Re: [CAD_CAM_EDM_DRO] newto cnc - - - - - - - advice on servo motors please.

mcculley_neil wrote:

>Hi,
> I have the chance to obtain some dc servo motors. I have the
>following specs from the side:-
>
>motor/encoder servo dc
>65 volts max, 10A max (motor)
>5volts.200pulse/revolution(encoder)
>3000 rpm
>
>I am trying to find out
>
>a) are these suitable for cnc milling?
>

Probably. 650 W is not bad, almost one HP, peak. You don't give a
continuous
rating, however. You also don't specify the size milling machine, whether
it has ballscrews or Acme, and what kind of performance you need on what
type of work. If you are planning to hog out large cavities on a Bridgeport
Series-II machine, they would be too small. If you are planning on cutting
balsa wood on a Sherline, they are too big.

>b) what size of mill would they suit best?
>

Maybe a Taig, or minimill, probably up to a series-I Bridgeport with
ball screws.
You should plan on a belt reduction of at least 2:1, and maybe more like
4:1.
You certainly don't need to spin a Bridgeport's cranks at 3000 RPM.

>c) what would be a fair price for these (brand new)
>
>

Ugh, that's real hard to say. Are they high-end, name brand machine
tool motors, or are they lower-grade, commercial motors? I'm
assuming in all this that these are BRUSH motors. If they are
brushless motors, you'd better look into the drives required before
buying them.

Jon