## BG Micro stepper controller and floppy drive steppers...

### BG Micro stepper controller and floppy drive steppers...

I've got one of the stepper motor controllers from BG Micro.  It's
actually a Bodine THD1801B.  There's instructions included for setting
it up to run by itself (with switches) and with TTL input.  I'm
planning to do it in that order.  Has anybody ever used one of these

ALSO, it gives the equations for calculating the values and wattages
for the series and suppresion resistors.  These require you to know Im
(rated motor current per phase) and Rm (motor resistance per phase).
I can get the Rm with my DMM but does anybody know the rated current
per phase for a standard floppy drive stepper?  Is there a way to
calculate it?  Are they all pretty much the same?  Also.  I need to
know Vpl (power supply voltage value while under twice Im load).  How
do I figure that one out?

Thanks for any and all help.

Mechanical Engineering Student
Southern College of Technology            "It is what you make it."
http://www.mindspring.com/~wdnick/resume.html

Hello all!
This is my first post to this group.

I want to build a part indexer for a laser.
I'm going to burn the continents of Earth into orbs made of
hard wood covered with polymer clay.

http://www.akrobiz.net/~james/poly_earth/index.html

This prototype was made by first covering a hard wood
sphere with blue and silver marbled polymer,
cooking it, cutting the continents with a Dremel,
back-filling with land colors,
cooking again and polishing and finishing it.

I want to spin the orb on its axis with one stepper
and rotate that whole assembly perpendicular to the first axis.

The Earth axis stepper should rotate many times around
but the axis that causes the Earth to turn North pole over South pole
only needs to turn 180 degrees.

I want to use a fixed point laser and move the part.
The laser will point right into the center of the orb.
This way, it doesn't really matter how big the orb is or if it is
a perfect sphere; which they are not!

I have a few Teac 5.25" floppy drives; model FD-55GFR.
I understand that the controller cards in these things can be
directly interfaced with a parallel port on a computer
and the motors can be driven simply by banging bytes into the