Re: [CAD_CAM_EDM_DRO] Re: True 4 axis

Randy wrote:

> I don't follow "perfect raised circle", William. Do you mean "perfect"
> when looking at a side view of the rod, or "perfect" as if the rod was used
> as a rolling die and the resultant impression viewed?
>
> You don't need a rotary axis for the former at all, just X-Y-Z. The circle
> will be perfectly round when viewed down the Z axis, and the sidewalls will
> be also parallel to the Z axis.
>
> You don't need the Y axis for the latter at all, just X-Z-A. The
> impression in the material will be perfectly round and the sidewalls of the
> impression will be vertical.

Actually, the sidewalls in the latter case will not be vertical unless
you use an endmill of zero diameter. Cutter compensation for an
endmill aligned with the Z axis has to be done in the X and Y axis.
If you try to do cutter compensation with a rotary axis, you get a
distorted shape and/or sloping walls.

Chris

--
Christopher C. Stratton, stratton@...
Instrument Maker, Horn Player & Engineer
22 Adrian Street, Somerville, MA 02143
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