Re: [CAD_CAM_EDM_DRO] Please help me identify these stepper motors

washcomp wrote:

>I'm new to this and unfortunately, I'm trying to retrofit a
>Bridgeport milling machine by changing the existing NC controller
>with modern drives without any documentation or specifications.
>
>The BP has NEMA 42 stepper motors on XY and Z axis. The motors weigh
>a little over 19 pounds each. The eight connections are laid out in
>two rows in the back. The motors measure 6 3/8" on the cylindrical
>part and 6 7/8 including the square mounting flange. The existing
>power supply runs about 62 volts DC. When I test the resistance of
>one of the windings, it's so small, I can't get a reliable reading.
>(I guess in a pinch, I can connect all the coils in series and
>measure the total and divide by 4).
>
>Any clues if this is one or two rotor (I read here that it's not a
>good thing to disassemble stepper motors and physically check)? Any
>idea what a reasonable current setting for the drives to try out the
>setup?
>
>

1 or 2 rotor? Do you mean 1 or 2 stack? What is the difference. These
are the motors
the manufacturer designed into the machine, and unless they are damaged,
you might
as well continue using them. 62 V is acceptable for some of the stepper
drivers, such as
Gecko. You can run each phase with half winding at about 8 A, or
parallel the 2 windings
per phase at about 4 A. The BOSS machines genearally had a 3-phase
transformer for
the stepper motors' power supply.

Jon