Re: Metric measurements.

One possibility would be to change the unit in your CAD before making
the DXF. My CAD allows me to jump back and forth at will.

But, another problem may be that you have your CNC set to run in
inches. a 5 TPI leadscrew with 1,000 steps per inch will move 1,000
steps per "ONE UNT"

If you set the driver so a 'unit' is a mm, then moving one 'unit'
would be 25.4 steps and not 1,000 steps.

Dave



--- In CAD_CAM_EDM_DRO@yahoogroups.com, "kbucklitch"
<keith.bucklitch@w...> wrote:

> Hi folks
>
> This is my first posting to the group, in the hope that someone will
> be able to assist me.
>
> I create my CAD drawings with TurboCAD. For several years, I have
> produced my drawings using metric (mm) measurements. Before I
> started experimenting with CNC, if I printed the drawing full size,
> then it was printed almost exactly the size of the item (within the
> accuracy of the printer).
>
> To use the drawing to create a toolpath for the CNC cutter, I export
> the drawing initially as a .dxf file. I have then converted the
> file to G-code using two programs - KCam or Simsoft Mach 2. Both
> of these will produce a G-Code script. I then use the software to
> drive the CNC controller. At present, because I am driving my CNC
> control with KCam on an old laptop under Windows 98 (Mach 2 requires
> WinXP.) However, I have found a problem. The CNC driver seems to
> work in imperial units (inches). Hence, a component that should be
> say 20mm long, becomes 20 inches long. This is a little difficult
> on a milling machine which only has around 12" of travel.
>
> In the KCAm Setup/Table Setup menu, it asks if you want (are using?)
> imperial or metric measurements. However, choosing metric in this
> dialogue box does not appear to make any difference to the finished
> size of the article.
>
> Does anyone with experience of these programs - Mach 2 or KCam know
> how I can set them up so as to convert metric .dxf files to metric
> machine codes?
>
> Thanks
>
> Keith