Re: [CAD_CAM_EDM_DRO] Ametek DC motor info?

Shawncd wrote:

>Does anyone out there no where I can view information for the Ametek DC
>motors? I have a few that I can buy for a very reasonible price, with
>encoders already mounted. But I can't seem to find any specs for the model I
>want.
>If anyone has used these in a CNC application I would like to know how they
>worked out for you. Are they good canidates for CNC projects? The two I'm
>looking at will be used on a CNC plasma table.
>
>The specific model is
>116870-01
>40vdc
>Thanks in advance!!!
>
>

Yup, there are thousands of these motors out there. I think they were
used in the CDC "Keystone" tape drives. They work pretty well for
mid-sized mill and similar CNC applications. They have too much
resistance for heavier machines, such as the Series I Bridgeport.
You can still use them, but unless you use a 72 V power supply, you
can't get anywhere near peak current through them. If you start
with the 4 Ohm or so motor resistance and then add a few Ohms
for the driver, it takes up to 70 V to get 10 A flowing, and that is
with the motor standing still. If you add the back EMF, it gets
even worse.

I have a client in town who has a machine like the Grizzley 1126
(the geared-head mill) and it works pretty well using these motors.
He only has a 36 V power supply now, and that limits the speed and
torque a bit. But, it DOES work pretty well.

For a plasma table, you'd want a pretty coarse leadscrew thread,
or a larger pulley for belt drive. I think the motors are rated for
900 RPM at 40 V. You can get more speed at higher voltage without
harming the motor.

Jon