Re: [CAD_CAM_EDM_DRO] how straight is straight[rails]?

Hello Carl If I remember right a year ago somebody said that he built
his machine out of a granite plate. That is supposed to be within your
required flatness! I rescrape the rulers of my competitor and my own on
a brand new granite plate that is sitting there only for this purpose.
And I am sure I do not get stress into the material. On your length if
you want the bridge rigid it will become heavy!.
Good luck
Sven Peter

carlcnc wrote:

>
> I had a guy ask me if I can make a router within .001 straightness
> over 48",
> I am not sure this is possible with "normal" equipment.
> Taken literally that would mean an accuracy of .00002 per inch!
> {My ground straight edge is .002 per manf.}
> Do the "big boy" CNC builders achieve this kind of tolerance?
>
> Just to waste some time I checked my 5x8 in X.Y. best I can get
> is +/- .005 over 6',using said straight edge.
>
> The rest of his request was " flat to .005,and less than 8K"
>
> Carl
>
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