RE: [CAD_CAM_EDM_DRO] CNC turning

Hi Michael:

The conventional axes on a lathe are the pooposite of what you have described. That is, +X is away from the workpiece centerline, -X is towards the workpiece centerline, +Z is away from the chuck, and -Z is towards the chuck.

This fits the mill model also, as the Z is in line with the spindle axis on either lathe or mill.

______________________________________
Andy Wander

-----Original Message-----
From: CAD_CAM_EDM_DRO@yahoogroups.com [mailto:CAD_CAM_EDM_DRO@yahoogroups.com] On Behalf Of Michael Fagan
Sent: Tuesday, February 02, 2010 1:48 PM
To: CAD_CAM_EDM_DRO@yahoogroups.com
Subject: Re: [CAD_CAM_EDM_DRO] CNC turning

There really isn't anything different about a lathe than a mill. Just
visualize the part as though in section (cut down the axis of rotation).
From there it's just like milling, where x is towards and away from the
headstock and z is towards and away from the centerline of the part. The
location of the tool tip is typically referenced against the centerline of
the part and the face. Since you can't actually touch off the centerline,
you touch off the tool to the edge of a known diameter (either a gauge pin
or your workpiece that you have measured with a micrometer) and then add or
subtract the radius to get the centerline. Once you have it all set up, a
rapid move in z followed by a feed move in x will turn the part to the
radius equal to the z position. A rapid move in x followed by a feed move
in z will face the part at that x location. To drill a hole, mount a drill
in the toolpost and rapid to the centerline, then make a series of x moves
as necessary. Depending on what your control supports, you may be able to
use the canned cycles if you switch it to z axis moves instead of z axis
(which is what you'd use in a mill).

In order to thread on the lathe, you need a spindle encoder with an index
pulse to sync the spindle and x axis feeds.

On Tue, Feb 2, 2010 at 13:34, Jack <freshwatermodels@...> wrote:

>
>
>
> Having built a cnc router and retrofiting CNC to a minimill I now want
> to retrofit a lathe to cnc.
>
> I can accomplish the mechanical end of the conversion but I have never
> worked with a cnc lathe or programming it.
>
> Does anyone know of any good web sites for learning about cnc lathe
> operation and programing?
>
> Although I will most likely try to use either Lazycam or Visualmill to
> generate toolpaths/G code I want to learn a little about manual
> programing . Lazycam seems a bit cryptic and I will have to view the
> tutorial intro a few times to see if I can figure it out. If not I
> will opt for Visualturn.
>
> I watched one of the Mach3 tutorials but was more confused by it than
> when I started.
>
> Any links and/or suggestions on how/where to learn about cnc turning
> would be appreciated!
>
> Jack
>
> [Non-text portions of this message have been removed]
>
>
>


[Non-text portions of this message have been removed]



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