Help! ESC problems

[alanrchase]

I now have 7 12A ESC and none of them work. It started with 2 Mr.Rc ESC purchased from an Asia based internet store, continued with 4 EMax ESC and totay another Mr.Rc. They all have the same issue. Throttle calibration does not work as per the instructions. No beeps for battery cell count when plugged in. Motor stops as soon as you input servo movements. Will enter a sort of programming mode after a lot of bother but starts at one long and one short beep. I gave up when it reached one long and 12 short beeps. I am assuming they are counterfeit ESC that may be somewhat ok for multirotor use but are no good if you want to draw power with the BEC. Anyone else having similar problems with 12A ESC?

 

[Merv]

......Motor stops as soon as you input servo movements.....

Be sure to remove the prop until we sort this out.

I have had a bad ESC or two but not 7 bad ones.
So the motor worked at some point? How big is your motor, how many amp is it using?
The beeps don’t come from the ESC, they come from the motor. If the motor is not hooked up, no beeps.

 

[quorneng]

alanchase
How many amps are you drawing from the BEC? It is likely only rated at 1A. Even a 9g servo will draw that when moved quickly even under no load.
As soon as you over load the BEC it is likely to effect the operation of the ESC.

I have no problem using a Ebay cheap 10A ESC with three 3.7 g servos in a light foam airframe, actually an RC conversion of a Cheetah toy chuck glider.
I don't remember calibrating the throttle. It just worked. Many ESCs have auto calibration.

 

[alanrchase]

Be sure to remove the prop until we sort this out.

I have had a bad ESC or two but not 7 bad ones.
So the motor worked at some point? How big is your motor, how many amp is it using?
The beeps don’t come from the ESC, they come from the motor. If the motor is not hooked up, no beeps.

The motor is a 2204. The motor will run ok but as soon as I move the servos (2 x 5 gram) the motor cuts out. I get various beeps but they don't correspond to those in the instructions. I have two other planes with 12A ESC and they work fine. All 7 ESC have exactly the same problem.

 

[alanrchase]

alanchase
How many amps are you drawing from the BEC? It is likely only rated at 1A. Even a 9g servo will draw that when moved quickly even under no load.
As soon as you over load the BEC it is likely to effect the operation of the ESC.

I have no problem using a Ebay cheap 10A ESC with three 3.7 g servos in a light foam airframe, actually an RC conversion of a Cheetah toy chuck glider.
I don't remember calibrating the throttle. It just worked. Many ESCs have auto calibration.

The EMax BEC are 1 amp and the Mr.Rc are 2 amp. The motor fails when I move 2 ×5 gram servos. I have 2 planes with 12 amp ESC one of which has 2 × 9 gram and 1 × 5 gram servos and everything works fine. I have tried various combinations of motor, reciever, battery and servo and all 7 ESC fail.

 

[Merv]

....I get various beeps but they don't correspond to those in the instructions. I have two other planes with 12A ESC and they work fine.....

Are you using a different Rx in the other planes? Are the beeps from the Rx rebooting?

You might be dealing with a bad Rx. You could also try the servos one at a time, maybe one is bad and drawing too many amps.

 

[quorneng]

For 7 ESCs to fail in the same way does suggest that:
Either there is something wrong in the way the Rx, ESC & servos have been set up.
Or, and perhaps even more of a worry, is that something in the set up is actually damaging the ESCs as soon as they are used.

My suggestion is to get a servo tester and work 'on the bench'. Set up an ESC, motor (no prop) & a battery with a servo tester. The radio then plays no part. If the motor runs smoothly up to full rpm then you know the ESC is working.
You then change the set up with a servo to confirm that it moves smoothly over its range when powered by the BEC.
Then do it with both the motor and servo together (most servo testers have multiple outlets). If that works normally then you know the servo, motor & ESC work together and your problem is caused elsewhere.

This is the set up I keep on the bench to test an ESC or a motor and/or a servo.

That servo tester only cost a couple of £s on Ebay.

 

[chrisvdv]

Check all the solder joints between battery, ESC and motor leads. Had the same problem until I opened the joints and found two dry soldering joints. Re solder them and problem solved.

 

[alanrchase]

After looking around on the internet I am coming to the conclusion that the EMax ESC are knock offs. All the components work when I use a spare 30A ESC. I think someone is making dirt cheap ESC that will work on quadcopters that have a separate power board but are useless for use on anything with servos. Makes life difficult as I cannot source them locally. Will probably have to get direct from EMax. Thanks for all the suggestions.

 

[chrisvdv]

Use them all the time. Nothing wrong with them. But I buy from Flite Test store.

 

[alanrchase]

Use them all the time. Nothing wrong with them. But I buy from Flite Test store.

That's the conclusion I have come to. Mr.Rc is a mystery, no info available on them. EMax are a recognised brand and I have 2 ESC working perfectly in planes. Getting them from unknown sellers via an internet platform is a gamble. Live and learn.

 

[TheFlyingBrit]

I have used Mr Rc 12amp esc's in the past on my Tiny trainers using the Emax 1806 motor and 9g servos they worked fine and still continue to do so on my 3ch and 4ch versions.
However, when I built further Tiny trainer models and fitted MT2204 2300kv motors, I used 20 amp ESC's and ended up swapping the battery connectors from JST to XT30's, as the connections kept melting on the JST's after just one flight.

 

[alanrchase]

I have used Mr Rc 12amp esc's in the past on my Tiny trainers using the Emax 1806 motor and 9g servos they worked fine and still continue to do so on my 3ch and 4ch versions.
However, when I built further Tiny trainer models and fitted MT2204 2300kv motors, I used 20 amp ESC's and ended up swapping the battery connectors from JST to XT30's, as the connections kept melting on the JST's after just one flight.

I was trying them on a 2204 1800kv motor whose specs say maximum current is 10A. With the motor at quarter throttle and moving the rh control stick towards a corner the motor immediately cuts out. As I said, pretty sure these are knockoffs as having 7 all fail in exactly the same way on initial use would be very strange.

 

[TheFlyingBrit]

Suggest you check the rating for the MT2204 motor you will probably find your exceeding the amp rating, particularly if your using a 3s battery

 

[TheFlyingBrit]

I am quoting the 2300kv version here but the MT2204 draws a max current of 11.5amps with a 3s battery, you also supply current to your Rx and servos too don't forget, the BEC will apportion some for the receiver and servo operation.
I think its a current overload circuit which is cutting out your supply to the motor, I could be wrong. I wouldn't use anything less than a 20amp on a MT2204 motor.
One way to find out is try it on a 1806 motor the current rating is lower on that motor, or try a 2s battery ?

 

[alanrchase]

Suggest you check the rating for the MT2204 motor you will probably find your exceeding the amp rating, particularly if your using a 3s battery

The 2204 specs say 10A at max throttle with a 2S and 9x4.7 prop. I am having the issues at 25% throttle with no prop fitted with a 2S. I have another plane with an EMax 12A ESC and run a 2206 1500kv on 3S with an 8×4 prop, 1×9g servo and 2×5g servo with no problems.

 

[Bricks]

Just to ask a dumb question working on this ESC problem have you tried starting from scratch setting up a new model in your transmitter rebinding etc, maybe some mix got turned on that you do not know about.

Have you tried different batteries and are they fully charged and checked to make sure they are up to snuff? Could be a low voltage failsafe going off.

 

[alanrchase]

Just to ask a dumb question working on this ESC problem have you tried starting from scratch setting up a new model in your transmitter rebinding etc, maybe some mix got turned on that you do not know about.

Have you tried different batteries and are they fully charged and checked to make sure they are up to snuff? Could be a low voltage failsafe going off.

I have tried 2 receivers, 2S and 3S batteries, 2 motors, combinations of 4 servos and combinations of all of the above. When I use a spare 30A ESC everything is fine. When these 7 ESC don't even "beep" the number of battery cells when plugged in then something is fishy with them.

 

[alanrchase]

An update. Today I recieved 3 more EMax ESC ordered from a different internet platform and all three work as advertised.
Differences between the two.
The good ones come in a pack with a scratch off authentication sticker in the top right corner of the packet.
The good ones have thinner wires for the BEC connector.
The ones that don't work are obviously counterfeit.
Thanks again for suggestions.