RC10Talk - The Net's Largest Vintage R/C Community

Hey guys,

I was hoping someone might be able to shed some light on this... I'm doing a major rebuild/update on my old RC10 Team Graphite (been sitting for around 15 years) but want to keep an old NiCd/brushed ESC and power setup for "true" vintage racing (there's a guy at my local shop who does the same thing, so I figured I'd give him someone to race against since I already own all the crap). In that vein, I've hit a snag...

The brakes on my P-12 seem to be crap. They're noticeable when making a turn at full lock, but can't hold the car still on a 10° incline (neighbor's driveway). I remember years ago, the brakes would completely lock the rear axle, and if anything were "too" sensitive.

I've re-calibrated the ESC, followed Tekin's instructions regarding how to set the torque, messed with transmitter trims (and even tried only throwing the brakes to about 50% when calibrating it), but nothing has improved. Even using a newer 2.4 GHz radio (HoBao, free from a friend) nothing has changed, aside from the absence of interference and twitchiness.

On another forum it was suggested that a FET may be blown, but the thread quickly fell out of scope due to being in the wrong forum, and admins never moved it... And I'm honestly not a thread bumper.

Anyone have any thoughts? If it is a FET, is it even feasible for a DIY electronics guy to fix it, or would it be better off left in the hands of Tekin? I've got a full brushless setup waiting to go in the car, so I could live for a month or two without it.

Thanks in advance!

Blown FET, or missing/insufficient caps or diodes on the motor-

Charlie don't surf wrote:Blown FET, or missing/insufficient caps or diodes on the motor-

Ah-ha, didn't even think about the caps/diodes on the motor. The ones on there were installed by me as a 12 year old, so they probably warrant further review.

Motor is a Trinity SpeedGems Onyx 14-2. Got any specs/recommendations for this motor, or any resources I should check?

*edit* I do remember there being 2 things soldered onto the motor that don't look like diodes or caps to the best of my knowledge (little semi-translucent green square things). At work, so I'll need to look through photos to provide more info.

Tekin's never used a diode on the motor it is in the case. Only Novak's use an external diode. If I was to make a guess I would day that it is a blown brake fet. If I remember correctly if the heat sinks touched during operation it would blow out the brake fet. It is possible to change the fet. I have another thread telling what fet is used in the Novak T4 that I repaired yesterday. You need to get the correct replacement if it still exists. Unfortunately almost all mosfet look the same but do very different things. I would not bother sending it back to Tekin. The original company was almost extinct and in a bitter lawsuit for almost 20 years. The new Tekin pretty much just got the name and some designs from what I understand.