[n2xd]

Can any one tell me what major brand these servos and drivers are copies of?

https://www.ebay.co.uk/itm/750W-NEMA...oAAOSwux5YKVix


Thanks.


John

[skrubol]

They look pretty generic. Don't see any defining features of any particular brand.

[j3dprints]

I bought a few 6 months ago from aliexpress (check them, they may be cheaper for you - just search for 750w servo) but I havent gotten around to installing them yet. The high voltage aspect is becoming a major barrier for me! The manual says they require contactors with surge protection, I don't suppose you would be familiar with how to wire such a setup for single phase? I've googled to no avail, might have to start a thread.

Might be worth getting lower voltage servos, I kind of wish I had now, or something with a better manual. I heard another guy who got the servos I did (https://tinyurl.com/yc7oq3y2 - similar to these) said he oversized them cause the manual would be too hard to decipher to work out how to tune them. DMM were the next step up for me or some Delta clone. DMM were twice the price but name brand + you get all the electrics. To stay on the cheap side I probably should have gone with genuine Leadshine closed loop steppers - easy as heck to set up.

The ones I got are KRS servos, you can ask the supplier for a manual. I found what looks like a good translation online by searching "KRS servo manual" at this link - https://www.machsupport.com/forum/in...0;attach=44811
Should ask you to save as dkNew or something dot pdf.

[mactec54]

Can any one tell me what major brand these servos and drivers are copies of?

https://www.ebay.co.uk/itm/750W-NEMA...oAAOSwux5YKVix


Thanks.


John

The motors for these have been ok the servo drives have had problems and very had to setup /tune

DMM is your best choice DMM | Technology Solutions | AC SERVO DRIVE | AC SERVO MOTOR | ROTARY ENCODER

[asuratman]

I found servo drive and motor 750 watt with 2.4 Nm torque as per ebay and for my cnc, I use 4 stepper drive and motor 3Nm (425 oz in) need only 48 VDC 600 watt power supply. I don't understand what are the differents torque/wattage in servo and stepper ?

[skrubol]

Torque ratings on servos and steppers are totally different. Rated torque on a servo is the continuous torque it can provide, usually all the way up to its rated speed. Servos typically have a peak torque rating of 2-3x the continuous rating, which is what they can handle for brief periods of time (somewhere between 1-10 seconds usually.) Peak torque may only be available at low speeds (it may drop off as you approach the rated speed.) If you exceed the maximum torque, the drive will fault, which if it's wired up correctly to your controller should halt the program, hopefully avoiding any damage.
On a stepper, the torque number is generally the holding (0 RPM) torque. Torque falls off quickly with speed, and most steppers top off around 1500 RPM with almost no torque. Usable torque is typically only below 500-1000RPM depending upon the stepper. At that point usually the torque has dropped to around 1/4 the holding torque. Steppers have no concept of peak vs continuous torque. If you exceed the torque of a stepper, it will skip a step and usually stall, but generally the drive will not know it has stalled so the program will continue on, likely ruining your part and possibly breaking your cutter and damaging your fixturing.