Re: [CAD_CAM_EDM_DRO] Newbie: Two halves of simple die not aligning properly - Long

Try drilling four holes in a square or rectangular pattern. The larger,
the more accurate you can be.
Measure the diagonals between the holes. If the measurements aren't
equal, your axes aren't perpendicular to each other.

a b
----------
|* *|
| |
|* *|
----------
c d

Measure c to b, then d to a.

Regards,
JJ



On 18-Aug-2005, at 22:07, kaptainkarst wrote:

> Very new to both the software and the machine and trying to learn
> where to start the troubleshooting.
> I have a Shopmaster Elderado Bridgemill (3 in 1).
> I use Mach2 and Sheetcam.
> The machine is calibrated well with Mach2 (~.002 after several X and Y
> commands then return to zero).
>
> I have created (for testing) a very simple DXF file that contains 3
> drill holes for indexing, a horizontal line as well as one vertical
> line.
>
> Half A:
> I import the dxf file into Sheetcam, create the drill gcode for the 3
> holes, save the file and then create the mill gcode for the horizontal
> and vertical lines and save the file.
>
> Half B:
> I then use the same dxf file and select the horizontal MIRROR option
> and repeat the above processes for creating the other half of this
> simulated die and save the files for half B.
>
> I then open Mach2, load the Gcode for the drill (indexing holes) and
> run the program (this is after indicating the workpiece in the vice
> and setting zeros on all three axises). After the 3 holes are
> drilled, it returns to zero, I remove the drill bit and replace with
> an end mill and reset the z axis zero (x and y are still the same).
>
> I then load the second half into the vise and indicate the corner to
> zero just like I did with the first half. I load the "Half B" drill
> gcode, let it run, it returns to zero and I change the drill bit out
> for an end mill and reset the Z axis zero. I then run the mill
> process for half B.
>
> When I put the two halves together, the index holes line up properly
> but the two milled slots are slightly skewed from each other (approx.
> 1/8" over 4" of travel).
>
> I thought sheetcam was causing my error, so I created half B using the
> mirror command in Autocad and got the same results after running each
> dxf file through sheetcam.
>
> I don't understand why the 3 randomly spaced index holes line up fine
> (put pins in the holes and can put the other half over the pins - no
> slop in the holes or pins) but the milled slots are skewed. I would
> have thought if there was an error in the travel of the machine, that
> the index holes would reflect this as well and they would not line up.
>
> Does this make sense?
>
> Where is a good first place to start looking for what is causing my
> error?
>
> Thanks,
> Jim
>
>
>
>
>
>
>
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