RX8+2050kV Buggy - Started coggind and doesn't run anymore

[Lauri]

Hi,

I was very happy with the Tekin RX8 + Buggy T8 2050kV setup. I ran 6x10min raceday and got second place overall without running it before the raceday. Felt really smooth, worked really nice!

Today I went training. First 10min was okay. Next run I tried low punch setting but it was awful to drive (2-3 was the setting I think). So I went back to maximum punch again. After that about minute or less later the car started cogging a lot. Didn't accelerate anymore and then went completely dead. Maybe it went crazy just after changing punch back to max - don't remember.

I recalibrated the radio. I factory reset the ESC and recalibrated. I tried it in "pit mode". Without pinion the motor spins to maybe 100rpm max, it doesn't have any torq so with pinion and drivetrain connected it sometimes doesn't spin at all. Leds on ESC go to max, but motor only just spins, slowly. All sensors seem ok, all three leds light when you turn the motor (sensor ok). Without sensor wire motor spins a bit more, but still - with full throttle few hundred RPM and cogs

I did get the 1-3-5 leds flashing error few times. Then it goes away and everything "works" - with full throttle few hundred rpm. And the strangest thing is: I can't change the ESC mode values!

After factory reset I have the stock settings and CAN NOT change them. I press mode and go to motor type. Press Inc - I see the stock motor type (3 leds I think it was). But after pressing Inc more to change the value it goes out of that mode. Led 1 lights up an... well, you can't change ANY mode setting! Can't change the low voltage cut, can't change motor type, can't change anything!

What to do? It seems to be software error. How could I reload/reflash/reset the ESC?

I can check the motor tomorrow. But I think/hope it is okay and rotor is fine (new motor!).

I can use the Hotwire on Sunday. Can I do more low-level reset with Hotwire?

Setup: Xray XB808 buggy RTR 3400g
LiPo: 4S 35C 5000mAh only gets warm after 10min run. Low iR battery
Power: 18A average = 3000mAh spent over 10-11min run
We have below freezing outside, track is under roof with outside temp -2 to +5 Celsius so no overheating. Gearing quite easy (40mph calculated) and motor only 50-60 Celsius after run.

Help - what to do, what to check? Seems to me I need to reset the ESC but I did what the manual stated and no use :(

[Lauri]

Checked the motor and rotor - look like new (they are), didn't notice anything wrong there.

One more factory reset and still not working correctly. When I push the throttle VERY fast the motor spins up few hundred rpm and then rotates more and more slowly and keeps roteting very slowly without any torque - I press throttle 10% or 100%, same thing!

Where's the low-level reset button for ESC ;) ?

[Marvin]

That sounds more like a rotor failure to me (the 'no torque' thing puts me to this conclusion). If it was anything like my rotor failures, there won't be anything visibly wrong with it, until you try and move the magnets horizontally. If they move, it needs replacing.

[Lauri]

The rotor seems ok. No torque means NO torque. I can put 100% throttle and hold it with my hands.

The problems should be within ESC software. I don't think I have rotor failure + software problem at the same time ;) Hasn't anyone had the situation where you can't change any MODE settings?

[kalbien]

Can you hear the motor spinning? if so, rotor is dead.
or is it completely dead?

I would try factory reset with motor disconnected. my little tekin rs pro is able to go to some dead end and if I unplug motor (I guess you have to de-solder it) than I am able to get it back running.

[coolhandcountry]

Does the motor still have strong magnetic force left in it?

[RBMike]

Check your sensor wires & motor wires first but sounds like the ESC failure to me.

[Lauri]

I appriciate the thoughts but I did all those checks myself and told about them in my first post

Now it is clear that the problem is in the ESC. The motor ran fine with another ESC and my RX8 ESC didn't work fine with other motor either!

I even updated the ESC software with Hotwire but really nothing went better. I still can't change any mode value on the ESC! When I try to change the value with INC button it kicks out of that Mode and doesn't change the value... Seems like a software problem to me!

I will be sending it back to Tekin for warranty repair. And I want to thank Randy for some really fast advices I got from him through e-mail on Friday night

[vayhow]

Your problem and the behavior of ESC are quite the same as what happened on my Losi Xcelorin 2100kv BLS combo. It has been returned to Losi but...I have to say, compared with Tekin, their attitude sucks.

[Lauri]

Well... Tekin warranty worked nice. Sadly I had to ship from Europe and got quite a delay because of the holidays. Now the ESC is on my table and seems that Tekin has replaced only the lower PCB. Haven't yet used tested it but I hope it works.

Tekin could only have better warranty if it had some service in Europe too. Otherwise I'm happy and hope not to have any new problems with it anymore.

So it was a ESC lower board problem after about 60-70 minutes of nonabusive use indoors :(

[What's_nitro?]

The lower board is where the "brains" of the ESC are. So any software error can be solved by simply replacing that board. Hopefully it works right when you get to test it.