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

After calibrating a Speed Passion GT 2.0 Pro sensored ESC with a Viper motor it will only run reverse and I don`t know why..

I´ve tried another sensor cable, another motor, calibrate it with the radio in ¨rev¨ instead of normal..

If it were sensorless I would just swap the motor wires, but I can`t because it is sensored.

Any idea about why the motor only runs reverse?

swich your motor leads as it says in the trouble shooting section

http://www.speedpassion.net/uploadfiles/downloads/2010914154017GT2ProLPFGT21ProStock_ESC_User_Manual_Sept14th2010.pdf

He is running sensored tho, and per the same manual it says you cannot change the orientation of the wires in sensor mode

You probably need to change the motor direction in the esc program settings. I would try swapping A and C wires if you can't change direction. Shouldn't hurt anything to try.

Guys, please be careful when recommending things that are specifically warned in the manual- I would hate to see someone try swapping wires and having an expensive issue. Yes, this is procedure on a sensor less but NOT on sensored

That said, have you tried using the servo reversing on the transmitter and recalibration the speed control?

The only time I've heard of successfully changing the direction of a sensored motor (that doesn't have a rotation setting) is swapping A and C, but also reversing the pins of the sensor cable. Caution should be exercised here as most performance sensored motors have built in timing, you'd need 0* timing or a way to retard timing which would advance it for opposite rotation.

None of this is recommended however, and as always if it doesn't work properly straight away - stop.


Edit: reading the manual Jeff posted above it appears you can change direction with the reverse switch. From experience sometimes it works, sometimes not, just depends on ESC. Check forward/brake/reverse operation to confirm that your not using the "reverse" circuitry for "forward"

Note that this is for a sensorless system, but I had a similar issue where the motor only had reverse, and brake. It didn't rotate forward. I discovered the ESC was still set to "Forward/Brake" mode, not "Forward/Brake/Reverse" mode. I doubt if that's your problem but couldn't hurt to mention it, because the symptoms were similar.

Let's not forget that a terminal on speed passion esc may not be the corresponding a terminal on the viper motor. There is no industry standard to insure a goes to a and so forth. Chances are swapping motor wires to check this will do no harm but you should always be careful

Yesterday I tried with a different radio, a KO Propo. And tried also re-calibrating the ESC in `rev` position, but nothing..

After that, since I have a spare ESC (another Speed Passion which I had on my Losi XX that worked perfectly) I fitted the B44 with Schelle conversion kit (the one that was running backwards) with this new ESC, and It also was running backwards. So it makes me think that there is nothing wrong with the ESC`s, I suspect that made something wrong building the B44 with the shorty conversion kit.
But I wonder what it may be..

Added: Looking at the b44.3 manual, I think I know what it is...

Backwards diffs? I thought they normally have a molded pin so you couldn't install them backwards.

RC10th wrote:Backwards diffs? I thought they normally have a molded pin so you couldn't install them backwards.

Exactly, backwards diffs.

In the "little" Schelle manual its says you have to remove that molded pin, but since I didn`t pay much attention to the manual..I made the mistake of leaving the diffs as they were originally.

Thanks to everyone! There was no problem with the Viper motor, or the radio, or anything, it was me
I´m happy now I didn`t swap the motor wires.

Interesting. I guess since you didn't mention anything about the car model, nobody could've guessed the problem.

Coelacanth wrote:Interesting. I guess since you didn't mention anything about the car model, nobody could've guessed the problem.

Yes, I am sure that if I had said it was a shorty conversion someone would have said something like " check if you have build it correctly"..

Thanks !