Re: [CAD_CAM_EDM_DRO] Stepper Motor and Cable Shielding. Any tips?

The basic rule is to try and keep power and signals separate, avoid any
ground loops, keep low power signals physically away from high power, and
screen/twist low power signals. Multiple 0v connections at different points
on the same signal pair must be avoided and declare one point for the 0v
connection point and connect the signal grounds at that point. Twisted
cables provide as much noise immunity as anything. If you use screened
cables then connect all the screens to a separate ground point before
linking to the main ground point. Don't connect the screens to this ground
point more than once.

This is how we used to deal with very high power drive systems and computer
signals so hope it works for you.

Regards Peter

----- Original Message -----
From: "kaynrc" <tom.kay@...>
To: <CAD_CAM_EDM_DRO@yahoogroups.com>
Sent: Monday, July 22, 2002 3:53 PM
Subject: [CAD_CAM_EDM_DRO] Stepper Motor and Cable Shielding. Any tips?


> In case you follow more groups than just this, I have also posted
> this in the Master5 group, with few replies thus far.
>
> I have a semi-sick stepper system, with Dan Mauch's 5 amp boards and
> Master5 as the software so far. (I'd like to stay with that one). The
> motors are new, 521 oz-inch also from Camtronics.
>
> I lost lots of steps on a bench test, whether I add resistance to the
> motor shafts or not (by hand). So I am losing steps somewhere, no
> matter how I adjust the feedrates or pulses per inch etc.
>
> I'm starting to suspect RFI or EMI is important and hurting my
> system, even if there are other causes on top of that.
>
> Can someone point out any shielding tips with respect to:
>
> 1. The parallel port cable (I have already bought some shielded-
> twisted paired wires, so I'll be making a cable, but what about
> grounding? Ground at one end only, and to the computer casing????)
>
> 2. The motors. Do they give off a hailstorm of RFI from the wires?
>
> 3. The wires from the breakout board to driver boards. Shield these??
>
> 4. Ground my case which holds the 3 drivers? Grounded also to the PC
> casing??
>
> 5. Anything I may have missed or gotten totally wrong, feel free to
> add in. I have, by the way, done a search on shielding in this and
> other groups, and gotten a good beginning picture. But I don't feel
> that I have the full picture yet. OK, I'm slow !
>
> Thanks for any feedback. Tom.
>
>
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