Re: [CAD_CAM_EDM_DRO] Re: Selecting a DC motor for Servo Motor Use.

On April 5, 2005 11:00 pm, lcdpublishing wrote:

> How can one check for this timing effect you are talking about. Is
> there are way to measure it either statically or electrically?

You might be able to see it, that's how it used to be done in the old days on
big machines. An operator would visually monitor the brush sparking and
shift the brush nuetral plane manually while the machine was running for
minimum sparking, before they made use of commutating poles. Check out this
link:
http://zone.ni.com/devzone/conceptd.nsf/webmain/7A37EE2E2E1628528625690000653B76#3
As John Heble suggests you'll probably want to get the brushes on the magnetic
nuetral plane with no shaft load. If you can see it, fix the the brush axis
in one location for the least amount of sparking in both directions. That
way the motor will perform optimally in both directions. Armature reaction
increases with increased load but is usually not a great concern at partial
loads. You might be able to adjust by using a scope on small series
resistance in one leg of the motor circuit.
cheers,
DC