Re: Lathe conversion software

--- In CAD_CAM_EDM_DRO@yahoogroups.com, "Dave" <nseaguy2001@y...>
wrote:

>
>
> I am converting a lathe, a 9x20 asian clone to be exact. Its

purpose

> will mainly be to make 4 parts, all are aluminum, but they are
> threaded. I need to be able to cut a 1.375-20 unef class 2 thread.

I

> would like to cut these threads at least around 1k rpm, witch means

i

> need about 50 IPM of travel, its doable, i think. i have a nice
> preloaded 6mm pitch ballscew i am going to use for the Z axis, i

will

> be cutting it and OD grinding it for bearing journals.
>
> What software is best for controling this Mach2 or DeskCNC? do they
> both do multiple pass threading? ID and OD. I am not planing on
> cutting multiple lead threads at any time.

The DeskCNC 2nd generation controller has presently implemented
threading with the API only. There is a sample user application
(available in VB) that enables axis slaving to a spindle encoder
(quadrature) position. The project source files and the .exe are
available.

You can change spindle speed before, during or after taking a pass
and the subsequent threading cuts will still be accurate. If the
machine spindle rpm lugs down or even stalls during cutting, your
position is maintained. Simply backoff in X, and take a lighter pass.

We expect that the directly accessible G-code command blocks will be
completed within a week or so. These will support multiple axis
following for tapered threading.

> Also if i use desk cnc do both ballscrews need to be the same pitch?

No. This is only required for hardware interpolation of arcs. If
the axis lead pitches are different, arcs are interpolated in
software (at system resolution), prior to transmission to the
controller. This difference between hardware and software
interpolation of arcs is transparent to the metal cutting user.

Fred Smith - IMService
http://www.cadcamcadcam.com/hobby