Questions on heat

[Dafni]

Originally posted by RC-Monster Mike
You are a special case, Daf!

Yes, I know:p

This heat-issue business drives me crazy. I'm getting fed up with it. I hope the Lehner will do me good.
I'm getting a too-hot motor on 16/72 on a parking-lot, and the driveline is butter-smooth, believe me.

Yesterday I discovered something: On the endbell, where the wires enter the motor, there is this gap where you can see the windings. On my current motor, two threads kinda stick out. Just two single threads are visible, looks like the bundle of windings was broken up. For comparison: on my broken 9L the copper is nicely tugged away. But on this one it looks as thought the manufacturer messed something up. I also notice that the endbell gets REALLY hot. Could it be that I replaced my broken 9L with another bad one??
The motor never popped open, btw!!

OMG, I really hope for the Lehner.

[Serum]

Got a close up pic for illustration Daf?

[Dafni]

Not at the moment, but I'll see to it. Should be able to post something in about 24 hours time.

The windings are bundles of single threads (don't know the proper word) and two of those are kinda sticking out. Looks as if they got clamped in when they pressed the endbell on.

My backplate gets over 100°C pretty quick :eek: Could this also be the reason why my Speedo suffers?

If yes, oh gosh, another damaged motor. That's 2 in a row.

Expect a pic tomorrow.

[RC-Monster Mike]

A damaged motor will get hot and make the controller hot pretty quick for sure.

[Dafni]

Hmm, I'll take a pic tonight.

Is there a way to check if it's actually damaged? Like resistance?
I guess you'll have to admitt my temps are exceptional. (At least that's what I hope) Thermaling controller on 14 cells, even with fans ..... 100°C motor at 16/72 ..... can't be kosher. I have a nice airflow over the setup, and I also tested it on a big parking lot.

But, two damaged motors in a row...:C:

[RC-Monster Mike]

Baffling for sure. My warrior is nearly bulletproof. The motors, well, if a motor or so has issues, I can live with it based on the volume of motors. Two in a row to the same person is a bit of bad luck, though!

[Dafni]

Baffling? Nice word, gotta add it to my dictionary:)

I think the Warrior is fine, no brake fade whatsoever on this one.
I wonder what you and Serum will say on my pics tomorrow. If the motor is bad and overheats my controller I'm glad I found the bug. Getting sick and tired of all this finger-burning issues. I decided to go BL because I thought it's reliable stuff. Let's see.

Mike, what temps do YOU get on your 35mph Maxxes after a full race? Mine are over 190°F after 5mins, whatever gearing I try.

Do you think measuring the resistance between the leads would provide some usefull information?(this may be silly, just an idea)

Bad luck? If it's over now, it's okay. If it continues .... I'm sure I'll find a buyer for my Revoxx.

I wish I could show you my truck and get your opinion 1:1, but at least we have the Net.

[RC-Monster Mike]

I haven't temped my stuff in a while. I touch the motor to make sure it isn't too hot. The last time I temped the motor, it was around 160F after a full race on 18.5 volts (xl2400). I too wish I could see your truck in person! I would love to play with it as well! I hope your bad luck streak is ending as well.

[Serum]

No, a normal multimeter is not able to measure the low resistance, it would not notice if one or 2 of the wires in the litze (don't know the English word either) is broken. That would not cause your problem either, the problem can be that the open wires touch the housing of the motor, so in addition to that;

Here is one thing you can do for sure!

measure the resistance between all three wires and the backplate/motorhousing. It must be isolated, otherwise it will disturb the electro magnetic field and it will heat up pretty quick I think.. The bearing could deliver the power to the shaft/magnet as well..

Did not knew the word either, i was looking for the synonym of 'verbijsterend' in Dutch to English only could come up with stunning.. didn't really liked that either, but i could not find another synonym, Untill........... And there was Mike... ;)

So Daf go home, grab your cam, and the multimeter and MEASURE!

[Dafni]

Well, here it is. It's the closest I can get with this camera. I hope you can see what I was talking about.

The wire (Litze) is not much sticking out, less than one milimeter.
Is this normal? My other motors look different, the windings aren't visible at all.
I think they use a mold or something to press the windings into the can and then they bake it solid. Perhaps something got caught :W:

Serum, thanks for your input. I will check the resistances as you described. Maybe I'll even bring the motor here to the university, were the electronic nerds have their super-equipment.
Hey, I know "Litze", but "verbijsterend"?!? Search me :L:

Mike, 160°F after a full race .... I can only dream of this...:Love:
I will drive my 2400 mainly on 16,? Volt (14 cells) with the occasional 3 extra cells. So this should remove the sweat from my ESC and give me a reliable setup with a motor that should last a lifetime, right?

Bad luck streak? I'm tired of it. Maybe I should light a candle or try some holy water. The worst thing is that the truck would handle great, and my design works flawless, I just want to drive it.
Believe me, if it weren't for this big pond, you would have had a chance to play with it long ago.

Thanks guys, so far. You're a big help. I throw in a dance onna table, but save the real rage of excitement for when I can run one single pack without having to take breakes. :L:

[RC-Monster Mike]

While I can't say for certain the motor is the problem, it certainly has problem potential. If those windings were damaged(scratched, for instance), it would cause the trouble you are having. My fingers are crossed for your success!

[Dafni]

Well, I'll wait for the Lehner, then.