searching brushless motor with sensors, 12V, 500-700Watt

Look at stepper motors., they have a high torque rate of holding how ever, they work in degree's/ indexes per turn. the more you get the more expensive and at 700 Watts, that sounds very expensive.

On the second note how ever, they require no feed back.

the 14xx6 motors have a stall current of 54 amps at 12 v -- just over 600 watts -- and come with HP encoders for servo applications

Try Alxion, or Danaher. What you don't say, is how fast you want to go, or how 'high', 'high torque' is?. The problem will be maintaining torque at higher rotational speeds with such a low supply voltage (this is why cars that use high power motors for things like steering, and traction applications, all use higher voltage supplies). It will almost certainly have to be 'custom', because of the low supply voltage (Bosch do make some units like this for

Best Wishes

On the third note:

- they're far bulkier for the torque than a brushless

- they consume far more power for the torque than a brushless

- if the load should exceed the torque capability of the motor the motor's average torque will go to zero, leading to a failure mode that is, at best, unrecoverable until things stop.

Stepper motors are good for simple applications when you can afford to significantly over specify. Other than that they're way more trouble than they're worth.

One low cost solution is an automotive inverter and a 1 HP induction motor. You probably need a 1500 W inverter to handle starting current surge. PSC or capacitor start motors have high starting torque. If you will be running at very low speeds, it may be better to use a three phase motor and a VF drive. You can directly convert the 12 VDC to 180 VDC internal DC bus for the drive.

I have also rewound small single phase motors to be three phase, and with heavy windings to run directly from 12 VDC. I still need to build a good low voltage VF drive, however.

Paul

Have you done a web search? I'd check Maxon, Escap (Faulhauber, if I have the spelling right) and Aveox. Aveox is a US company, but Maxon and Escap are both Swiss, so it may be easier for you to talk to the factory.