RE: [CAD_CAM_EDM_DRO] Re: Re: Re: breakout boards plus - hard choice

Yes Steve, I didn't bother to relate the angle with steps quoted which with
a little inertia, and probably delay in the measurement will be how they are
getting away with this angular error and no lost pulses.



Dr. Mark Vaughan Ph'D. B.Eng. M0VAU

Managing Director

Vaughan Industries Ltd, reg in UK no 2561068

Water Care Technology Ltd, reg in UK no 4129351

Addr Unit3, Sydney House, Blackwater, Truro, Cornwall, TR4 8HH, UK.
Phone/Fax 44 1872 561288

RSGB DRM111(Cornwall)

_____

From: CAD_CAM_EDM_DRO@yahoogroups.com
[mailto:CAD_CAM_EDM_DRO@yahoogroups.com] On Behalf Of Steve Stallings
Sent: 20 July 2007 02:04
To: CAD_CAM_EDM_DRO@...
Subject: [CAD_CAM_EDM_DRO] Re: Re: Re: breakout boards plus - hard choice



A typical stepper is 200 step/revolution or 50 poles. This type
of motor can lag 3.6 degrees before losing its way. Add
inertial to the mix and lagging 3.6 degrees without losing
a step is quite believeable. It should be noted that this is
actually 1/2 of a pole of lag, not 2 poles.

Steve Stallings
www.pmdx.com

>
> Hi Mark,
>
> I'm surprised as well. I expect that the momentum of the machine keeps it
> travelling, but it doesn't explain how it gains the step back.
>
> Cheers,
>
> Peter.
>
>
>
> Mark Vaughan wrote:
> > Hi Ron
> >
> >
>
> >
> > I thought though that 2 poles lag was the point at which you normally
> > irrecoverably loose a step, and normally you limit acceleration to stop
> > loosing pulses with a basic stepper drive which does not have an error
> > counter and cannot move onto the next step unless the previous one is
> > committed and almost completed by the motor.
>

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