Fried Lehner 1940? Help!!!

[lxmuff]

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.

[silentbob343]

Originally Posted by Sower

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?

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.

[Sower]

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.

[captain harlock]

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?

[Sower]

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?

[Serum]

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.

[Sower]

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.

[captain harlock]

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.

[Sower]

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.

[Sower]

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.

[Sower]

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?

[BrianG]

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.