Re: newto cnc - - - - - - - advice on servo motors please.

--- In CAD_CAM_EDM_DRO@yahoogroups.com, Jon Elson <elson@p...> wrote:

>
>
> 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

Hi Jon,

sorry don't know the continuous rating. They are Yaskawa motors.
They would be used on large benchtop to small knee mill (still
deciding on which to purchase). Will be used mainly for milling
copper and aluminium. These 3 motors are currently on Ebay
(http://cgi.ebay.co.uk/ws/eBayISAPI.dll?
ViewItem&item=3825869369&ssPageName=STRK:MEWA:IT)for $65 dollars
each. I think at that price they will be brushed.

Neil