Feigao 7L, Warrior 9920 + 12 GP 3300 cells = hot?

Hi,
I've got this setup (Feigao 7L, Warrior 9920 on 12 GP 3300 cells) in a 1:8 buggy.
I get controller temps above 80C° (176F) and motor temperatures of about 80C°.

I wouldn't worry too much about this if nothing strange happened but I regularly lost control over the car.
Throttle didn't work at all and steering seemed to work sometimes, but without real power. Wheels turned some degrees on ground, lifted up they turned pretty slow.
Servo: HiTec 5945MG.

Do you think the reason might be thermaling or might the Graupner XS-6 have some problems?

I think it's the controller though since the problem seems to occur after driving for a minute or two and then regularly. After a short amount of time (ranging from seconds to a minute) the car is drivable again.

Bye,
felix

[RC-Monster Mike]

With normal 1/8 buggy gearing, the 7L motor is on the hot side if you ask me. The 10L is the better choice for that application. 176F is pretty warm on the controller(near the thermal mark), which is likely due to the hot motor. Perhaps you are thermalling and the temp drop below the thermal mark by the time you get a temp on it. If the throttle stops working, it is most likely a thermal shutdown on the controller. Add a fan and drop a couple teeth on the pinion (or get a slower motor for this application). The steering servo sounds like it is bad, based on your statements. Doe sthe steering servo work well at first, or is it slow from the start of the run?

[Serum]

Mike, your loosing it.. ;)

Give the guy a warm welcome..

Hi Felix! Welcome to this Forum!

Do you use the controllers BEC? what is your gearing end ratio? I guess the only gears that are on the car are ; pinion/spur and diffpinion/ringgear? and how much does your car weight? a good 8.5-9lbs?

I would use a motor in another kv range.

Hi,

the HiTec is fine as far as I can tell. It's working at normal speed and turns the wheels without problems while standing still. Just happens in combination with the throttle problem.

I knew that the motor is really hot, I didn't know that it's too hot. ;)

The buggy is a GS Storm, the new parts are made of carbon fibre.
Some pictures can be found here
http://www.cx4.de/rc/storm01.jpg to http://www.cx4.de/rc/storm08.jpg

Most of them aren't too good, but you get a better idea.

I'm using BEC and the pinion (module 1) has only 13 teeth. So that's pretty low already. The car should be pretty light, about 2.8kg without batts I think..

I'll try to get some more info about the gearing.

[RC-Monster Mike]

I did send a welcome private message, but your are right. welcome aboard, felix. Please pardon my manners. :)

13/46 is still too tall with that motor. It equates to a near 60 mph speed, which is a lot to ask of a 12 cell brushless setup. If your buggy weighs just over 6 pounds with the batteries, I will be impressed. I would guess closer to 9 pounds with batteries.

[Serum]

Mike has got a 12 tooth. (or even a 10, if you don't use a metal spur)

That spur looks rather small, but i might be wrong though..

No problem Mike, I got the private message. ;)

If the spur is the gear next to the pinion it's 48 teeth delrin I think.

I'm not really sure what would be the best way to solve the problem. Higher voltage would need a bec unit (more cables) or a receiver batt, a slower motor would be slower ;).

Would the MGM 120 help?

Changing the pinion might help, but if the 13t pinion gets the controller to 80C° in less than 2 laps it might not be enough to change the teeth count by 1 or 2...

bye,
felix

[RC-Monster Mike]

How fast do you need it to be! It should easily beat the nitro buggies with a 10 tooth pinion, and will run a bit cooler as well. 3 teth on the pinion will make a significant difference.

Dropping down to 10t would do something.

Problem is, I'm in Germany and if stuff gets stuck in customs it's a big hassle to get it.

Do you think adding a receiver pack would help?
Apparently the BEC in the controller produces some heat which could be the reason for my problem.
I don't like adding another battery too much, but it'll be interesting to check if it helps.

[Serum]

Get a UBEC! lightweight alternative!

Well, UBEC wants me to solder connectors to the batt cables and so on, we'll see.

Just found this:
http://cx4.de/rc/warrior1.jpg
http://cx4.de/rc/warrior2.jpg
http://cx4.de/rc/warrior3.jpg
http://cx4.de/rc/warrior4.jpg

Was looking for the jumper to deactivate the BEC...

[Dafni]

I 2nd that! Get an UBEC. Might solve some problems.

Mike is very good at filling out the custom forms, by the way. Never had any problems with his stuff, and the swiss custom guys can be a real pain.

[Dafni]

You got there first!;)

The UBEC is very easy to install, though.

Those pictures doesen't look to nice, man. Guess you found your problem.

[Serum]

Looks like an overload.. might be the regulator for the BEC that does this.. though your motor is way to hot for this setup..

Heatsink melts away pretty easy, but it might be damaged. (the controller)

Just checked the manual, it says the Warrior thermals at 110C°. ;)

Found a 10t Modul 1 pinion in a shop here, I'll try that one.

Can you give me some advice where to find the BEC jumper?
I think I found it a bit under the red jumper and caps. Pretty hard to find with the heat shrink on.