Helical interp was Re: Cirular interpolation

Tony,

John S is right; more info would be helpful...

Most controls capable of helical interpolation implement it simply:

Just program the circle and ADD a linear "departure" value.

So in the XY plane, a helical move would be: G02 x0y0 i2.25 z-.125

(assumes cutter comp. adjust comp or coords for correct thread depth)
Arc-in and arc out of the move.(depending on the precision needed,
these moves may need to be helical as well).

Adjust x,y and i (or J) to suit your specifics. If your threadmill
has multiple threads, this should do it; otherwise make additional
helical moves to get enough threads.

Hope this helps.

Ballendo

--- In CAD_CAM_EDM_DRO@y..., "Tony Dickson" <antson@c...> wrote:
> Folks,
> I'm having a heck of a time trying to get my milling machine
thread a 4.500" hole with an 8 tpi thread in it. Can anyone tell me
if Bobcad, Vectorcad or Dolphin can generate code for this
particular operation. I think it might also be called helical
interpolation, I'm not sure.
> I got in on the end of the "thread milling" post a while back, I
hope I'm not repeating the same question.
>
> Thanks,
> Tony
>
>
> [Non-text portions of this message have been removed]