Re: [CAD_CAM_EDM_DRO] Re: CNC division

----- Original Message -----
From: "Alan Marconett KM6VV" <KM6VV@...>
> I haven't exactly gotten my head around moving the X, Y and A axis all
>
> On the "little Italy's", do you really have to use X & Y in combination
> with A? I would think just a linear and a rotational axis would
> suffice. If you have a .DXF file of your part (or a similar part file),
> I and perhaps others would like to see it!

The point of this problem is that parts of the tooth are undercut i.e. the
'foot' on the bottom of the 'leg' cannot be got at by a straight plunge cut.
So, to cut such a wheel it will be necessary to coordinate the moves of at
least three axes A, Z, and Y. Lets consider cutting the 'foot' - if we start
with the cutter at the 'heel' (with the 'foot' pointing down with respect to
the cutter), we can cut along the 'sole' by rotating the A axis upwards and
moving the Y axis to keep the cut surface tangential to the rim of the wheel
(but obviously at the length of the 'leg' distant from it). Now, when we get
to the 'toe' 'A' has to suddenly rise together with the 'Z' axis so that the
cutter can run along the 'top of the foot' to reach the 'ankle. Then a
combination of 'Z' and 'Y' moves can run the cutter up the 'shin'. The real
wheel is a little less complicated than a leg but this illustrates the
procedure. Its the combining of the rotary motion of A with a vertical
cutter position and in-and-out of Y which is necessary to get at the
undercuts. I'll do a drawing of an actual wheel as soon as I get a minute
which should make things clearer.
The only involvement of the X axis would be in running the cutter along for
each cut so that I could cut a stack of wheels at once.

Ian
--
Ian W. Wright
Sheffield UK
www.iw63.freeserve.co.uk