Re: Re: Re: Re: Ball/Lead Screw mapping

Hi Raymond

I spent a bit of time today looking for an illusive description that I
remember reading several years ago but I didn't find it. You might want
to think of the rest of this as my best guess.

One of these files (x.cmp) looks like this

0.000000 0.000000 0.000000
0.100000 0.100000 0.100000
0.200000 0.200000 0.200000
0.300000 0.300000 0.300000
0.400000 0.400000 0.400000
0.500000 0.500000 0.500000
0.600000 0.600000 0.600000
0.700000 0.700000 0.700000
0.800000 0.800000 0.800000
0.900000 0.900000 0.900000
1.000000 1.000000 1.000000

What I remember is that the first column is the expected position given a
perfect actuator. The second column is the actual position that should
be used when the perfect position is commanded and you approach from a
lower numbered position. The third does the same except it is used when
approaching the perfect number from above.

I believe that you can use as course or fine a resolution as you like.
The only limitations to this is that the variation will be added in as a
linear offset between points.

This design not only allows for stretch in a screw at different places
along it but allows for additional slop like you might get from a
bridgeport acme screw when you mostly have used the center of the bed.

Hope this helps

Ray



On Saturday 22 November 2003 2:34 pm, CAD_CAM_EDM_DRO@yahoogroups.com
wrote:

> Message: 14
> Date: Sat, 22 Nov 2003 10:16:21 -0800
> From: Raymond Gage <gagefam@...>
> Subject: Re: Re: Re: Ball/Lead Screw mapping
>
> Ray,
> Do you know what the formating is for these files?
> Regards,
> Raymond
>
> Ray Henry wrote:
> >When the emc starts up it looks for files named x.cmp, y.cmp, .... If
> >they exist in the directory that emc is running from it will use them
> > for machine error comp. It can also comp temperature if you wish and
> > have the input device.
> >
> >Ray