RE: [CAD_CAM_EDM_DRO] Re: Yet another NEMA 42 roadblock

Tim (and the rest of you):

Yea, I'm an electrical engineer. (Gee, it shows?). Give me a building to
design or a complex computer network, transformers, computers UPS's,
whatever and it's cake. Its been more than 30 years since I played with
servos in school (lot of grey cells lost since then), and I never touched a
stepper till now. I'm not afraid to go where I haven't before (building a
CNC Bridgeport as my first project with a knowledge base of zero as an
example), but I've created too many piles of junk in my life that started
out as gold not to at least try to cover all the potential problems before I
throw the switch.

Thanks again for all the help,
Jeff

Jeffrey Goldberg, President

Washington Computer Services
140 58th Street - Suite 8F
Brooklyn, N.Y. 11220

Tel: (718) 491-6100
Fax: (718) 765-1973
email: jeff@...

If you can describe what you want your network to do,
We can design it, install it, and get it working
Always with an eye to exceeding your expectations


-----Original Message-----
From: Tim Goldstein [mailto:timg@...]
Sent: Thursday, February 20, 2003 1:40 AM
To: CAD_CAM_EDM_DRO@yahoogroups.com
Subject: RE: [CAD_CAM_EDM_DRO] Re: Yet another NEMA 42 roadblock


You checked it with the ohm meter to determine which terminals are the end
of coils. That is your sanity check.

Now just connect a pair of coils to the drive, connect the drive to 24 vdc
and set the amperage to .5 amp or so and just figure it out. The CMD drive
has a lot of self protection and at 24 V .5 amp you are not going to damage
a NEMA 42 motor, but you sure can verify that it is working properly. You
are not going to be learning anything until you put some action into trying
the motors.

I can't resist asking, are you an engineer by any chance??

Tim
[Denver, CO]
Sherline products at Deep Discount
Mach1 & DeskCNC with credit card ordering www.KTMarketing.com/Sherline Now
selling Visual Mill

> -----Original Message-----
>
>
>
> I looked at the archives and realized that I may have a Sigma
> (rather than a Superior Electric) NEMA 42 stepper. (Someone
> told me that if the screws are in two lines, like mine,
> rather than in a circle then its likely to be a Sigma).
> Sigma's were apparently used by Bridgeport as well during the
> time my machine was made. As my motors are unmarked, this
> could account for the difference in terminal nomenclature.
> I've been unsucessful in finding any information about their
> motors on the web. Do you know where I can get this type of
> data? (I'm reasonably comfortable that I'm at lest in the
> ballpark on my voltage and current assumptions (2.1 volts and
> 8.5-9 amps based on the motor's resistance of about .28 ohms
> and a number of spec sheets from various manufacturers), but
> I'd like to do a sanity check on the windings before I
> destroy a motor because of my own stupidity.
>
> Any help would be appreciated.
>
> Regards,
> Jeff