Re: Unknown servo motor specs

Hi,

Measure the 40VDC motor's armature resistance. Its peak power will be
W=V^2/4R. Measure the motor's no-load speed at 40VDC. The torque at
peak power will be in-oz=1351*W/RPM. Stall torque will be twice that.
Use 1/5 of stall torque as the maximum continuous torque rating.

Mariss

--- In CAD_CAM_EDM_DRO@y..., "David Micklethwaite"
<d.micklethwaite@o...> wrote:

> I have a couple of servo motors that I need to know more about

before I try

> to use them on a medium size mill I am trying to convert to CNC:
>
> 1. Label says "AMETEK, 40 V DC and some meaningless part numbers".

The case

> is 4" dia and 5" long with a 5/8" shaft at one end. The motor has

two

> brushes. How do I fugure out the maximum current for this motor? I

would

> have to drill the "back end" of the motor shaft to mount an

encoder - is

> this a reasonable thing to attempt?
>
> 2. Label says "Electro Craft Permanent Magnet Servo Motor". The

case is

> 3.25" dia and 5" long. The motor has a 1/2" shaft at one end and a

1/4"

> shaft at the other which has a small electro mechanical clutch or

brake on

> it. The motor has two brushes. There is no indication of voltage or

current

> on this motor so how do I figure out what it can take?
>
> Both motors have been scavenged from old equipment and so I have no

idea of

> their background. For once though, I can get more if I decide to

use them!

>
> Regards,
>
> Dave.
>
> David Micklethwaite
>
> Technical Sales Support Consultant, Cray Australia Pty Ltd
> Phone: +61 2 6295 4012 Fax: +61 2 6232 6218
> Suite 1, Level 2, 1-7 Franklin St, Manuka ACT, AUSTRALIA
> Postal: PO Box 3543, Manuka ACT 2603, AUSTRALIA