Trex 500 fried esc and bent pinion?

[DannyH]

Have a trex 500e, the plastic head model with the align 500mx and 70 amp align esc. It has done less than 40 flights and has not been crashed (not yet at least ).

The esc started screeching on spool up the other day and then power dropped to nothing. It seemed to have lost its esc settings so reset and it worked fine for a couple of mins then died again. Tried to spool up one more timeand esc starting smoking.

Ordered new esc but took the motor out and the pinion appears out of shape when spinning the motor. new 13t pinion ordered too.

Is it possible to bend a pinion without crashing and could this have killed the esc?

Cheers Dan

[GIXERMAN]

your sure it wasnt motor screeching! i would check bearing in motor by the sounds of it

[Gixxer]

Sounds like a bearing or the motor shaft bent

[DannyH]

I found a spare pinion and tried this morn. Seems to spin straight when mounted back in the heli.

Checked the motor and there is a small amount of movement up and down but none side to side. It also turns smoothly, not notchy.

Guess won't know for sure until put an esc back on. Do u reckon it's worth changing the bearings and shaft out just in case and is this difficult to do?

Alternatively if I get a replacement motor do most people go scorpion or stick with the mx? Until this point have been v happy with it.

Cheers Dan

[DannyH]

The noise almost sounded like a slipping 1 way bearing but when checked it seems to be ok

[bpgoa]

Just an idea for you. If you get a bad solder joint or broken wire between the ESC and the motor then the motor jumps back and forth making a hell of a screeching sound. To the ESC this looks almost like a dead short and will fry the ESC in a matter of seconds. before putting this back into the Heli, use a multimeter to check that you have connections across all three phases of the motor

[Audi_TT 83]

Just an idea for you. If you get a bad solder joint or broken wire between the ESC and the motor then the motor jumps back and forth making a hell of a screeching sound. To the ESC this looks almost like a dead short and will fry the ESC in a matter of seconds. before putting this back into the Heli, use a multimeter to check that you have connections across all three phases of the motor

thats a very good idea, if the motor is "single-Phasing" it can sound pretty bad coupled with a loss in power. does anything get hot ?

[bolders]

Have a look at his post there are some good tips for dry testing a motor to check if it is electrically ok

"Dry Testing" brushless motors (Update Sept 10 2008) - WattFlyer RC Electric Flight Forums - Discuss radio control eflight

[DannyH]

Thanks for all the input, I checked over it with the multi meter and all looks well, so have replaced the pinion and put a new esc on (second hand but working fine).

Did a quick spool up and test hover in the back garden and seems to be working fine. No weird noises or smoke ( yet lol) Keeping my fingers crossed its sorted now and will have a fly after work tomorrow

only negative is the new esc is the 60g one rather than the 70amp but if it works I am happy.

[bpgoa]

Glad it's working for you.

Maybe there were dry joints ESC side?

Have fun