Turnigy CA120-70 8600W Brushless Outrunner (100c eq)

HumboldtRc said:
No one has any time to make a few measurement of the size of stator and magnets....?

Please, someone who has one in hand and already has taken apart please measure it... thanks
Click to expand...
My motor is in pieces a.t.m.
I remember the magnets are only 30mm long. There would be enough room int the motor to put a 40mm stator in it.
I haven't measured the stator dimensions yet. I'll try to do it tonight.
-Olaf
 
olaf-lampe said:
HumboldtRc said:
No one has any time to make a few measurement of the size of stator and magnets....?

Please, someone who has one in hand and already has taken apart please measure it... thanks
Click to expand...
My motor is in pieces a.t.m.
I remember the magnets are only 30mm long. There would be enough room int the motor to put a 40mm stator in it.
I haven't measured the stator dimensions yet. I'll try to do it tonight.
-Olaf
Click to expand...

Sweet, thanks for the info.
 
olaf-lampe said:
I rewired the stator in wye and installed the skirt bearing again. Without the skirt bearing the bell wasn't running very well. The shaft bearings are from thailand.
I expect a kV of 150/1.7= 88.
Ri should be 15mOhm.
The new no load currents are:

13.8V => 4.4A
46V => 8.2A @ 4000rpm
Click to expand...

do you mean 8.5mOhm?
 
toolman2 said:
olaf-lampe said:
I rewired the stator in wye and installed the skirt bearing again. Without the skirt bearing the bell wasn't running very well. The shaft bearings are from thailand.
I expect a kV of 150/1.7= 88.
Ri should be 15mOhm.
The new no load currents are:

13.8V => 4.4A
46V => 8.2A @ 4000rpm
Click to expand...

do you mean 8.5mOhm?
Click to expand...
Actually not.
We found out that the motor has 4.8mohm in delta. That means it has 3x the resistance in wye ( hence 15mohm ) but the kv drops only factor squareroot(3)~1.7
-Olaf
 
HumboldtRc said:
I just noticed that they changed the specs. It now says "20v Non Load Current: 11A" so 220 watts to spin is not that bad.... Way better than 17amps no-load current.

http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=14427
Click to expand...
11 amps @ 20 volts is rediculious!
 
Arlo1 said:
HumboldtRc said:
I just noticed that they changed the specs. It now says "20v Non Load Current: 11A" so 220 watts to spin is not that bad.... Way better than 17amps no-load current.

http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=14427
Click to expand...
11 amps @ 20 volts is rediculious!
Click to expand...

yes indeed, it does sound bad.

but rpm/amps wise i think the colossus wont be much different, and i think its just how it is when the diameter is this big, its the (very roughly) 100kph magnet past stator limit thing that ive been banging on about.
and actually its more like the number of poles past stator that matter and this motor has 24 mags making the the count (and surface speed) very high even at only 4000rpm, between this and maby 5500ish rpm (without extra cooling) would be all you would want to get to with this and the collosus in my opinion.

also the (way too high) 150 rpm/volt of this motor makes the situation LOOK twice as bad, so dropping it to 87rpm/volt with wye is the go.
dont get me wrong though, still plenty of power to be had though.
and is there an advantage in the low rpm and high torque area by having heaps more magnets? there must be a good side to offset the above costs in rpm limit??
 
olaf-lampe said:
I rewired the stator in wye and installed the skirt bearing again. Without the skirt bearing the bell wasn't running very well. The shaft bearings are from thailand.
I expect a kV of 150/1.7= 88.
Ri should be 15mOhm.
The new no load currents are:

13.8V => 4.4A
46V => 8.2A @ 4000rpm
Click to expand...

Hi toolman2,
exactly what I did and the no_load current results are much lower.
-Olaf
 
toolman2 said:
Arlo1 said:
HumboldtRc said:
I just noticed that they changed the specs. It now says "20v Non Load Current: 11A" so 220 watts to spin is not that bad.... Way better than 17amps no-load current.

http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=14427
Click to expand...
11 amps @ 20 volts is rediculious!
Click to expand...

yes indeed, it does sound bad.

but rpm/amps wise i think the colossus wont be much different, and i think its just how it is when the diameter is this big, its the (very roughly) 100kph magnet past stator limit thing that ive been banging on about.
and actually its more like the number of poles past stator that matter and this motor has 24 mags making the the count (and surface speed) very high even at only 4000rpm, between this and maby 5500ish rpm (without extra cooling) would be all you would want to get to with this and the collosus in my opinion.

also the (way too high) 150 rpm/volt of this motor makes the situation LOOK twice as bad, so dropping it to 87rpm/volt with wye is the go.
dont get me wrong though, still plenty of power to be had though.
and is there an advantage in the low rpm and high torque area by having heaps more magnets? there must be a good side to offset the above costs in rpm limit??
Click to expand...
No I have video of collossus at 96 volts using 17 amps thats way less!
 
indeed arlo, i was blown away by the video you speak of, dont remind me :D
to be fair though we should have the kv (or rpm really) of both motors similar for a comparison, so olafs fine test with this motor in wye (at about 87kv) with 46v and 8.2amps is looking more similar -ish for these two motors.
remember arlo i patiently await the rpm readings from that 96v run in your vid, as any more than 5000-6000 rpm for either of these motors in my opinion would be troublesome, and require timing changes to achieve.
even 17a at 96v idleing (1632 watts to motor heating without load) means you need 32.6kw of power from the motor to achieve even 90% efficiency, so its asking a fair bit.
 
I've had the sensor location make a big big difference in no-load. Like 2amps to 8amps on the same motor from a teeny tiny nudge in sensor position, and going from neutral to retarded timing seems to lower no-load, sometimes substantially below no-load, like by more than the drop in rpm would make you think it would drop, which tends to confuse me. lol

This is the importance of of somebody out there finishing up a controller brain with active timing adjustment, or Burtie finishing up the magic box that advance/retards timing by RPM and throttle position. :)
 
toolman2 said:
indeed arlo, i was blown away by the video you speak of, dont remind me :D
to be fair though we should have the kv (or rpm really) of both motors similar for a comparison, so olafs fine test with this motor in wye (at about 87kv) with 46v and 8.2amps is looking more similar -ish for these two motors.
remember arlo i patiently await the rpm readings from that 96v run in your vid, as any more than 5000-6000 rpm for either of these motors in my opinion would be troublesome, and require timing changes to achieve.
even 17a at 96v idleing (1632 watts to motor heating without load) means you need 32.6kw of power from the motor to achieve even 90% efficiency, so its asking a fair bit.
Click to expand...
Well its realy simple if its a 75 rpm/volt motor it would be spining 75 x 96 = 7200 rpm! If it was spining much less it would be a load holding it back which meens thats amps would be through the roof!
As for your request I CAN'T I have nothing to run the motor with anymore last time I went to test it with the new ceramic bearing I blew my methods 18 fet!
I am almost done my 24 fet but I can't risk my only controler on it!
I have 2 6 fet bords and 2 collossus motors but I am way behind on work! I am planing to give one motor and maybe one bord to luke for all his help but he is also a very buisy guy!
 
liveforphysics said:
I've had the sensor location make a big big difference in no-load. Like 2amps to 8amps on the same motor from a teeny tiny nudge in sensor position, and going from neutral to retarded timing seems to lower no-load, sometimes substantially below no-load, like by more than the drop in rpm would make you think it would drop, which tends to confuse me. lol

This is the importance of of somebody out there finishing up a controller brain with active timing adjustment, or Burtie finishing up the magic box that advance/retards timing by RPM and throttle position. :)
Click to expand...


Like you said, the motor controller and hall effect position really have a lot to do with the no-load current.

The best way to get the true theoretical performance characterisitc if the motor is to determine the no-load torque of the motor. The easiest way to do that is to build a motor mount which is free to rotate and have a scale on it so you can measure the torque on the motor, then use another motor to spin the motor you are testing and measure the torque and RPM at various speeds. That will tell you the core and windage losses. Then with the phase resistances you can easily build up a model of total loss vs speed and torque. With these little motors where temperature change in the copper is pretty significant, you can even add in the temperature effect on resistance in the copper pretty easily. If you do it that way, you will know the best possible performance of your motor, and will therefore know if your controller / hall setup is bad and worth tweaking, or weather you really have optimized your system.

-ryan
 
Hi,

I'm just wondering what thrust this will produce. Motocalc is of no help here; too large of a motor :roll:

Reviews say 65lbs on 10S, but this motor is rated for 18S!

If it is at all efficient, "20+hp" should equate to more than 100lbs.

Any ideas/help? For those of you who have one, maybe some numbers on 15 or 18S would be nice :cool: :D
 
homer said:
Hi,

I'm just wondering what thrust this will produce. Motocalc is of no help here; too large of a motor :roll:

Reviews say 65lbs on 10S, but this motor is rated for 18S!

If it is at all efficient, "20+hp" should equate to more than 100lbs.

Any ideas/help? For those of you who have one, maybe some numbers on 15 or 18S would be nice :cool: :D
Click to expand...

I fed drivecalc with the statordata and it came up with a peak current of 430A in delta. This and the fact that the torqueconstant kt=1/kv will help us to estimate a theoretical torque limit. 430/150=2.8Nm
I'm interested to see what the experts say...
-Olaf
 
How would this perform with 6s? I'm thinking in using it in a quadocopter... 6S?
 
homer said:
How would this perform with 6s? I'm thinking in using it in a quadocopter... 6S?
Click to expand...

On 6s you would have 3000 rpm. If that is what you want to directly drive four props,you'll be fine. Controllerwise I don't see a problem, since the startcurrent with props is quite low.
The only issue could be the control loop for steering. Don't make it respond too fast, otherwise huge currents kill your controllers.
Four smaller colossus' 7kW with the same kV would suit the task better and it's far cheaper. ( my 2c)
-Olaf
 
homer said:
How would this perform with 6s? I'm thinking in using it in a quadocopter... 6S?
Click to expand...

I hope this quadcopter is capable of flying to the moon... :mrgreen: Super overkill.
 
Miles said:
Hi Olaf,

You forgot that the Kv is not in radians/sec :wink:

I make it 27.4Nm @ 430 amps
Click to expand...

whilst your at it with the correct maths miles, is it right to say at 4.8mohms that: 430 squared times .0048 =887.5watts of heat to the windings?
or is that just for brushed motors? dissipating 887w is probly not a very healthy option for this motor, but i spose it could take it for about half a minute.

by the way, its a good peak torque figure, beats most 250cc 4 strokes..
 
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