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

HumboldtRc said:
What does "kt" stand for? torque?
Click to expand...

It the motor's torque constant. It is in units of Newton meters divided by amps.

If you were to multiply the motor current by this constant, you'd get the torque.
 
about half way down this page I show the physics envolved to convert the kv (Voltage constant) to kt (Torque constant)
http://endless-sphere.com/forums/viewtopic.php?f=10&t=18609&start=15

-ryan
 
Hey all. We just got this thing in today and spun it up.

I must say, it's the coolest looking motor that Hobbyking sells. It's all blacked out and anodized - very much a departure from the chrome cases of the others.

But, in classic HK fashion, it's a little lacking in legitimacy. The rotor case is aluminum! I can't see any steel backing or magnet ring. The magnets appear to be glued right to the Al case, and as a result, the thing can pick up a set of 10 inch lineman's pliers and hang it in midair. Alot of flux is just going to waste there.

Though constructionwise, it's pretty solid. The can bearing is a 6814 type, 70mm bore, and the shaft bearings are 12mm. I can confirm the ridiculous no-load amps - measured at 16-17 amps at 12S LiFe. 24 tooth stator, 28 magnet poles.

I think that EVwise it does not offer significant advantages over the 80/100 because of the Al case. It's a very fast motor for sure.

However, if someone were to make an identically dimensioned STEEL can, it would be a torque monster.
 
teamtestbot said:
Hey all. We just got this thing in today and spun it up.

I must say, it's the coolest looking motor that Hobbyking sells. It's all blacked out and anodized - very much a departure from the chrome cases of the others.

But, in classic HK fashion, it's a little lacking in legitimacy. The rotor case is aluminum! I can't see any steel backing or magnet ring. The magnets appear to be glued right to the Al case, and as a result, the thing can pick up a set of 10 inch lineman's pliers and hang it in midair. Alot of flux is just going to waste there.

Though constructionwise, it's pretty solid. The can bearing is a 6814 type, 70mm bore, and the shaft bearings are 12mm. I can confirm the ridiculous no-load amps - measured at 16-17 amps at 12S LiFe. 24 tooth stator, 28 magnet poles.

I think that EVwise it does not offer significant advantages over the 80/100 because of the Al case. It's a very fast motor for sure.

However, if someone were to make an identically dimensioned STEEL can, it would be a torque monster.
Click to expand...

How would steel affect flux wastage and efficiency? I guess I understand the legitimacy of steel if you're building combat bots. :mrgreen:
 
teamtestbot said:
Hey all. We just got this thing in today and spun it up.

I must say, it's the coolest looking motor that Hobbyking sells. It's all blacked out and anodized - very much a departure from the chrome cases of the others.

But, in classic HK fashion, it's a little lacking in legitimacy. The rotor case is aluminum! I can't see any steel backing or magnet ring. The magnets appear to be glued right to the Al case, and as a result, the thing can pick up a set of 10 inch lineman's pliers and hang it in midair. Alot of flux is just going to waste there.

Though constructionwise, it's pretty solid. The can bearing is a 6814 type, 70mm bore, and the shaft bearings are 12mm. I can confirm the ridiculous no-load amps - measured at 16-17 amps at 12S LiFe. 24 tooth stator, 28 magnet poles.

I think that EVwise it does not offer significant advantages over the 80/100 because of the Al case. It's a very fast motor for sure.

However, if someone were to make an identically dimensioned STEEL can, it would be a torque monster.
Click to expand...


So the shaft is 12mm? not 10mm, like the spec's say? Also, what esc are you testing it with?
 
teamtestbot said:
Hey all. We just got this thing in today and spun it up.

I must say, it's the coolest looking motor that Hobbyking sells. It's all blacked out and anodized - very much a departure from the chrome cases of the others.

But, in classic HK fashion, it's a little lacking in legitimacy. The rotor case is aluminum! I can't see any steel backing or magnet ring. The magnets appear to be glued right to the Al case, and as a result, the thing can pick up a set of 10 inch lineman's pliers and hang it in midair. Alot of flux is just going to waste there.

Though constructionwise, it's pretty solid. The can bearing is a 6814 type, 70mm bore, and the shaft bearings are 12mm. I can confirm the ridiculous no-load amps - measured at 16-17 amps at 12S LiFe. 24 tooth stator, 28 magnet poles.

I think that EVwise it does not offer significant advantages over the 80/100 because of the Al case. It's a very fast motor for sure.

However, if someone were to make an identically dimensioned STEEL can, it would be a torque monster.
Click to expand...


I can't wait till mine gets here. :)

Looks like I will be making a steel rotor section for mine then... I hate the idea of the massive eddy current losses the motor would get spinning near anything conductive with no steel backing. It should also lower the KV by a pretty large amount to do a steel rotor ring (higher flux density between the teeth and magnets).

That no load current is definately a problem as well... Any chance you wana try removing the skirt bearing and re-testing the no load current? :)
 
swbluto said:
How would steel affect flux wastage and efficiency? I guess I understand the legitimacy of steel if you're building combat bots. :mrgreen:
Click to expand...

The lack of steel does! Half the flux in that motor is leaving and never returning.

I suppose one reason they did it that way was to increase the Kv to something an R/C modeler would find useful. We EV hackers won't mind Kvs in the 30s and 50s, but a plane spinning a prop would find that less desirable, I guess. If you fully replaced the aluminum rotor with a steel one of equal thickness, you could drop the Kv to the high 2 digits range easily. Just adding a steel ring around the outside could probably help you 10-20%.
 
where do you guys get info for this motor ? Its steel and very good magnetism on steel, thats why you can feel magnetism at the outer can , and no problem with putting external hal sensors to sense the magnets.
I got to say : i we bought and payed motor more than its on hobby site direct. So its a good deal and i really like the motor
 
No Model KV Voltage Range(V) No load Current(A/V) Max Surge Current(A) Max Surge Watts D(mm) L(mm) Weight(g)
MOTOR 1 40 30-70 18/30 200 15000 120 80 2650

This is CORRECT factory data FOR THE 140KV MOTOR that i recived from factory 4 months ago
 
markobetti said:
Its steel and very good magnetism on steel, thats why you can feel magnetism at the outer can , and no problem with putting external hal sensors to sense the magnets.
Click to expand...
You'd feel it a lot more, if it wasn't steel :wink:
 
Pity they don't give the resistance...

Kt is 0.0682 Nm/A .. So, torque at the max. surge current (200 amps) is 13.6Nm.

I don't understand how they get the 15,000 Watts figure??? :)
 
I dont know... only thing one can do is "test" . Data that i recived and on Turnigy is compleatlly different... Anyways you will be able to follow my build with this motor and i hope in a month i will drive so we ll see if its any good..
 
It says 15,000 as the "max surge watts"
This can mean just about anything. lol
 
As i said ..its steel :

The material of steel can is 10# improved carbon structural steel, Chinese standard GB/T 699-1988.
 
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