won't have enough voltage to wake it up. The 48t will indeed take less voltage to max out the power.
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Old 07-26-2011, 03:07 PM   #37
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Now I'm thinking of the proper way to wind the wire...

Starting from the left at the com what would be the best or the right way to do it? The "A" way or the "B" way?


Hope it's clear enough, knowing that the green is for the first stage of winding followed by the second stage (red or yellow) of course from the same length of wire...

So ...

Last edited by Big Pitt; 07-26-2011 at 03:10 PM.
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Old 07-26-2011, 03:41 PM   #38
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I think I get the pics....but not 100% sure what you are doing.....

Now, keep in mind, there are 100s of different patterns you can do on arm, so there isn't necessarily a right way.

Typically you will come down from the comm and start the first turn as close to the shaft as you can.....you then work your way out towards edge of the armature. When you fill it up, you go up right there, you don't cross back over to start by the shaft again, which is what looks like diagram A is showing...

back and forth.........don't wind it like a printer would print a piece of letter.

Later EddieO
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Old 07-26-2011, 05:11 PM   #39
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Your B diagram is how to wind it neatest with best fill.
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Old 07-27-2011, 02:03 AM   #40
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Ok thanks... and they both agree on this one

Waiting fo my wire to arrive.
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