Blueprinting UL-1 Motor Wires

[properchopper]

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After having several UL-1 motors short out the wires where they enter the endbell ( due both to pushing the motor hard and the low-spec insulation these motors come with), I've taken to "blueprinting" these wires on my own motors. When Stephen gave me this previously run motor for the new Spec FE 30 I'm building for him, I went ahead and began the procedure. You can see in the photos that this motor was ready to go After removing the bullets, I slide 1/8" shrink all the way to the coils, and reinforce with another piece of shrink. " An ounce of prevention....."

[m4a1usr]

Looks good Tony. That guy was headed for a "show down". Polyolefin should work just fine.

John

[properchopper]

The insulation on the motor is stamped " 125 C ". That's 257 deg. F. I don't doubt that, given how hard some of us push these motors that that internal temperature
( not what gets measured with the temp gun on the can after retrieval and untaping) can reach these temps. While I'd like to see a higher (or more accurate) spec on the wire insulation and especially on the stator windings, these are good motors for the money and, realistically, were not likely intended to be pushed as hard as many of us do. Then again, the race goes on.....

[CHIEFY_44]

All i can say is thank you tony

[ray schrauwen]

Thanks Tony!

[jasoncyclone]

Thanks Tony, I will fix my UL1 motor tonight!!!!

[stadiumyamaha]

ive put new covering on my motor wires but never that far in. I will be now. Thanks for the pics showing how you do it

[Chilli]

Is this legal for NAMBA Spec Classes??

[properchopper]

Is this legal for NAMBA Spec Classes??

That's a good question. I'll check.

[Doug Smock]

Man I surprised to see this. Some of the "experts" say these little 50 amp motors will take 90 to 100 amps without damage.

Great idea Tony, I've done it myself on my O/B, because of the possible chafing at the end bell.

Don't let this give you a false sense of security guys. Remember, if you are heating up the motor leads like that, it is possible that there are " spots" in the stator core that you can't see. Keep pushing and you'll find them.

Good luck,
Doug

[properchopper]

Man I surprised to see this. Some of the "experts" say these little 50 amp motors will take 90 to 100 amps without damage.

Great idea Tony, I've done it myself on my O/B, because of the possible chafing at the end bell.

Don't let this give you a false sense of security guys. Remember, if you are heating up the motor leads like that, it is possible that there are " spots" in the stator core that you can't see. Keep pushing and you'll find them.

Good luck,
Doug

Very good point, Doug. Last weekend I had an AQ 1800 quit after some hard test runs on my tunnel. I removed the endbell and the wires entering the stator looked fine but I did the shrink thing anyway. Everything else looked good. Reassembled, bench tested with a 120A Turnigy; cog city & blew my extra cap. ( replaced cap & speedy survived).

What likely happened is that the laquer insulation somewhere in the stator core melted and caused the hidden, internal short. These motors are great when operating within their comfort zone, but won't survive too much internal overheating, and the only way to prevent this is to keep the setup within reason.

Mike raised an interesting point about spec legality. I know that its been an accepted practice up 'till now to replace the stock connectors with 5.5's, but going one step further by "blueprinting" the wires needs to be checked out. I will check it out now that spec ( or P-Ltd.) has changed from a club-level to a NAMBA class.

[Chilli]

I ususally don't stick my nose in NAMBA business Tony. I know the Spec classes are record trials eligible now and don't want anyone to find out the hard way. Some people might have a problem with opening up the end bell. In our district spec classes, we specifically permit any connector on the motor. Thats a great idea none the less.

Is the laquer insulation what causes the whispy oderless white smoke when a UL1 motor gets too hot? I was proped a little hot on one of my UL1 set ups. I would see just a bit of smoke at then end of a heat when I pulled the hatch off and the motor would be in the upper 140's. I dediced to kept the prop on and see how long she would last. She lasted about three race weekends before she died during a heat. It wasn't anything catastrophic. She just quit running during the race. By the time the heat was over, she cooled down where I could bring her in. Upon inspection I could smell the slight burnt electrical smell and see inside the motor that the windings were a little discolored. So I trashed her and proped down just a bit.

[properchopper]

I ususally don't stick my nose in NAMBA business Tony. I know the Spec classes are record trials eligible now and don't want anyone to find out the hard way. Some people might have a problem with opening up the end bell. In our district spec classes, we specifically permit any connector on the motor. Thats a great idea none the less.

Is the laquer insulation what causes the whispy oderless white smoke when a UL1 motor gets too hot? I was proped a little hot on one of my UL1 set ups. I would see just a bit of smoke at then end of a heat when I pulled the hatch off and the motor would be in the upper 140's. I dediced to kept the prop on and see how long she would last. She lasted about three race weekends before she died during a heat. It wasn't anything catastrophic. She just quit running during the race. By the time the heat was over, she cooled down where I could bring her in. Upon inspection I could smell the slight burnt electrical smell and see inside the motor that the windings were a little discolored. So I trashed her and proped down just a bit.

Mike, no prob, I'm glad you brought it up. Could be a "bone of contention" among the race crowd. I hope Brian and Darin weigh in - I respect their judgement and they had a lot to do with the birth of the spec phenomenon and rules.

I've had that "wispy smoke" before and chalked it up to lube smoke or bilge water boiling. Usually when the stator insulation melts it smells - you know that smell !

[Rumdog]

If it isnt legal to reinsulate your wires...... that make this sport kind of a rediculous joke. Really.

[Chilli]

It's just the nature of the class. Spec is a specialty class and specialty classes have funky rules. You should see what the rc car racers do in the spec classes. They are really hard core (sealed motors and motors that are handed out at the race).