Re: [CAD_CAM_EDM_DRO] LibreCad/.DXF to G-Code for CNC drill?

On 5/24/2012 12:59 PM, Craig Carmichael wrote:

> Hi,
>
> I've drawn up XY co-ordinates in LibreCAD, for a CNC to drill bolt &
> vent holes in round rotors/plates for my Electric Hubcap 5KW pancake
> motors. (When I couldn't figure out how to do and dupliate things at
> exact angles around a circle, I got good step by step instructions
> from LibreCAD's help forum.)
>
> I suspect there are people here who'll know... Now that I've done the
> drawing, how might I get a G-Code drill program from it?
>
> (Bla bla bla: My CNC drill/router, which I bought from the guy who
> made it maybe 10+ years ago, has no more sophisticated software than
> the G-Code controller. ...Previously, I worked out the co-ordinates
> via sines and cosines in a spreadsheet, and then created the g-code
> program by hand, cutting and pasting each number to where it needed
> to be. Now to make a change I have to do it all over again. Obviously
> I need to start moving into the modern era, so this time I downloaded
> LibreCAD.)
>
> TIA,
> Craig
> http://www.ElectricHubcap.com/

Actually, the cad is the hardest part.
Gcode has drill cycles. Straight drill and peck drilling.
So the code is simply a line with the drill cycle and then a new line
for every hole with the x and y coordinates.
These can be read from the cad.
If you are using Mach3, it has wizards to write some code, including
circular drilling and rectangular drilling.
This is the output of the circular drill wizard:
G0 G49 G40 G17 G80 G50 G90
M6 T15
G20 (Inch)
M03 S600
G90
G00 G43 H15 Z0.10
G73 X6.75 Y2.25 Z-0.50 Q0.20 R0.10 F5.00
X5.625 Y4.1986
X3.375 Y4.1986
X2.25 Y2.25
X3.375 Y0.3014
X5.625 Y0.3014
G80
M5 M9
M30
************
The G73 is the drill cycle. The lines after are the hole coordinates.

If you don't use Mach3, you can download it free, with a run limitation
of the lines of code. (Used to be 150 lines, but I think it's less, now)
The wizards still function and you can use the code it writes.
Note, some wizards come with it and some are shareware with a separate
license fee.


--


Ron Thompson
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