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Subject: Re: back to solder paste - cnc dispenser - G-code

From: "Dave Mucha" <dave_mucha@...>
Date: 2004-04-28

Much simplier.

A note is that the G0 is a G and a ZERO, not the letter 'O'

My CNC software needs G00 (G-zero-zero) but this is still a
simplier way.


A note of explanation is that the G00 is a go-to for the X/Y axis.

the drilling code
G81 Z-.1 F30 R .1

is a program call to G81 (drill command)
Z-.1 is the Z axis command to go to -.1
F30 is the feed rate to be 30% of the maximum speed of the axis.
R .1 is what is called a release point or a point above the part so
the tool has clearance and moving the part will not let the drill hit
any clamps or the part.

Another note is that the G81 will repeat ever time an new X/Y line is
read. so there is no need to jump to another for more drill
instructions.

I currently use a bunch of different feeds and speeds on my holes so
have created a table of different actions so the jump works best for
me.

Dave







--- In Homebrew_PCBs@yahoogroups.com, "ballendo" <ballendo@y...>
wrote:
> Here's a simpler way.
>
> Use search and replace in a word processor to put a G0 in front of
> each X. (Search for "X" and replace with "G0 X")
>
> Put the G81 canned drill cycle at the beginning:
>
> G81 Z-.1 F30 R .1 (go down to -.1 at 30 units/minute, come back up)
> (to .1 above board at rapid rate.)
>
> That's it. The g81 drilling cycle will repeat at each hole location
> in the list below.
>
> Ballendo
>
> P.S. You'd have your "safety block" (init commands) at the
beginning
> of the file, and your "clean up and get out commands" at the end.
But
> these would always be the same for a given board thickness and
type.
> So with one search and replace, and three cut and pastes, you have
> converted an excellon file to a g code file. If you have different
> drill sizes, you'd add a search and replace to change the excellon
> toolchange to the Gcode toolchange.
>
> P.P.S. You won't have to do even this with my machines; as they
> understand the excellon file directly.
>
> --- In Homebrew_PCBs@yahoogroups.com, "Dave Mucha"
<dave_mucha@y...>
> wrote:
> > here is a small snip of one of mine.
> >
> > X009200Y004950
> > X010400Y002250
> > X009400Y002250
> > X008400Y002250
> > X007400Y002250
> > X006400Y002250
> > X005400Y002250
> > X004400Y002250
> > X003400Y002250
> > X003400Y007050
> > X004400Y007050
> > X005400Y007050
> >
> >
> > Cartesian coordinates in X and Y that exactly line up to the
drill
> > holes.