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

I havent' read this whole thread, but in the CAM I use one specifies
"circles as points" when one has the drill size for that hole, eg, 0.140
hole and 0.140 drill, and use circles as geometric forms when one has bit
smaller than hole - eg, 0.560 hole with 0.1875 mill. In the first case, one
just gets a set of points that are the center of the holes to be drilled,
and you spec the kind of drilling. In the second case one gets a toolpath
that is 0.1875/2 inside (you have to spec inside offset or outside offset)
the defined circle.

If you want to send me the dxf, I can convert it for you and send you the
Gcode that my software generates. .. chuckm at 3rivers.net



Hi,

Thanks Brian and Ron for your suggestions, but it looks like I'm not
there yet and am still looking.

Brian, 'Dxf2gcode' says a "point" is an undefined geometric type, and
for circles, it wants to mill around the periphery rather than to go
at any time to the center where I could tell it to drill.

So it looks like a great program for milling, but as far as I can
tell, it can't be used for drilling holes.

---

Ron, I guess what I'm doing is peck drilling. Many (most) of the
commands in your Mach3 example don't seem to match what I've been
using. But I'm not very literate at this stuff so far, and the
software is pretty old. (On the other hand, at least the drilling
co-ordinates are there.)

Here's a sample of what I have, which uses line numbers (and ignores
any lines <100!):

; abs. pos. mode
N101 G90
; go here
N102 G00 x -0.75 y +4.0625
; call hole drilling sequence
N104 M98 P1320 L1
; go next hole
N106 G90 G00 x +0.75 y +4.0625
; call same drilling sequence
N108 M98 P1320 L1
;etc, etc, etc
N109 G90 G00 x +2.037 y +3.594
N110 M98 P1320 L1

;=========
N500 M30
;=========

;hole drilling sequence
N1320 M44 ; wait a couple of seconds

N1330 M98 P1500 L12 ; peck drill multiple times (this was thick steel)

N1380 M99 ; return

N1500 M20 ; drill down (pneumatic - set air pressure for desired push)
N1520 M44 ; drill a couple of seconds
N1530 M21 ; drill up
N1540 M44 ; wait (then loop)
N1550 M99

======================================

>Hi Craig,
>There are a few freeby type dxf to gcode converters about. This one
>works well:
><http://christian-kohloeffel.homepage.t-online.de/index.html>http://christi

an-kohloeffel.homepage.t-online.de/index.html

>Regards,Brian
>--- On Thu, 24/5/12, Craig Carmichael
><<mailto:craig%40saers.com>craig@... <mailto:craig%40saers.com> >

wrote:

>
>From: Craig Carmichael <<mailto:craig%40saers.com>craig@...

<mailto:craig%40saers.com> >

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

<mailto:CAD_CAM_EDM_DRO%40yahoogroups.com>CAD_CAM_EDM_DRO@yahoogroups.com
<mailto:CAD_CAM_EDM_DRO%40yahoogroups.com>

>Date: Thursday, 24 May, 2012, 19:59
>
>
>
>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/>http://www.ElectricHubcap.com/
>
>===

_____

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