Fried Lehner 1940? Help!!! - RC-Monster Forums

Sower · **Fried Lehner 1940? Help!!! -** 06.17.2007, 02:59 PM

Alright, I had my first race at the track today. Actually it was a qualifier and not the main. It was 6 minutes of qualifying and they wet the track down. Well, I made it through to the end but at a heavy cost I'm afraid. The wires from my ESC got so hot that they separated from bullet connectors and the motor was 232. Yes, 232. :036: Now it's totally locked up and won't move.

My setup as some of you know was a Lehner 1940/10 hi-amp, Hyperion 4s 4350, MM, 13t pinion and 44t spur running in a CRT. I've run it on the track before and only on one occasion did it get to 180. And the run times have been about 18 minutes. Today wasn't very hot either.

So I'm guessing it's a loss other than the battery at this point. I didn't check the temp on the ESC, but I'm just assuming. So is there anything I can do? Does Lehner do repairs? And if so, do I have to wait a year and pay for another motor anyway? Any help would be great.

Oh, the good thing is that I finished TQ and the 2nd place guy was 22 seconds behind me. Not bad for a first race, eh? :005:

lxmuff · 06.17.2007, 08:30 PM

Sorry about the motor. Sounds like it was a good day for your personal racing. If you have to wait for a motor, the availability of the Neu motor and performance is really good. Me and another guy totally believe in the performance.

jhautz · 08:33 PM

That seems weird. It doesnt sound like you had it overgeared. Maybe way undergeared???

My calculations are mid 30's for that setup. That shouldn't have been a problem.

But it for sure sounds like a cooked motor. The speed control might still be OK.

Lehner will repair it, who knows what the cost will be. If it was that hot it might be better to just replace it anyway.

That really sucks though. A sweet motor like that down the tubes.

Quote:

Originally Posted by lxmuff

Sorry about the motor. Sounds like it was a good day for your personal racing. If you have to wait for a motor, the availability of the Neu motor and performance is really good. Me and another guy totally believe in the performance.

The MM wont like the Neu though.

captain harlock · 06.17.2007, 09:02 PM

Another guy here fried his 1950, too.......what's going on here?!! aren't they supposed to last for a lifetime?

bdebde · 06.17.2007, 09:06 PM

Yeah, I hate to hear that one fried, after getting one myself. You have my condolences Sower.

BrianG · 06.17.2007, 09:39 PM

Nothing is indestuctable. After all, we are dumping some serious power into these motors so a failure every now and then is to be expected. It just sucks that it happened to an expensive motor!

Sower · 06.17.2007, 09:45 PM

Thanks for all the support guys. Yeah, it does suck, but at least I won! It was a great day for me in that regard. I raced once last year, and this was the first time I raced this year. Otherwise I'm new to the hobby. So I felt pretty good all things considered.

It's definitely a bummer though. I think my next setup will be a 8ight T with a Neu 1521 and either the MMM or the R1MT - whichever comes out soonest and actually works with 6s and a Neu.

Has anyone had experience with a repair from Lehner? Any input on it?

lxmuff · 10:33 PM

My friend and I both use the MM. They don't cog if you gear it correctly. I have posted this info on other forums. People have been buying low rpm/v Neu motors and putting flywheels on them for pinions with the MM. The MM has a hard time getting the vehicle started if it starts out in high gear. We have been using the 1512 1.5D and 1512 2D and a 1512 2D/H using 10-12T pinions with the 46T spur with our converted 8ight and MBX5 buggies.

With todays hot racing day, we seem to get better cooling from the MM by having some drilled holes in the MM TUB to allow the fets on the bottom side of the circuit board to allow some convection. It is the first time we have seen the NUE motor hotter than the MM after a race. Motor 159F with no fan and 143F on the MM with a 30mm fan on the top.

Quote:

Originally Posted by jhautz

That seems weird. It doesnt sound like you had it overgeared. Maybe way undergeared???

My calculations are mid 30's for that setup. That shouldn't have been a problem.

But it for sure sounds like a cooked motor. The speed control might still be OK.

Lehner will repair it, who knows what the cost will be. If it was that hot it might be better to just replace it anyway.

That really sucks though. A sweet motor like that down the tubes.

The MM wont like the Neu though.

aqwut · 06.17.2007, 10:36 PM

that sucks dude.. atleast that motor didn't cost you $600 :)

zeropointbug · 06.17.2007, 10:44 PM

Quote:

Originally Posted by aqwut

that sucks dude.. atleast that motor didn't cost you $600 :)

Yeah, didn't you have a 2230 (or 40?) burn up on you? :002: :eek:

Sower · 06.18.2007, 09:38 AM

Quote:

Originally Posted by lxmuff

My friend and I both use the MM. They don't cog if you gear it correctly. I have posted this info on other forums. People have been buying low rpm/v Neu motors and putting flywheels on them for pinions with the MM. The MM has a hard time getting the vehicle started if it starts out in high gear. We have been using the 1512 1.5D and 1512 2D and a 1512 2D/H using 10-12T pinions with the 46T spur with our converted 8ight and MBX5 buggies.

With todays hot racing day, we seem to get better cooling from the MM by having some drilled holes in the MM TUB to allow the fets on the bottom side of the circuit board to allow some convection. It is the first time we have seen the NUE motor hotter than the MM after a race. Motor 159F with no fan and 143F on the MM with a 30mm fan on the top.

What kind of flywheel are you talking about? Where do you get one, and do you have a photo of yours?

lxmuff · 06.18.2007, 09:47 AM

We use 10T to 12T pinions from century heli with the Kyosho 46T spur. The flywheels are the pinions that I have seen up to 23T pinions and has bad cogging. I don't know how low of a pinion you can go without cogging because we have never had the problem. I think I've heard of people having problems with 16T, 46T spur, MM and Neu motors.

Sower · 06.18.2007, 09:52 AM

I guess I'm not getting the flywheel idea here and how you avoid the cogging with your Neu/MM combo. I assume it's like a clutch, right? Do you have a link to an example or a picture?

lxmuff · 06.18.2007, 10:27 AM

I don't know what you want a pic of. Here is a 11T pinion on a 46T spur with a LOSI 8ight.

http://www.rctech.net/forum/showthre...=158327&page=4

With a larger pinion on the mechanical side, it is harder to overcome the interia of the rotor from a standstill and to overcome the static load of the vehicle.
If you ever drove a manual automobile you coud get the idea of starting your vehicle out in a high gear and seeing that the vehicle will stall or you have to feather the clutch a lot.

On the 3 phase induction motors that these Neu Motor are designed around, it is essentially one magnetic field in the rotor chasing another field in the stator. If they cannot move relative enough of each other, it is like a short(they heat up, the same thing happens too when there is too much "slip" between the fields) and so does the esc for trying to put more load to the motor. That is why the sensored motors work better because it knows the relative position of the rotor while putting the inital power to the motor.

Sower · 06.18.2007, 10:36 AM

Right, I get that part. I guess I was thinking that you were saying there was some kind of additional piece and you were calling it a flywheel. I think I just misunderstood you. If I hear you right, you're simply saying that using a smaller pinion will reduce the resistance on start up. Right? And therefore I would need to use a 10 or 11 tooth pinion and work from there. Am I on the right track?

Thanks for your patience, and nice 8ight by the way! :027: