CAD CAM EDM DRO - Yahoo Group Archive

Re: PCB routing with CNC milling machine....

Posted by Fred Smith
on 2003-10-28 06:27:32 UTC
--- In CAD_CAM_EDM_DRO@yahoogroups.com, Kim Lux <lux@d...> wrote:
> On Mon, 2003-10-27 at 10:46, Jon Elson wrote:
>
> > The Gerber file IS "gcode", alias RS-274D. It is in a very
specialized
> > style,
> > with suppressed leading zeros and no decimal point.
>
> OK, good to know that.
>
> > The original Gerber
> > photoplotters used off the shelf CNC controls to move thew XY
stage,
> > and therefore were programmed in Gcode.
>
> That makes sense.

Jon keeps posting this nonsense and misleading people into thinking
it is just a snap of the fingers to be able to write your own CNC
machine programs from Gerber files. Note: Extended Gerber is not G-
code as used for CNC machining. It is not documented in the RS-274D
standard, but rather RS-274X, which is a whole different bird. The
flavor used by most modern creators of Gerber files does not even
match the RS-274X standard, and most differ considerable between ecad
design programs. ( ecad- electronic cad design program, ie Eagle, etc)

RS-274X is available for download from the web.

There are several issues that the free and most of the expensive e-
cad programs do not address:

1) drilling and spot drilling for hole location
2) mirror image for the bottom sides of the boards
3) offset for tool size and detection of overlapping toolpaths if
somebody mistakenly uses a 1/8 end mill instead of a 60 degree
engraving point.

Both DeskPCB $95 and DeskCNC $300 have these capabilities, and both
can also save the trace outlines as DXF files, if you want to do
additional routing or processing of the data.

http://www.imsrv.com

Some issues for consideration in making a machine to mill PCB's are:

Spindle speed. The cutter action area is a very small diameter and
even though the board material is very abrasive and has a low
machinability rating, the tiny cutter diameter dictates a very high
spindle speed to enable cutting, rather than dragging, through the
material. Very few have reported any success at speeds below 10,000
rpm, and 20,000 - 30000 rpm is usually much better. Higher speeds
require expensive spindles that are not really within the budget of
most hobbyist/home shop users.

Material flatness is also an issue. The boards should be clamped to
a stiff, flat surface. They will flex a lot, and edge toe-clamping
will suffice for small boards. For larger boards 12 x 12 and up, you
should plan on a good vacuum hold down system. Surface contact height
adjustment (like a sewing machine foot) is not as useful as with
engraving, due to the fragile nature of the thin traces left behind.

Machined boards are usually easy to spot because of the wide expanses
of unconnected copper that are left behind. It is really only
necessary to isolate the traces and not to fully remove the copper
cladding in between, as is usually done with chemical etching
processes. Sometimes this material is removed. For most of us in
the CNC metal machining world, this is done with pocketing. Some may
be familiar with the term "erasing", which is essentially the same
process.


Fred Smith - IMService
We are THE source for lowcost Cad-Cam
http://www.imsrv.com/hobby for group discounts and specials.

Discussion Thread

fuddham 2003-10-26 05:44:41 UTC VFD for a 15HP CNC lathe caudlet 2003-10-26 06:37:39 UTC Re: VFD for a 15HP CNC lathe Marv Frankel 2003-10-26 07:12:53 UTC Re: [CAD_CAM_EDM_DRO] Re: VFD for a 15HP CNC lathe fuddham@a... 2003-10-26 07:35:52 UTC Re: [CAD_CAM_EDM_DRO] Re: VFD for a 15HP CNC lathe caudlet 2003-10-26 07:48:15 UTC Re: VFD for a 15HP CNC lathe David A. Frantz 2003-10-26 08:36:58 UTC Re: [CAD_CAM_EDM_DRO] Re: VFD for a 15HP CNC lathe vavaroutsos 2003-10-26 09:09:51 UTC Re: VFD for a 15HP CNC lathe Doug Fortune 2003-10-26 17:37:55 UTC Re: [CAD_CAM_EDM_DRO] Re: VFD for a 15HP CNC lathe fuddham@a... 2003-10-26 17:52:59 UTC Re: [CAD_CAM_EDM_DRO] Re: VFD for a 15HP CNC lathe Raymond Heckert 2003-10-26 19:23:27 UTC Re: [CAD_CAM_EDM_DRO] VFD for a 15HP CNC lathe Markwayne 2003-10-26 20:22:17 UTC Re: [CAD_CAM_EDM_DRO] Re: VFD for a 15HP CNC lathe Marv Frankel 2003-10-26 21:00:09 UTC Re: [CAD_CAM_EDM_DRO] Re: VFD for a 15HP CNC lathe Jon Elson 2003-10-26 21:35:01 UTC Re: [CAD_CAM_EDM_DRO] VFD for a 15HP CNC lathe Jon Elson 2003-10-26 21:41:22 UTC Re: [CAD_CAM_EDM_DRO] Re: VFD for a 15HP CNC lathe fuddham@a... 2003-10-27 04:40:29 UTC Re: [CAD_CAM_EDM_DRO] Re: VFD for a 15HP CNC lathe dan 2003-10-27 08:08:40 UTC Re: VFD for a 15HP CNC lathe Chuck Knight 2003-10-27 08:08:58 UTC Re: [CAD_CAM_EDM_DRO] Re: VFD for a 15HP CNC lathe Kim Lux 2003-10-27 08:09:11 UTC PCB routing with CNC milling machine.... anti_entropics 2003-10-27 08:09:12 UTC Re: VFD for a 15HP CNC lathe Jerry Kimberlin 2003-10-27 08:09:41 UTC Re: [CAD_CAM_EDM_DRO] Re: VFD for a 15HP CNC lathe Jon Elson 2003-10-27 09:47:16 UTC Re: [CAD_CAM_EDM_DRO] PCB routing with CNC milling machine.... Jon Elson 2003-10-27 09:50:18 UTC Re: [CAD_CAM_EDM_DRO] Re: VFD for a 15HP CNC lathe Tim Goldstein 2003-10-27 09:58:57 UTC RE: [CAD_CAM_EDM_DRO] PCB routing with CNC milling machine.... Harvey White 2003-10-27 13:42:02 UTC Re: [CAD_CAM_EDM_DRO] PCB routing with CNC milling machine.... Harvey White 2003-10-27 13:44:49 UTC Re: [CAD_CAM_EDM_DRO] PCB routing with CNC milling machine.... James Cullins 2003-10-27 18:24:20 UTC Re: [CAD_CAM_EDM_DRO] PCB routing with CNC milling machine.... Tim Goldstein 2003-10-27 18:39:50 UTC RE: [CAD_CAM_EDM_DRO] PCB routing with CNC milling machine.... James Cullins 2003-10-27 18:48:18 UTC Re: [CAD_CAM_EDM_DRO] PCB routing with CNC milling machine.... vnegrete@r... 2003-10-27 19:09:39 UTC Re: [CAD_CAM_EDM_DRO] PCB routing with CNC milling machine.... David A. Frantz 2003-10-27 19:29:32 UTC Re: [CAD_CAM_EDM_DRO] Re: VFD for a 15HP CNC lathe John Johnson 2003-10-27 23:06:20 UTC Re: [CAD_CAM_EDM_DRO] PCB routing with CNC milling machine.... Kim Lux 2003-10-27 23:15:20 UTC Re: [CAD_CAM_EDM_DRO] PCB routing with CNC milling machine.... Brian 2003-10-27 23:16:22 UTC Re: [CAD_CAM_EDM_DRO] PCB routing with CNC milling machine.... Jerry Kimberlin 2003-10-27 23:16:32 UTC Re: [CAD_CAM_EDM_DRO] PCB routing with CNC milling machine.... Jon Elson 2003-10-27 23:35:39 UTC Re: [CAD_CAM_EDM_DRO] PCB routing with CNC milling machine.... turbulatordude 2003-10-28 03:32:52 UTC Re: PCB routing with CNC milling machine.... turbulatordude 2003-10-28 03:43:54 UTC Re: PCB routing with CNC milling machine.... James Cullins 2003-10-28 03:53:16 UTC Re: [CAD_CAM_EDM_DRO] Re: PCB routing with CNC milling machine.... James Cullins 2003-10-28 03:55:52 UTC Re: [CAD_CAM_EDM_DRO] PCB routing with CNC milling machine.... turbulatordude 2003-10-28 04:27:43 UTC Re: PCB routing with CNC milling machine.... fuddham@a... 2003-10-28 05:10:45 UTC Re: [CAD_CAM_EDM_DRO] Re: VFD for a 15HP CNC lathe Fred Smith 2003-10-28 06:27:32 UTC Re: PCB routing with CNC milling machine.... James Cullins 2003-10-28 07:12:53 UTC Re: [CAD_CAM_EDM_DRO] Re: PCB routing with CNC milling machine.... Kim Lux 2003-10-28 07:22:00 UTC Crashing CNCs: what gives ? IMService 2003-10-28 08:04:54 UTC Re: Crashing CNCs: what gives ? Vince Negrete 2003-10-28 08:24:46 UTC Re: [CAD_CAM_EDM_DRO] Crashing CNCs: what gives ? Harvey White 2003-10-28 08:59:02 UTC Re: [CAD_CAM_EDM_DRO] PCB routing with CNC milling machine.... Harvey White 2003-10-28 09:00:10 UTC Re: [CAD_CAM_EDM_DRO] PCB routing with CNC milling machine.... Jon Elson 2003-10-28 09:05:26 UTC Re: [CAD_CAM_EDM_DRO] PCB routing with CNC milling machine.... Jon Elson 2003-10-28 09:06:41 UTC Re: [CAD_CAM_EDM_DRO] Re: PCB routing with CNC milling machine.... stevenson_engineers 2003-10-28 09:08:59 UTC Re: Crashing CNCs: what gives ? Jon Elson 2003-10-28 09:17:23 UTC Re: [CAD_CAM_EDM_DRO] Crashing CNCs: what gives ? Jon Elson 2003-10-28 09:45:43 UTC Re: [CAD_CAM_EDM_DRO] Re: PCB routing with CNC milling machine.... Fred Smith 2003-10-28 12:03:46 UTC Re: PCB routing with CNC milling machine.... wanliker@a... 2003-10-28 12:14:00 UTC Re: [CAD_CAM_EDM_DRO] Re: PCB routing with CNC milling machine.... stevenson_engineers 2003-10-28 13:20:12 UTC Re: PCB routing with CNC milling machine.... Alan Rothenbush 2003-10-28 15:03:00 UTC Re: [CAD_CAM_EDM_DRO] PCB routing with CNC milling machine.... David A. Frantz 2003-10-28 19:41:29 UTC Re: [CAD_CAM_EDM_DRO] Crashing CNCs: what gives ? Raymond Heckert 2003-10-28 19:57:53 UTC Re: [CAD_CAM_EDM_DRO] Crashing CNCs: what gives ? Kim Lux 2003-10-28 21:16:36 UTC Re: [CAD_CAM_EDM_DRO] Crashing CNCs: what gives ? David Bloomfield 2003-10-28 21:17:19 UTC Re: Crashing CNCs: what gives ? ballendo 2003-10-29 06:52:26 UTC Re: PCB routing with CNC milling machine.... ballendo 2003-10-29 07:15:47 UTC Re: Crashing CNCs: what gives ? Kim Lux 2003-10-29 07:28:06 UTC Re: [CAD_CAM_EDM_DRO] Crashing CNCs: what gives ? Dan Mauch 2003-10-29 08:09:33 UTC RE: [CAD_CAM_EDM_DRO] Crashing CNCs: what gives ? David A. Frantz 2003-10-29 08:32:26 UTC Re: [CAD_CAM_EDM_DRO] Re: Crashing CNCs: what gives ? ballendo 2003-10-29 09:29:33 UTC Lathes for retrofit was Re: Crashing CNCs: what gives ? Jon Elson 2003-10-29 10:44:14 UTC Re: [CAD_CAM_EDM_DRO] Crashing CNCs: what gives ? David A. Frantz 2003-10-29 21:11:19 UTC Re: [CAD_CAM_EDM_DRO] Lathes for retrofit was Re: Crashing CNCs: what gives ? Kim Lux 2003-10-29 23:22:01 UTC Re: [CAD_CAM_EDM_DRO] Lathes for retrofit was Re: Crashing CNCs: what gives ? Kim Lux 2003-10-29 23:22:02 UTC Re: [CAD_CAM_EDM_DRO] Crashing CNCs: what gives ? Tony Jeffree 2003-10-30 00:29:06 UTC Re: [CAD_CAM_EDM_DRO] Crashing CNCs: what gives ? ballendo 2003-10-30 05:26:20 UTC Lathes for retrofit Erie Patsellis 2003-10-30 07:25:02 UTC Re: [CAD_CAM_EDM_DRO] Lathes for retrofit was Re: Crashing CNCs: what gives ? wanliker@a... 2003-10-30 09:50:54 UTC Re: [CAD_CAM_EDM_DRO] Crashing CNCs: what gives ? David A. Frantz 2003-10-30 12:37:44 UTC Re: [CAD_CAM_EDM_DRO] Lathes for retrofit Kim Lux 2003-10-31 08:20:04 UTC CNC threading: tapping head or T/C holder ? Robb Greathouse 2003-10-31 08:20:17 UTC Re: [CAD_CAM_EDM_DRO] Lathes for retrofit was Re: Crashing CNCs: what gives ? Torsten 2003-10-31 10:32:10 UTC Re: Lathes for retrofit Tony Jeffree 2003-11-01 04:00:56 UTC Re: [CAD_CAM_EDM_DRO] Crashing CNCs: what gives ?