Amp Daddy, rewinds. Moved out of swap shop.

[Jonathan DeMaria]

Moved this out of the swap shop instead of deleting it fellas. We have to try to keep those threads clean.

How do you get a hold of Don?

[donhuff]

Jonathan,

You found me! Whats on your mind?

[donhuff]

Eddie,

Like Larry sez, that third wire sticking out is what I call the Y connection. In a Y wind, all three leads are joined on "the other end" from the long end that you put your connectors on.

I use to not know how to mash it down with the rest of the wire, but I finally learned how to do that, so they don't stick out like that any more.

And BTW. On a Delta, you will in up with 6 leads sticking out. Then they get twisted together into pairs so that you in up with just 3.

[donhuff]

fweasel,


Send me something that you have burned up. I can rewind most anything, but I do not like to do NEUs, nor TPs as they are just to aggravating to deal with.

It seem that most people are under the impressing that when I rewind a motor, it somehow gains a whole lot of power. This is not how it works at all. In the case of the Aquacraft it is true, because that motor is so weak in stock form and has just a tiny bit of wire in it. I'm able to double the copper content and that makes a difference in power/speed that you can actually see when running it in a boat.

But with most motors, that have a normal amount of wire. Adding more wire, if possible, doesn't usually add any power nor speed to the motor. Just adding copper doesn't equal more power! My limited motors are more powerful because it's a bigger motor stuffed into a smaller case. "No replacement for displacement".

And again BUT, the copper I use has a better / higher temperature insulation on it that the wire that comes in "most" motors. There again NEU and TP both use this same wire. This better wire will allow you to push the motor a little harder and not burn it up, and that's where the power increase comes from. Because electric motors usually make their peak power at 50% of their unloaded peak RPM, straining it a little more makes more power, ie a bigger prop. But you better have your cooling system working good to get rid of the extra heat because the more you strain it, the hotter it'll get.

[fweasel]

fweasel,


Send me something that you have burned up. I can rewind most anything, but I do not like to do NEUs, nor TPs as they are just to aggravating to deal with.

It seem that most people are under the impressing that when I rewind a motor, it somehow gains a whole lot of power. This is not how it works at all. In the case of the Aquacraft it is true, because that motor is so weak in stock form and has just a tiny bit of wire in it. I'm able to double the copper content and that makes a difference in power/speed that you can actually see when running it in a boat.

But with most motors, that have a normal amount of wire. Adding more wire, if possible, doesn't usually add any power nor speed to the motor. Just adding copper doesn't equal more power! My limited motors are more powerful because it's a bigger motor stuffed into a smaller case. "No replacement for displacement".

And again BUT, the copper I use has a better / higher temperature insulation on it that the wire that comes in "most" motors. There again NEU and TP both use this same wire. This better wire will allow you to push the motor a little harder and not burn it up, and that's where the power increase comes from. Because electric motors usually make their peak power at 50% of their unloaded peak RPM, straining it a little more makes more power, ie a bigger prop. But you better have your cooling system working good to get rid of the extra heat because the more you strain it, the hotter it'll get.

Thanks for the additional info. I run TP and LMT motors in the majority of my SAW boats and haven't burned one up yet, but I don't do any oval racing either. If/when I do smoke one, I will definitely send it your way.

[donhuff]

Well, don't send me a Lehner. I can"t do those. And don't send a TP because I don't like doing them. I can do the TPs, but charge $100 to do so. They are not easy and the stator is not coated so I have to do that to them. And for a little more money you can buy a new one.

[Mike W]

Send me something that you have burned up. I can rewind most anything.

Isn't there a strong possibility that magnets have been weakened by the heat and there is no point in rewinding a burnt-up motor?

[donhuff]

I'v not found that to be a real problem. Of the hundreds that I have rewound, only a few have gotten that hot. And usually if it gets that hot, it gets the glue, that holds the magnets in place, hot enough to weaken and the magnets let go and fly off the rotor and into the stator. This usually causes the magnets to break up and destroys the rotor and stator.

If the magnets have been weakened, I can tell it because the motor will have a higher kv than the wind usually produces.

[Mike W]

So the failure that causes a motor to "burn up" is only one where the wire insulation has melted shorting the windings? Any of these can be rewound?

A friend reported a failure in a SAW motor where power is lost and upon inspection it is found the motor lost all magnetic resistance to rotation and spins freely. Have you seen this before? What causes it?

Thanks so much!

[donhuff]

Yes Mike, the #1 failure I see is where the windings get hot enough, either at one particular spot or all through the windings, that the "varnish" on the windings fails and causes a short.

I do sometimes see where one of the leads has made contact with the case where it exits the back. And the wire rubs the case until it goes through the varnish and shorts out.

I have also seen, only a couple of times, where the motor was spun beyond it's RPM limit. And it throws a magnet off.

Bearings can go bad and allow enough slop in the rotor that it can contact the stator.

I had this happen just a couple of weeks ago, but mine did it while holding the motor in my hand and running it on the bench. It ran just fine, then I changed the rotor (TP CM rotor) into another case because the CM rotor can take more RPM and this motor would be turning 70,000+. But the new motor wouldn't run . It just buzzed and stuttered. I spun it by hand, and there was little resistance and no cogging. The rotor had lost magnetism except for the last 1'4" on one end. No idea as to why.

[Jonathan DeMaria]

Don check your messages

[Mike W]

Yes Mike, the #1 failure I see is where the windings get hot enough, either at one particular spot or all through the windings, that the "varnish" on the windings fails and causes a short.

I do sometimes see where one of the leads has made contact with the case where it exits the back. And the wire rubs the case until it goes through the varnish and shorts out.

I have also seen, only a couple of times, where the motor was spun beyond it's RPM limit. And it throws a magnet off.

Bearings can go bad and allow enough slop in the rotor that it can contact the stator.

I had this happen just a couple of weeks ago, but mine did it while holding the motor in my hand and running it on the bench. It ran just fine, then I changed the rotor (TP CM rotor) into another case because the CM rotor can take more RPM and this motor would be turning 70,000+. But the new motor wouldn't run . It just buzzed and stuttered. I spun it by hand, and there was little resistance and no cogging. The rotor had lost magnetism except for the last 1'4" on one end. No idea as to why.

Thanks so much Don!