Fried Lehner 1940? Help!!!
 

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:

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.

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.

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

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

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!

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?

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.

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:

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

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.

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?

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.

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:

Yes. I think a way to put it with the way the MM is with the Neu, the overall starting mechanical resistance is too much for larger pinions.

These motors seem to be the standard for power and keeping lower temps than others. I thought my Plett Maximum was cool, but the Neu has even better temps without the fan and more power.

lol, flywheel=large pinions with lots of teeth. He was jokingly referring to those large pinions as flywheels.

nevermind, I see you got it in your last post.

Sweet. Yeah, I guess since I'd never heard a pinion referred to as a flywheel I was thinking it was some other piece or something.

Why don't you check the motor from the inside and find out the worn out part?
Then you could just ask Mike to send you the parts you need for the motor.
Lehner does have spare parts for these motors, you know.
Or did the winding burn up?

Not sure, but great idea. I guess I don't have anything to lose. I can tell you this - it is totally locked up. Whether that means the winding is burned up or what, I don't know. How would I be able to tell?

I don't know what went wrong with your 1940, must have been some weird binding in the drivetrain or a manufacturer error. This problem is an isolated issue, this is actually the first 1940 i heard of that fried without an ESC problem.

I would open the can (unscrew the end-bell, not easy, but doable if you make some kind of tool that hooks up to the 8 screws the end-bell has) perhaps the magnet 'exploded' perhaps the copper isolation got swollen by overheating.

Yeah, I'll look into it. Whatever the problem, it's a problem and requires a new motor. I'm looking at nl12's Lehner 2240/10 as a replacement. What do you think about that?

I looked at that motor. It's BIG. I believe that it weighs over a pound.

Too big for your application. You're racing and you need a motor that spools up very fast for blistering acceleration. The 2240 is VERY strong, but only if you feed it up with enough cells, and it won't accelerate as fast. Only buy it if you want to make incredible speeds( eventhough, the 1940/1950 is enough for that) get the 2240.

I know it's big, but it's a chance I'm willing to take if it will keep cool under racing conditions. After what happened to my 1940 in a qualifying heat, I'm just really gun shy on going too small. I don't like that it's 6 oz heavier, but I'll do it if it will solve my problem.

The way I see it, I have these options:

Neu 1515
Neu 1521
Lehner 1950
Lehner 2240

The Neu's have the cogging issue, and I'm not sure the 1515 would handle the racing situation based on what happened to my 1940. The Lehner's are impossible to get, but there's the 2240 by nl12 for sale right now with the same KV as my 1940 was. I was happy with that until it fried. Pretty coincidental.

Too big is almost as bad as too small. If the motor is way undergeared, it's going to run hot, which is probably what will happen with the 22 series motor. I'm thinking that you might have a hard time getting enough of a load on that motor in a 12lb truck. My MM and 9XL move a 13lb truck around without problems.

Of course, I've never run one and I'm just guessing.

Hmm, I see. I wonder how much of a load it would need to run efficiently. Am I looking for a "sweet spot" in rpms? I'm using a 4s battery right now.

Sower, I was in the same boat that you are. At first, I figured, the bigger the better; but as I did research I found that this was not true.

Although the better motors can stand undergearing better than the cheapie motors, the general rules still apply. If you undergear it, it will run hotter. What I am concerned about with your situation is that you may not be able to gear it enough to put a proper load on the motor. If you do gear it enough, you might just start breaking things on your truck.

As I said, I really don't know as I've never tried it. I just might turn out to be a great choice, or it could turn out to be an expensive lesson. I have heard of a few guys going to the 1950 and have had success with them, but I don't know how they were running them. Bashing success doesn't necessarily mean success on a track where the running is hard and constant.

I know that you are concerned because you just blew up an expensive motor, but I still think that you should not go wrong with what we know works. With your 12lb truck, it is likely that a 1940 or 1950 will do in a Lehner and for a Neu, the 1515. I just went with a Neu 1512 in my 10lb truggy and all seemed as though it was good.

Right. Well, that's great input - thanks. All I know right now is that my 1940 ran great but it just had too much on it. I felt it was geared pretty good but just not enough of a motor for a race situation. I'm starting to think that for the racing I'm wanting to do the load needs to be taken up by a motor like the 2240. I'm still keeping an open mind, but that's what my gut is telling me.

Anyone else have any insight?

Well, I thought that I was underloading the MM motor in my CRT.5 but it turned out it was overgeared. And further evidence shows that it really needs a larger motor for better temps even though the thing is so small. This seems to contradict with what AAngel is saying, but I've also overgeared a 10XL (Revo) and it ran fine until I put that silly CD in there.

Hey, I've been searching for somebody who would do me a favor and try out the Kontronik Mambo for me. Will you buy that promising motor and tell us how well it's working for ya. It's only for $220, not that much you know. A bit shorter than a 1940, though. It is considered a highend motor, that's for sure...:)

Brian, I was thinking about the .5 tonight. I know it's a light truck, but it still has the 1/8 scale drive train, so to speak. I wonder how something like an 8L will perform in the .5.

captain, I don't know. I've been looking around for a 600-18, but it's kind of pricey. At $220 it's even more pricey. Although I had trouble with my Neu, it's likely going to turn out ok in the end and I think that the Neu will be a better motor. I got the 1512 1.5Y and I paid less for it than the price of either of the Kontronik motors.

Still, curiosity might be the better of me.

As of right now I'm leaning heavily towards the 2240. I will decide tomorrow. :027:

I looked at the Kontronik motors again and noticed that they have a stainless steel can. Is that good? Stainless steel sucks at conducting heat.

Yea, SS is not a great thermal conductor. But as long as its thin it should be no big deal. The other negative is the glued end bells like the feigaos.

I guess ill see. I found a 600-18 for 130 so I figured what the hell. You guys cost me to much money. ;)

Where'd you find that? I'd get one at that price. If you got it from a vendor, please post or PM a link.

I'm planning to get the Mambo-17 for my SuperMaxx. If it pulls the truck around with ease at 25.2 volts without heat issues, I guess we have a winner. The Mambos are FUN600 motors with finned aluminum cans.

espritmodel.com had it.

It was listed as $149 then slashed to 130. I bought it and then it said out of stock. Yesterday I looked and my order status was shipped and its not listed on the site any more. I musta got the last one he had.

Ok, so some people have said the 2240 will be too big and that's almost as bad as too small. My question is . . . what would be the perfect situation to run the 2240? Would it be 5s, 6s, 8s . . . ? I just want to know what I'm looking for so I can make my decision. Can anyone help me on that?

Thanks!