Re: one for the math gurus.....Squaring an Axis

Hi Chris.
You could do what I have done, and that is make yourself a
Cylinderical Square. These are about as perfectly square as anyone
would need as in effect their squareness is generated.
To make one, get some thick-walled tube about 5 inch dia and turn
some plugs up that are a good fit in the ends, glue these in position
and mount the tube in you lathe, centre drill each plug and drill
another hole off centre in each plug that can be used to drive it
round to turn this tube between centres. Turn between centres and get
the smoothest finish possible and get it as parallel as you can. Face
each end and chamfer sharp edges. You now have a perfect square that
can be used with confidence.
All the best, Martin

--- In CAD_CAM_EDM_DRO@yahoogroups.com, CL <datac@l...> wrote:
> Setting up an Axis to be truly square on a CNC machine has always
been a
> challenge. It obvioulsy gets a little easier if one is fortunate
enough
> to have a friend or a day job where you can borrow thier precision
> squares and straight edges.
>
> Them babies are big bucks, and I used to be able to borrow one from
> where I used to work, but,.....
>
> Obviously, a "circle" can't be cut into a true circle if an axis is
> skewed, so,
>
> Is there a mathematical equation where one could:
>
> Engrave a "Dial" with degrees, cut it out into a circle, and then
> measure and "map" its actual circular dimensions.
>
> With the above info, could one then take the dimensional "width" of
the
> Gantry ( based on the mounting points or "fulcrum" point as one end
is
> adjusted), and calculate the amount of adjustment that would be
> necessary to *True up* the Circle ??
>
> I'ts all numbers, so there must be a way to do it. I never came
across
> such an equation. I doubt the diameter of such a circle would have
much
> affect, only the differences in its trueness.
>
> Framing Squares really don't cut it, and I'm curious how others go
about
> this with the least amount of fiddling around.....
>
> Thanks,
> Chris L