inertia matching

Good Sven!

This is a subject with sometimes bewildering differences of opinion among
motor, controller, and other suppliers.

Let's see if we can come off with a basic understanding of the phenomenon.
I think it would be of good general interest.

Tonight. Right now I have the curious new problem of making stuff with
cnc machines rather than making the machines! Off to the shop.


Leslie Watts
L M Watts Furniture
Tiger, Georgia USA
http://www.rabun.net/~leswatts/wattsfurniturewp.html
engineering page:
http://www.rabun.net/~leswatts/shop.html

----- Original Message -----
From: "Sven Peter" <peteryco@...>
To: <CAD_CAM_EDM_DRO@yahoogroups.com>
Sent: Wednesday, June 19, 2002 7:26 AM
Subject: Re: [CAD_CAM_EDM_DRO] handle inertia was (Re: Mariss' power supply
circuit)


> Hello Less,
> that is an excelent point that imo should be handled as a own thread
> I have to hande some smaller cases where you see an negative efect out
> of this problem.
> example a 2 meter knife grinder where the carriage bumps fast slow fast
> slow over the hole lenght. Result waves in the knife edges.
>
> Right now I go to adjust a pump regulatio control with so much
> fluctuation that the pump cavitates although it is driven by an
> inverter.
> Regards
> Sven Peter
>
> Les Watts wrote:
> >
> > > hay how about a livley discussion on rotor/system inertial mismatches
> > > tomorrow night!!
> > >
> > > John H. Berg
> >
> > I would be happy to discuss inertial matches. I have been modeling some
> > machine components as transmission lines. With some components (longer
> > ballscrews) I have tried terminating them in their characteristic
mechanical
> > impedance with good results.
> >
> > I am also playing around with second order mechanical resonant absorbers
> > particularly on gantries.
> >
> > And as I have mentioned before EMC has the basic bandwidth capability
> > to do some anti-vibration functions.
> >
> > Although my latest system is a close inertia match on x I do not think
it is
> > of overiding importance. I think one can get higher accelerations with
> > the same (complex) power by driving with a lower mechanical impedance
> > even though system energy transfer is not optimum. Theoretically I^2R in
> > the motor armature is minimised at 1:1 (for a given output) but that
> > often is not a particularly critical design requirement. I have a 2:1
and
> > 3:1
> > inertia mismatch on y and z on the latest machine.
> >
> > Look forward to discussing!
> >
> > Les
> >
> > Leslie Watts
> > L M Watts Furniture
> > Tiger, Georgia USA
> > http://www.rabun.net/~leswatts/wattsfurniturewp.html
> > engineering page:
> > http://www.rabun.net/~leswatts/shop.html
> >
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> Addresses:
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>
> OFF Topic POSTS: General Machining
> If you wish to post on unlimited OT subjects goto:
aol://5863:126/rec.crafts.metalworking or go thru Google.com to reach it if
you have trouble.
> http://www.metalworking.com/news_servers.html
>
> http://groups.yahoo.com/group/jobshophomeshop I consider this as a
sister site to the CCED group, as many of the same members are there, for OT
subjects, that are not allowed on the CCED list.
>
>
>
> Post messages: CAD_CAM_EDM_DRO@yahoogroups.com
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> bill,
> List Mom
> List Owner
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