Align ESC very hot at zero load - RC Groups
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Sep 19, 2005, 12:01 PM
Registered User

Align ESC very hot at zero load

I just finished my trex build. I'm using a TP2100 3s LiPo, Align ESC & 420LF motor (from Combo kit), Electron 6 ch rx, HS56HB servos and Eclipse 7 TX.

The first time I plugged in the battery, attempting to get servos to center the ESC became hot in a matter of 10-15 seconds. The motor is not currently connected to the ESC, but the leads are protected from each other.

I've read that the Align ESC does run hot, but what is normal operating temp? Mine was almost too hot to touch - just moving the servos around for a few seconds. The tail servo, HS50, is humming quite load - is this a clue?

Any ideas?

Tired of building... ready to fly,
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Sep 19, 2005, 12:11 PM
Registered User
HS-50 issue, make sure you don't have some sort of digital setting on the gyro on. ON the speed control, I really don't know. See if anyone else does??
Keep'em Flying,
Sep 19, 2005, 12:51 PM
Registered User
Tintin's Avatar
I use 2 35A Align ESC's in my V2 and my XL (and a 25A in a depron plane) none of them gets so hot I cannot keep my finger on them indefinitely even after flying as hard as I can. (which I'm sorry to say does not include 3D, yet ) None of them gets noticeable warmer than room temp if I just check servos, so doesn't seem normal.

What gyro, Nick's idea is the only one I too can think of that would draw that much current when motor not connected, except from a short circuit of course...if a Futuba set to DS (digital servo) it will make a HS50 work it's pants off.

Maybe an idea to make yourself a 0 0 0 0 0 throttle curve when checking pitch, dunno if it makes any difference tho.

Btw, slightly misleading to say hot and zero load, obvious it's got a load, just not from the motor.
Sep 19, 2005, 01:45 PM
My Align is starting to have problems with heat after one month of use. It gets very hot after 6 minutes in flight, causing monentary power shut down. Starting to think 25 amp esc is not enough for the align motor.
Sep 19, 2005, 02:48 PM
FPV Enthusiast
martinic's Avatar
Doesn't the ESC have to give off energy as heat if it has no motor load? If so, then connecting a motor and drawing off current should allow the ESC to deliver power instead of heat.
Sep 19, 2005, 02:59 PM
CD-ROM Junkie
Art Newland's Avatar
You want to make sure no servos are binding or trying to push/pull farther than the linkage will allow.
Sep 19, 2005, 04:36 PM
Registered User
Tintin's Avatar
Originally Posted by martinic
Doesn't the ESC have to give off energy as heat if it has no motor load? If so, then connecting a motor and drawing off current should allow the ESC to deliver power instead of heat.
It will only create heat if current is flowing and I don't think it is unless the motor is attached. Your not running the motor current thru the bec just because the motor is not attaced.

atrr, have you changed pitch/throttle curve on the way.

Main problem when they get warm is of course overload, extra load can be caused by a too tight tail belt, unbalance, too high pitch, too high throttle, blades not tracking, bad bearings, too tight motor/gear mesh and probably more. Any of these changed on the way?
Sep 20, 2005, 02:43 AM
The return of the spity
spityman's Avatar
I agree,

I have a Trex with a 25Amp ESC (Phoenix) and it was running really hot with the stock 2800Kv motor.
I tried to upgrade to the 3200, and after 30secs of flying, my ESC cut out and blew. All the componebts moved on the circuit borad of the ESC with the rough landing too.

I am trying a 35Amp ESC (align) and only using a 2800Kv, and am going to check the results soon.
Sep 20, 2005, 03:21 AM
Registered User
Tintin's Avatar
To be specific I use a 35A non gov with an Align 2800kv and a 35A with gov with an Align 3200kv and none is anywhere near a heat problem doing sportsflying or hover. It has been warm before, before I learned to adjust proper pitch, had bad tracking and a bent main shaft....

Seriously, before writing off any of these esc's for sportsflying, check your heli thouroughly, I'm pretty sure in most cases it can be solved by other things than changing esc.
Sep 20, 2005, 03:25 AM
Registered User
I'd be careful that you're not looking at the wrong thing. There are TWO power supplies in an ESC: the motor and the BEC. Supplying lots of servos (four + gyro) while needing a large drop in volts because you've got a 3S LiPo and radio needs 4.8V is asking too much from many BEC's.

Add-on switchmode BEC's can supply higher currents, and are not neccessarily big or heavy or expensive:

If in doubt, use a piggyback specialised BEC, or a small receiver pack.

Or check the current draw:

Same goes for the motor: check the current draw with a Wattmeter or any of the many similar products.

Sep 20, 2005, 03:27 AM
Registered User
Originally Posted by Art Newland
You want to make sure no servos are binding or trying to push/pull farther than the linkage will allow.
Yes, these will drastically increase servo current draw.

Sep 20, 2005, 03:29 AM
Registered User
Another note as I read more: If the tail servo's humming, it's either binding and trying to reach a position it can't, or the Gyro's overactive (reduce gain?). Both increase servo current draw, which will make the ESC hot.

Charlie (again)
Sep 20, 2005, 04:21 AM
Registered User
Tintin's Avatar
I do agree on all your points Charlie, the bec is made for 3 servos on a 3S pack so it can definitely be a bit small.
However for the bec to get as warm as described when just testing servos on the ground, something is definitely off. It's not just the servos and gyro pulling too much if everything else is in order.
As said I fly 2 helis with an esc that I believe have the same bec and I have no problems with overloading this whatsoever, flying or on the ground. So instead of rushing into a bec and maybe camouflaging the real problem, one should locate the real problem and fix it. I even use 3 servos on the cyclic of the CDE that are more powerful than the HS56.

So 1st step would be to check for binding, check gain and if gyro set for digital servo if such switch exists on this gyro.

Even powering 4 servos with no load and a gyro shouldn't be a problem on the ground as lot's of people manage the same in the air under load with this esc.

So yes a bec might be a good thing when moving to advanced flying but not needed just to test servos, that's not normal with this ESC. Have tested the same one so I'm sure it's not a problem unless it's a faulty esc.
Sep 20, 2005, 06:57 AM
Registered User
Thanks for all these ideas. I will work on it tonight and let you know the results.

I am using the Futaba 240 gyro.

Sep 20, 2005, 08:41 AM
Registered User
Tintin's Avatar
Then you can forget abt digital servo problem as far as I know...

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