[BPE3976]

Hi,
why do you think it essential that you have encoder feedback for your spindle?

Is it position capable or something?

I use 750W Delta B2 servos, it was the first time I'd used AC servos so I had a current monitor on each of them .Waste of time. 99.99% of the time they draw next to no current at all and only
for a tenth of a second or so do they draw any real current. My estimate is that the closed loop steppers (being variable reluctance) will draw more than AC servos would.
I personally would discount the 'current draw' argument if that is all that is stopping you from getting servos.

Personal experience is that servos EAT steppers, any stepper for breakfast!

Craig

Hi Craig,

The spindle motor is a fanuc servo with a pulse generator encoder. If I wanted to do position monitoring for an atcdown the track, its helpful. Also, being able to monitor real time rpm and set torque requirements through the vfd will be advantageous.

I also agree, servos should outperform closed loop steppers, no argumentat all. That being said, i've not played with servos alot (a little in my job, but that's about it) I'm only going off the amperage draw charts that the manufacturers supply. I agree that the manufacturer usually will put worst case full load capacity on any chart they send out, so I was working with that.

The closed loop steppers I currently use, are 12nm nema 34's, they draw about 2 amps each on full load on single phase 240v. I'm curious as to what anyone has measured on a 1kw servo on a machine of similar size.

Thankyou,

Shane Barnett