Maxium torque turnigy 80-100 130kv?

[DeathBlade]

I'm trying to figure out if I have enough gearbox for my latest bad idea

I have two 80-100's 130kv that I'm going to press the motor shafts out of and then press one long shaft between both motors. Clocking them so the magnets and coils are aligned so that I would have essentially one big motor I guess you could call it a 80-200 or maybe 80-100².

Now I'm planning on adding hall sensors, and the usual, but I'm running up against a wall when it comes to the torque output. I know that its a constant of the phase current, but since I haven't spec'ed a controller my answers is ??? I do have one of Lyen's 12fet controllers laying around to do testing. My pack voltage is 48v 12s4p 5ah lipo plan on taking it to 12s8p later.

So knowing that what do you guys think would be a typical phase amps?

Now as for the gearbox I have a bayside RA90 right angle box on hand with a 10:1 which should be able to take 800 in-lb or 90nm of output torque.
And I have been looking at a RA60 in 10:1 and 8:1 which can take 300in-lbs or 34nm of output torque, since the RA90 is heavy nearly 10lbs and very large, alot larger than I estimated. The ra60 would be alot more manageable size wise.

Now its just to figure out what my motor torque would be to do the math to see which gearbox would survive.

 

[gwhy!1]

I can treally say for the 80100 ( i use the 8085's ) but im guessing there will be very little different in torque, and I run 220A phase on a modded 12fet controller per motor.

 

[DeathBlade]

So if this post is correct, and I run lets say your 220amps at .073Nm/Amp I have 16Nm of torque at 10:1 that would be 160Nm both gearboxes would explode

Jermey Harris wrote:Luckily, there is a fixed relationship (for a PM motor) between the voltage constant, Kv, and the torque constant, Kt. If you know Kv you can work out Kt fairly easily. Here is the formula, for Kt in N-m per amp:

Kt (N-m/amp) = 9.5478 / Kv

so, if you have a PM motor with a Kv of 50, then it's Kt = 9.5478 / 50 = 0.191 N-m/amp



So for your 130Kv motor, your Kt = 0.073 N.m/Amp.

The question then is ... How many amps are you going to throw at it?

 

[gwhy!1]

or this way ,

Torque (Newton-meters) = Power (watts) divided by angular velocity (radians per second)
radians per second = 2 pi RPM/60

Torque (Newton-meters) = Power (watts) / (2 pi RPM/60)


I cant imaging any small light weight planet gearbox holding up to the power of 2x80100's running at full pelt. to be honest

The 220A is the highest I have ever pushed the phase current to on a 12fet but to play it save call it 180A max.

 

[crossbreak]

180A for a 12fet?? WTF i am conservative I would say that 10Nm is pushing it already, that is around 180amps for a 180kV motor like the 8085-8t

 

[DeathBlade]

I was only going to use the 12fet for bench testing, I'm not that crazy, ok maybe I am