Re: gEDA-user: Converting RS274D to RS274X

[Gene Heskett <gene.heskett@xxxxxxxxxxx>]

On Sunday 13 April 2008, Jesse Gordon wrote:
>Gene Heskett wrote:
>> On Sunday 13 April 2008, Jesse Gordon wrote:
>>
>> A list lurker, speaking up as I run EMC2 on a tabletop mill here.
>>
>> This seems like a neat idea Jesse, but can gerbv show 3D?  RS-274-D, from
>> NIST, as interpreted by late versions of EMC2, can describe 9 different
>> axis's & gerbv would seem to be at most a 2D display, possibly with
>> tightly spaced overlays that can be laid on or peeled off.
>>
>> I'm currently setup to do 4 axis's, with the 4th being a "rotate the work
>> surface" using the X axis as the axle to turn on, although I can lay the
>> rotary table down and use it to present the end of the workpiece to the
>> cutter tool too.
>>
>> I'd be interested in seeing such a 3+D display, although my well aged mind
>> cannot well grasp how it might be done, let alone suggest how to do it.
>
>Wow, I didn't know about multiple dimensions on RS275D. We here in the
>PCB world pretty much just use it as a 2d photoplotter format.
>-Jesse
>
:)  Yes, but a utility to extract, and make gcode out of the copper pattern 
removal, would be a very useful utility.  Even if we have to edit the output 
to insert the scale factors and other housekeeping functions a gcode file 
should contain, we would be a long way down the road to automating the 
process.  For my own machine, an HF Micromill, it would be slow indeed as my 
max spindle speed is 2500 rpm.  Depth of cut control when changing tools is 
also a major problem because tool projection depends on how tightly the 
collet is pulled.

This, for pcb carving work, would demand we take it someplace where the tool 
can be measured by setting it down on a homing switch and rezeroing the Z 
axis before continuing.  But the outline cutting, done with a 10 mill bit or 
smaller, would be code very similar to running the copper pattern through 
potrace.

I have seen boards where the copper wasn't disturbed except for the removal of 
the outline, which of course leaves large areas of copper that isn't 
connected to anything, and which may not be what the circuit needs because of 
stray capacitance.  There are no doubt other considerations, but they are 
only more lines in the software.  And this way is chemistry free.

-- 
Cheers, Gene
"There are four boxes to be used in defense of liberty:
 soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
"...if the church put in half the time on covetousness that it does on lust,
 this would be a better world."  - Garrison Keillor, "Lake Wobegon Days"


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