Question For Cobra Owners

[VanDutch]

Whilst we are on the subject of servos, here is a torque curve of a servo motor. Servos actually lose torque at higher RPM. Totally opposite to an induction motor.

03_speed_torque.jpg

In reality a True servo/stepper motor has the most torque at 0 RPM. The type of servo motor fitted is most probably not a true servo because otherwise we would be unable to handwheel when the unit is switched on..

Anyone actually know more about the motors fitted?..

I have received several PM's from owners with similar issues. I do want to make it clear this discussion is not about the machines but rather the motors. Issue seems to be the motors do not have sufficient toque to punch through thick leather at very slow speeds without additional speed reduction.

Edited May 4, 2014 by VanDutch

[Trox]

Hi VanDutch,

I understand you have the King Cobra machine with the EPS motor (position motor). I do not have the same setup as you. I use a expensive Efka servo system on my 441 machine that are strong enough without a speed reducer. I do have a regular Cobra servo/speed reducer on one of my other machines (same motor without EPS) These motors are among the most powerful economical servo motors on the marked today. Although they have had some faults on the speed control before (that has been fixed now) they have always had enough power. Very strong compared to others in the same class (price range). Its not fair to compare them to `high end motor systems as Efkas and Ho Sing that cost 1k $. If its a loose part on the machine somewhere in the needle feed a position system will stop, it reports the wrong position and the motor will stop. Or turn an extra rotation, thats the way these systems works. What ever the fault is you can rest assure you are in the best hands, Steve will make it right. And if it is a motor problem, I still think its related to the position system. The EPS motor is the same as the regular servo motor with a built on needle position system, same spec`s, power and torque. Together with a speed reducer it should have no problem sewing that on slow speed.

Good luck.

Tor