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-   -   What did I break ? (https://www.rc-monster.com/forum/showthread.php?t=10220)

Hypersprint 02.15.2008 11:50 PM

What did I break ?
 
I recently bought a used E-Revo with a 4s Lipo, Quark 125b and a Nemesis 7L motor. When I ran it the ESC and Motor would get to hot to touch, this was only hitting full throttle a couple of times each run since it was a wild ride at that speed. Since a lot of you don't seem to have to much trouble with heat I was wondering if there is a problem with this configuration.

My Big Problem:
The last time I was running I hit the trigger hard enough to flip the truck on its back and when I flipped it over it could barely move. I could hold it in place and hit full throttle and the truck would try to move but could not. I took the pinion off and hit full throttle and the motor would rev up and down at all kinds of different speeds without moving the trigger. The first thing I did was a basic check of all plugs and connections without finding anything obvious. Have you seen this before? How can I test the ESC, motor, battery etc. I'm not new to RCs but I am new to brushless and I am hooked.

Thanks
Rob

ilpufxit 02.16.2008 11:35 AM

Heat-up
 
Sounds like what happened to me when I bought my 8ight. It had been overheated. I could smell the hot electronics smell on the esc, the motor did the same things you're describing. I sent the motor out for service and I was told that it had become de-magnetized from the heat. It was cheaper to buy a new motor. Problem is, the esc may also be damaged. If you have access to another BL motor, I would plug it in and try the esc that way. At least if you have to send it out, you can do it right away. I've had really good experience with S&T (Quark) service.

No one said it would be cheap to play.

rschoi_75 02.16.2008 01:51 PM

ilpufxit, is most likely correct about your motor.

One major concern I see is your motor choice. The feigao 7L (3511kv) on 4s trying to push a revo is not a recommended choice. Most of us that use feigao's prefer the larger XL size cans, since they are more powerful, and can be geared within a wider range.

Most people also choose lower kv motors (2000-2700kv) for 4s duties, since these ranges allow you to stay within Feigao's max rpm limits. The 7L (3511kv) on 4s lipos pushes your motor past 50,000 rpms. The feigao bearings are only rated for 45,000 rpms max. You can buy some 65K rated bearings, which will help, but the motor will still run very hot.

jnev 02.16.2008 02:01 PM

Yah, the 7L is definitely not the motor to put in a Revo. I am actually using the 7L in a 2wd stadium truck which is probably less than half the weight of the Revo. An XL motor would suite you much better.

Hypersprint 02.17.2008 02:36 PM

Thanks for all of your help. with the kind of heat I was getting I had a feeling the motor wasn't right.

Now to get a new motor ordered.

To get what I need from RCM it looks like I need to select the motors labeled as

"Feigao/Nemesis/Wanderer "XL" Brushless Motor"

and select 7XL from the combo box

aren't these 3 different brands? Does it mater which one I get? Do motors usually come with plugs or do I order them separate if I decide to use them? or should I just contact RCM before placing my order?

Thanks Again
Rob

suicideneil 02.17.2008 02:53 PM

Technically they are different brands, but I believe feigao builds all of them. I think you will most likely get a black item, minus plugs on the motor leads. I would say choose either 5.5mm gold plugs (3 male, 3 female), or direct solder to the esc, whichever you prefer...

Hypersprint 02.21.2008 06:55 PM

Thanks Guys,

I got my new motor from Mike today (great service), got it installed and everything runs great and much cooler. Not quite as fast but much more controllable.

Can I get a kit to rebuild my 7L Nemesis that I toasted, or is there somewhere I can send it? I was thinking I might try it in an old JRX2.

Thanks Again
Rob

Duster_360 02.21.2008 09:22 PM

Never seen a rebuild kit, even if offered prob not worth the effort, these are cheap motors. Either buy another new one or maybe try a used one from someone you know or fell you can trust. I bought a used 540c 9xl and had good luck with it, it hadn't been abused much.


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