After being in the hobby for a while and breaking a lot of stuff I thought it would be good to have a motor tester I can use to help diagnose the health of a lot of spare motors I have.  Also I've found in the micro category there is a lot of crap motors out there, or 3 of them are good and one is bad once I receive an order.

I hate killing 4in1 escs just to find this out..

So I put together an old f4 FC with a speedix blheli_S esc and I use a homemade XT60 passthrough adaptor to plug into my DMM for current readings.  Real current readings and not the crap from an ESC current sensor.   I rarely trust those things now.

I can:

• test the motor is actually working
  
• test RPMs as I have RPM filter enabled with JM 15.73 firmware on it
  
• test current draw on 2,3,4,5 and 6S - both the esc and fc are 6S rated
  

I've been going through my old motors and it really does work a treat without having to spend any $$.





Happy with this and it keeps the mind busy when one can't fly atm.

Does anyone else have a home made motor tester?  

The only thing I need to keep mind of is to change the motor pole setting in bf configurator when using RPM telemetry otherwise you will get errors each time the pole count changes on a motor.  Mostly the small micro class of motors need this.

cheers,

ph2t.

OK, I have now tested my stock of spare 5" quad motors, the results are interesting....


ETHIX STEELE Silk V2 (2345kV) Motor 1: 20k rpm = 0.9A
ETHIX STEELE Silk V2 (2345kV) Motor 2: 20k rpm = 0.93A
ETHIX STEELE Silk V2 (2345kV) Motor 3: 20k rpm = 0.97A


HYPETRAIN LE DRIB V2 (2650kV) Motor 1: 20k rpm = 2.02A
HYPETRAIN LE DRIB V2 (2650kV) Motor 2: 20k rpm = 2.07A
HYPETRAIN LE DRIB V2 (2650kV) Motor 3: 20k rpm = 2.15A
HYPETRAIN LE DRIB V2 (2650kV) Motor 4: 20k rpm = 1.85A


DYS SAMGUK SERIES (2400kV) Motor 1: 20k rpm = 1.36A
DYS SAMGUK SERIES (2400kV) Motor 2: 20k rpm = 1.26A
DYS SAMGUK SERIES (2400kV) Motor 3: 20k rpm = 1.41A
DYS SAMGUK SERIES (2400kV) Motor 4: 20k rpm = 1.34A
DYS SAMGUK SERIES (2400kV) Motor 5: 20k rpm = 1.21A

The motors were spun up in BF configurator with an approx reading of 20,000RPM.  It's hard to get exact as the value fluctuates a bit so I tried to match the movement of values as I took my readings.  4S powersource.  What's interesting is how much current these motors need to attain 20k RPM with no load.   Those hypetrain motors really suck the juice.   The ETHIX seem quite efficient.

I could see this a a good test for long range efficiency. I know that they are at no load - the load curve versus current could definitely tell another story of efficiency over the whole throttle range.

Cheers,

ph2t.