Re: Pleaes help !!! Stepper Motor Question.

--- In CAD_CAM_EDM_DRO@yahoogroups.com, "shawnusa2002"
<shawnusa@e...> wrote:

> Thanks for the reply. I confirmed that the earth shield wire was
> just mearly grounded to the motor case as you guessed. So I infact
> have a 4 wire Stepper. What does this mean? I was all planned out

to

> use a 8 wire stepper with a Compumotor 8 wire drivers I picked up.
> Now, I have no clue what to do from here.
>
> 1. Is this 4 wire stepper Uni or Bi Polar?
> 2. Can I use this with the 210 or 201 Geckos?
> 3. Which Gecko model if any should I choose (201 or 210)?
> 4. Am I better off getting diffrent motors?
>
> I plan to upgrade a HF Mini Mill with these. And to think. I still
> have to choose screws types for the z-axis and pick a nice software
> package. Man what one goes through to get to the art of CNC.
>
> Anyway, I'm kinda stumped now on what I should do next. Any help is
> greatly appricated.

What you have is a motor with two windings and no center taps. A 6
wire motor is a two winding motor with centertaps. Most motor drive
units have four output pins : A+ A- B+ B-. On six wire motors you use
either half winding (on end and a center tap) or full winding (both
ends ignore the CT) A four wire motor is the easiest to hook up
since there are no decisions to make. If the motor driver has more
than 4 outputs then it's either a unipolar driver or something
different than a general stepper driver. Your motors will work
bipolar or unipolar but bipolar is the recommended approach.

Your decision to buy a Gecko should be made once you determine your
current drivers are not capable of running the motors you bought (not
likely). The difference between a 201 and 210 is that the 210 has an
intergal step multiplier. If through the combination of belt
gearing, leadscrew pitch and max speed you want in IPM plus the 10:1
microstepping Gecko (both units), exceeds the ablity of your
controller software's PPS (pulse per second) output then the 210 can
put in the extra steps for you. This lowers your effective
resolution, but if you end up with a design that takes 20,000 pulses
to move one inch, then that would drop by the value of multiplication
you choose in the 210. A lot of the PC based controller software
maxes out at 15 to 25 thousand pulses per second. If you need some
help with the calculations just post what leadscrew pitch and belt
ration (if any) you plan on using and one of the members can give you
your required pulse rate to go a certain max speed. You will have to
play around with several "what if" designs where you trade speed for
torque using different pitch leadscews and gearing. There is a
finite RPM you can spin the steppers at and maintain enough torque to
drive the mill. Other list members can give you real world examples
that may be able to guide you in the component selection process.

>
> Thanks,
>
> Shawn
>
>
> > Check the wires to the case with a meter. My guess is that the
> earth is
> > just a ground wire to the case and does not connect to the phase
> wires.
> > I have had some motors like that and just ignores the shield.
> >
> > Tim
> > [Denver, CO]
> > Sherline products at Deep Discount
> > Mach1 & DeskCNC with credit card ordering
> > www.KTMarketing.com/Sherline
> > Now selling Visual Mill 4.0
> >
> >
> > > -----Original Message-----
> > > I have 3 Compumotor M83-135's. I just recieved them in the mail
> > > today and what I thought was a eight wire stepper has turned
> into a
> > > 5 wire setup. I do not know if this is a Unipolar or Bi-Polar
> > > stepper. The wire setup is as follows
> > >
> > > Phase 1 + Wht
> > > Phase 1 - GRN
> > > Phase 2 + BLK
> > > Phase 2 - RED
> > > Bar wire - Earth shield