Why do AXI motors get so hot??!!

I

iconflyer

Member
Hi,
Just wondering why my AXI2814/22 that are rated at 25amps are getting so damn hot(core is reaching 90 Celsius while casing is staying at around 60-65 Celsius) while only pulling 8amps each. Ambient temperature is 35 celsius and I'm running 14X4.7 APC props. I know I'm over propping this motor slightly but again I'm pulling less than 50% of what the motor is designed for. I'm running carbon bird ESCs at low timing.

Appreciate any advise.
 

Thalios

Thalios

Member
35°C ambiant and 14x4.7 props are probably why. Also, motors are designed to run between 75 to 90% rpm. If you go with bigger props, the motor will spin slower to make the same lift, thus overheating it.
 

I

iconflyer

Member
Well they're not much cooler with the APC-E 13X6.5 props either and I can't use the SF 12X3.8 because they are too small to provide the required lift. Shall I just consider different motors?
 


I

iconflyer

Member
I'm using 4S. On ecalc with the correct pressure, alt, and ambient temperature it's telling me that motors should not get hotter than 55C with very poor cooling...but I assume that means motor's bell and not necessarily the core. with medium to poor cooling it's showing 48C. Both of these numbers are with the 14x4.7's
Here's my setup(motors don't get picked up from the URL for some reason so you have to select 2814/22 from the list):

http://www.ecalc.ch/xcoptercalc.htm...apc_slowfly_sf&diameter=14&pitch=4.7&blades=2


Do you think ESC timing has anything to do with this?
 

R

RotorFilms

Member
iconflyer said:
Hi,
Just wondering why my AXI2814/22 that are rated at 25amps are getting so damn hot(core is reaching 90 Celsius while casing is staying at around 60-65 Celsius) while only pulling 8amps each. Ambient temperature is 35 celsius and I'm running 14X4.7 APC props. I know I'm over propping this motor slightly but again I'm pulling less than 50% of what the motor is designed for. I'm running carbon bird ESCs at low timing.

Appreciate any advise.
Click to expand...

I had the same problem for a very long time, I notice that you are lifting a fairly heavy quad. I went from 14 x 4.7 APC SF to 12 x 3.8 APC SF and with both option my AXI2814/22 motors were cooking to the point where you can't touch them, exactly what you are experiencing now. My solution at the end was XOAR 12 x 6 ( Strange I know as the pitch is much higher, but my reasoning is that the prop is much more efficient than a SF prop and it is much lighter than a APC-E prop ), my motors are now running cool even after some punishing flights for about 5-6min's.

I fly a Cinestar 6 with a 3 Axis gimbal and GH2 all up weight is about 5.5kg.

I know the XOAR's are a lot more expensive but they are definitely worth it. Have a look at this site to see the efficiency calc between the XOAR's and the APC's on the AXI2814/22 motors. They don't have the test for the 12 x 6 XOAR's but I've had great success with them.
http://www.1001copters.com/motor propeller test/AXI 2814-22 APC 12X3.8 4s.htm
http://www.1001copters.com/motor propeller test/AXI 2814-22 APC 14X4.7 4s.htm
http://www.1001copters.com/motor propeller test/AXI 2814-22 xoar 12x5 4s.htm

Best of luck.

Regards,

Andre
 

I

iconflyer

Member
Thanks for the recommendation Andre. I stepped down to my APC-E 13X6.5 and the temperatures went down quite significantly but they're still a bit too high considering the amperage the motors are pulling. I'm trying to find a source for XOAR 13X4 wooden props but no one seems to sell them...I only saw them listed on XOAR's website. Any idea where I can buy them?
 



redridinghood

redridinghood

Member
Same as the plain Xoars. Get a few so you can match the weights of the sets. I am using them on an 7 kilo X8 skyjib for more than a year.
 

You must log in or register to reply here.
Top