Re: Help and advice needed please.

In an eight-lead unipolar stepper, the two coils on each of the two
stator poles are separately wound. If you're lucky, the mfr may have
grouped the stators apart from one another with some sleeving. Since
you have the color codes, it should be a lot easier. At the least, a
meter will tell you which pairs of wires go to a given coil. (A
common color-coding is putting a stripe of the matching color on the
other end of each coil.) Even with separating the coils for the two
phases, you still have to determine which direction to parallel each
pair of coils to get the field directions so they're not fighting each
other (like two equal transformer windings). It's generally quickest
with an *unknown* motor just to take a few minutes and try different
combinations until it steps with decent torque. Write it down so you
don't get confused as you go. If you can, set your step rate low
enough so you can see each step, say a few pulses per second. It
won't hurt the motors to simply be out-of-phase with themselves,
although it sounds as though pieces of bearings should be flying out.

You are correct that you will be soldering pairs of wires together, as
you want two coils in parallel. You just have to figure out which
direction. I don't know what you're docs say, but if there's a
schematic showing a dot next to a lead with a color name, you're home
free since that is your coil polarity marker. You'd want to connect
dot-to-dot in that case.

Good luck!

Don

--- In CAD_CAM_EDM_DRO@yahoogroups.com, "snokket" <graham@a...> wrote:
<snip>
> The stepper motors have eight wires. I have been advised to wire
> them up in the parallel mode and I have the colour codes but.. the
> molex pin has only four connections marked for the wires from the
> motor.
> Do I solder the two wires together for one connection
> ( EG, white-orange wire and black wire to give the A+ connection )
> then solder the joined wires into the female pin ?