Alternately reversing motor rotation w/LRP ESC

[Coelacanth]

Guys, the first time it happened, I thought I had Alzheimer's or something...but I've confirmed this behavior and wonder if any of you have experienced something similar?

So, I installed an LRP AI Automatic Super Reverse in my Optima. Unlike most ESCs, there's very little to do with the programming; just plug it in and it supposedly auto-senses everything. I did that, giving the throttle a goose with the wheels in the air, and saw that everything was turning in the right direction and I did the full forward/neutral/full reverse to let the unit calibrate itself.

I disconnected the battery and tightened a few screws, put the body on and went outside to give it a test-run. As soon as I press the throttle, it went in reverse! I was like "Wtf, I coulda swore it was going forward a minute ago!" Anyway, I switched motor leads and all was fine.

The next day, I charged that battery up and was out at the lake, thought I'd give it another run. Once again, it was reversed, and throttle made it run backwards. This time, instead of reversing the motor leads, I just unplugged the battery, then plugged it in again...and now it ran in the correct direction!

It seems every time the battery is disconnected from the ESC, the ESC reverses itself somehow. Have any of you seen this behavior?

[dldiaz]

I have been extrememly frustrated with this problem.
I have an AI Automatic Bullet Reverse - top-of-the-line, no motor limit, over a hundred bucks... you get the idea...

The reversing with my ESC is not even as reliable as switching back and forth with on/off cycles - mine will reverse IN THE MIDDLE OF A RUN!!! Yes, I can be running great for 2-3 minutes and all of a sudden, BANG! Forward becomes reverse - it has happened while powering a long at 15-20mph, and WHOA! The damn thing spins out, trying to go reverse!!!


If anybody knows a solution to this problem, please let us know.

-cheers

[Charlie don't surf]

Most likely a faulty motor sensor lead, if a sensored motor is run w/o the sensor wire it can work, but the motor's rotation is determined by the direction is has "sensed". If that same car is to roll backwards on the starting line ( or after a spin ) and you punch it it will run in the direction it "sensed" the motor was moving ( reverse in this case). A bad lead can do the same thing-

[Coelacanth]

Most likely a faulty motor sensor lead, if a sensored motor is run w/o the sensor wire it can work, but the motor's rotation is determined by the direction is has "sensed". If that same car is to roll backwards on the starting line ( or after a spin ) and you punch it it will run in the direction it "sensed" the motor was moving ( reverse in this case). A bad lead can do the same thing-

I don't think that's the case as this is a brushed motor ESC and there's no sensor lead. Just positive & negative.

[jwscab]

it probably has to do with the voltage sagging to the esc/receiver, and when it does, the throttle position is not at zero, making the esc think that 'full throttle' is actually the zero position and then it calibrates all wrong.

thats a tough one, maybe try a stutter stopper, or big cap strapped across the battery leads. I'm not familiar with those esc's, but they sound very touchy.

otherwise, maybe contact the customer service, they might get flooded with calls with the same issue.

[Coelacanth]

It doesn't appear that LRP has any support email, their "Contact Us" page just goes to a German long distance number.

I registered on their forum and posted a topic, at least one other person had a similar issue that seemed to be unresolved.

@ jwscab...I'm not sure about sagging voltage, it happens when connecting a freshly charged battery...

[jwscab]

yeah, i'm not talking about the main high current path, this is more like the battery gets plugged in, stuff starts initializing, the voltage drops momentarily as something get charged or turned within the controller, causing a sag at a specific part of the board, causing a reset. weird anomaly, but I see this type of stuff sometimes, working with microcontrollers and system-on-chip with lots of small traces, etc. we're talking in very brief time periods, microseconds in length during startup. the power supply will basically get a hiccup, and stuff gets in a funky state.

[Coelacanth]

the power supply will basically get a hiccup, and stuff gets in a funky state.

I hear you, jwscab...I've worked with computers in I.T. for 16+ years, I know all too well about PCs having hiccups, and going funky--until rebooting.

[jwscab]

BTW, I never mentioned this before I don't think.....great screen name

[markt311]

Call Team Associated, They do the customer service for LRP in the USA.