brushless motor / ESC problems

[Farmer Giles]

Hi,

I'm having a slight issue with my T500 at the moment. When I first spool up sometimes the headspead does not get up to full speed. If I spool down then try again it usually comes back but sometimes it takes a couple of goes to get there.. Once the headspeed is there I flick to IU and it's fine.

I've been through the set up on the ESC again to make sure it's as it should be but other than that I'm not sure and once up to speed I get my normal flight time so I don't think it's a problem with my lipos..

Are there any electrical checks I can do on the motor and the ESC to see if I can tie down where the fault is as the last thing I want is a total failure in flight.. I did have a crash a few weeks ago and I am thinking I may have damaged the motor or ESC but to replace both items with new will cost over £100 so I want to replace the right thing first time.

I could swap with known working items but I don't have access to known working items right now.

any input appreciated

cheers

[JeromeF]

Could be the motor bearings on their way out. Was a comon problem when the kits first came out, I had two die! Not sure if they have resolved this problem or not.

[gazza]

Check your connections from the ESC to the motor are good mate even peel back the heat shrink if necessary and also check the heat shrink where the 3 wires exit the motor. It could have rubbed through. Could be a possible arcing issue I've seen it happen before.

[Farmer Giles]

Check your connections from the ESC to the motor are good mate even peel back the heat shrink if necessary and also check the heat shrink where the 3 wires exit the motor. It could have rubbed through. Could be a possible arcing issue I've seen it happen before.

I know the three plugs are OK but I will check the insulation on the wires..

Ta

[ivor-bigen]

What ESC and motor is it?
Has it only done it since the crash?
do you run it in governor mode?
With two of my ESC`s, when i spool up (soft start) i have to remember to go straight to mid stick (0 degrees) so there is no load on the blades for the governor to settle.
Ivor

[Pipistrelli]

Could you have changed your throttle curve by accident? Worth checking perhaps?

[gazza]

If it's an align ESC then don't use the governor mode for a start as it's rubbish.
Set yourself some throttle curves up

Normal mode 0-60-85-100

Idle up 1- 95-90-85-90-95

Idle up 2- 100-100-95-100-100

Obviously ensure you have the correct pinion for the above too

[leckylee]

i had this happen on my 450 a while ago and i never got to the bottom of it, in the end i put it down to faulty lipo's but thats on the 450. how old are the lipo's, thats interesting what you say (ivor) about the govenor i'll try that on my 500 next time. hope you get it sorted giles let us know how you get on.
lee

[Farmer Giles]

Throttle curves are fine.
0 50 100 100 100 in normal and 100 100 100 100 100 in IU, running 12t pinion.
Lipos are 5S and 4 months old with maybe 25 to 30 cycles in each.
ESC is not in Gov mode, just soft start for helis.

I've just popped the motor out of the heli and had it running in my hand. Whist I was trying it I spooled up and one time it did not get to full speed. I tried moving wires and putting light pressure on the exposed diodes(?) on the ESC and it made no difference. Shut it down and tried again and it seemed fine.

One thing I did notice whilst running it a 100% throttle in my hand it did not run smoothly all the time, it seemed to have a stutter every now and then and moving wires had no influence on the stutter.

One last thing when you plug the lipo in you get the musical notes from the ESC to tell you it's ready to go, well those 'notes' actually come from the motor and they sound muffled now where as before they were quite loud.. Does that indicate some kind of internal winding problem with the motor ??

Bearings seem fine in the motor as well.. no sideways play, just a small amount of end float.

with the things I've experienced I am non the wiser if it's motor or ESC.

Is there a test I can do with a multi meter on the motor to check each winding ?

[GravityKills]

Is there a test I can do with a multi meter on the motor to check each winding ?

there is one, but it's unlikely to yield results here: Check, whether there is a connection between any wire and the motor housing, while the motor is mounted. If so, the mounting screws have gone into the windings.

[Farmer Giles]

I am leaning towards motor TBH as in a crash I would think your more likely to damage the motor with the shock loading rather than the ESC...

[gazza]

Does that indicate some kind of internal winding problem with the motor ??

No mate the beeps just get muffled regarding the position of the magnets in relation to the cooling vents.

Must admit that stuttering doesn't sound good.
Can't you put a multimeter on two of the three wires as you run the motor up and see if you get any sort of voltage output reading and watch it for fluctuations? I've never done it so I don't know but it would discount the motor if you get any voltage changes.

[gazza]

Read here

Stock Align 100 Amp ESC - HeliFreak

[xygax]

The only way to check the ESC is to put a scope on it. that will show if all 6 of the power fets are driving corectly. The muffled bleep may indicate one section isnt driving well. The lack of spool up corectly would also indicate the same thing. I have a stock 500 motor here you can borrow if you need to its a known working one or you can send me the speed controller and i can test it with a scope to prove either way. If you catch them before they really go up in smoke they can be repaired...

Steve

[leckylee]

the notes do come from the motor and not from the esc, and also if the motor is out of the heli they will not be as loud because they ressonate through the frame, that is why if you unplug the motor you will get no tones.

lee