RC Fan Chris

I have 2 lipo's with identical specs: 3S, 25C, 2200 mAh. Just recently, I tried to fly a plane with a BL motor with one of the two lipos when a weird problem came up. When I throttled the motor up, the motor would just twitch a little bit back and forth while making little chirping sounds. The motor would simply not spin normally at all. Everytime I flew this plane before, everything worked just fine. I tried both batts on this plane, but the exact same thing happened. I was thinking that the problem was with the ESC. ESC is rated for 50 A, btw. Kind of overkill. Just to see if the problem was really within the ESC, I tried the batts on a different plane with a BL motor, but the same problem happened.
So either 2 completely different ESC's are acting up, or the batteries started having issues.

Has this happened to anyone, and what's really going on here?

xmech2k

Did the ESC arm properly? What are the battery pack and cell voltages?

RC Fan Chris

I charged and balanced the batteries right before. I didn't check the voltages though.

hayofstacks

Is this a new setup or esc on a old plane/motor? What have you changed recently?

My guess is the timing or the soft/hard start esc needs adjusted.

pmullen503

Sounds more like a bad connection on one of the motor leads. A careful check of the solder joints on the connectors and the connections of the motor windings to motor leads is in order.

xmech2k

Ah yes! Someone's thinking. (Slap's forehead) No I'm not being sarcastic. Good idea!

Cowboy

With this statement, (Just to see if the problem was really within the ESC, I tried the batts on a different plane with a BL motor, but the same problem happened.) I would think that it has to be something to do with the batts. Maybe a bad wire or connection.

hayofstacks

Good point...

How big is the motor? Is it possible its overdraining the batteries?

Its just a bit weird for it to happen on two sepperate batteries at the same time. I'm guessing we are missing a peice to the puzzle.

slipstick

The original post is a little confused but I think you're saying that you have 2 batteries and you've tried both of them on 2 different planes with different ESCs and motors and nothing works correctly. Both motors on the two planes twitch rather than run normally (which would normally mean a bad connection in one of the three motor leads or a bad setting in an ESC).

But if 2 of them do the same thing and they do it whichever of the 2 batteries you connect then you have at least two completely separate problems.

Question: are those the only 2 batteries you can try ? Or do either or both of the motors/ESCs still work normally with other batteries ?

Steve

pmullen503

I missed that the problem showed up on two different planes with the same batteries in the OP.

That would indicate that the batteries are not delivering adequate voltage. When the motor is started the voltage drops below LVC and cuts out. Maybe the charger is malfunctioning?

Measure the voltage of the charged batteries.

RC Fan Chris

Good news. I tested the second plane , making sure the motor to ESC connections were secure, and everything worked perfectly. However, I used a different, older Rx and Tx for this because the newer Tx battery was low. LiPo voltages on both, btw, were 12.5 volts.
So the problem was either the plug connections on the motor and ESC, or the Tx and Rx that I used before.
I'll test the first plane and test the newer Rx and Tx once the battery is charged.

rcers

+1 this is VERY likely your issue.

Mike

vonveska

It happened to me as well. I use Hyperion Titan 80A ESC and Axi 2820/14 motor with 3s 2200 mAh lipos and I am not sure what the problem was but I recalibrated the ESC - switching the Tx on with full throttle and then pulling it down - and the problem seems to go away (so far it's OK).
I also had a wrong setup, because I used a separate Rx battery without removing the middle wire from ESC (the ESC is not opto). Now I added an extra extension without the middle wire (as suggested on this forum - thanks) so maybe this contributed to the problem as well. Another thing I have changed are the batteries - the old batteries were old and their capacity low. Now I use fresh ZIPPYs and I have no problem, the motor is running smoothly.

RC Fan Chris

Update: the reason the first plane's motor didn't turn properly was a loose, corroded soldered connection between the ESC and one of the wires going to the motor. It was resoldered and now everything works great.

So it turned out that you guys were right, the problem with both planes was a bad connection from the ESC to the motor.

Thanks for the help everybody.

rcers

TaDa! That is the first thing I check - more common that you think. I knew when you described the symptoms that was it. But thanks for coming back with the results - helps us to know we are on the right track!

Mike