On Wednesday 19 December 2018 01:27:46 David Berndt wrote:

> I could write a big email about this, and I will if you want to, just
> let me know. But I'll jump in here and agree with Chris. You're
> missing out not having a cad/cam package. You're not able to use your
> tools, or your time to optimum effect, and you're not getting the best
> end result that you could possibly get in most cases. Modern CAM
> software outputs some awesome tool paths and is worth having/using.
> Especially for a hobbyist imo.
>
>
> Regards,
> Dave

I guess I'm a stubborn old cuss. Right now a simulated run looks great, 
and its about 280 active lines of code if the comments are skipped. You 
saw the screen snap I posted yesterday.  Can your cad/cam program do 
that in 300 LOC? 100k LOC maybe.

One question remains: I'd like to drill holes for connectors with a 4mm 
dia tool. All are under .625" in dia. The cutter comp section doesn't 
mention the g42 enable blending moves in anything but the xy plane, so 
my question is:

Can I go to the center of a hole with a 4mm tool a half inch above the 
work, enable the g42. and descend to the work on the z axis while the 
comp is being phased in? If I can do that, my backlplot  visualization 
would be considerable more accurate. Right now I'm doing cutter comp in 
the code, but that means the trace is tool_dia undersized visually. 
Those moves then could be incorporated into the SUB at the expense of 5 
seconds of cutting air above the actual cutout, and only have to be 
written once. I don't see any reason why it couldn't work, and the 
radius of these holes isn't long enough to do the "blending" by a 
loooong ways in the xy plane, and being able to do it with a z move 
would be a huge help. Seeing as how its freezing out, and nearly so in 
the shop where this machine is, I may as well find out. And I guess the 
answer is no, no amount of Z is enough. So the calls will have to pass 
the x & y's too and the SUB will need to do more math.

Next question, will it work at all in G91? No, don't even try.
So all my calls to drill holes are now absolute to the map in use.
So the drill a hole call now looks like this:

o130 SUB
G40
M3
F15 (feed rate)
(arrives here at center of hole, change this to take a passed argument 
for radius)
G0 Z#<_ZUP> ( clear work)
G0 X[#2 - 0.3] Y[#3 - 0.3] (move away for G42 blend in)
G42 D15 X[#1 + #2] y#3
G0 Z0
G3 F#4 I-#1 J-0.000 Z#<_ZDN> P9
f15
G0 Z#<_ZUP> (back to clear)
G40
M5

o130 ENDSUB

The extra, cut air moves, to switch the G42 in and out add around 15 or 
16 minutes to the run time. This routine gets called 19 times.

Its expecting 4 arguments, the last one being a feed rate so I can turn 
it down nor nearly straight drilling, the little holes that are almost a 
straight drill can push pretty hard, and there no support under the 
workpiece except where its clamped at the ends. Plus theres now 3 M0's 
in it, to move clamps at one end or the other, and 2 more M0's to allow 
clamps to be loosened and the work re-aligned in case I have to take it 
off the table. So yes, it will need baby sitting but I don't see anybody 
here except me to do it.

The idea is, I put a workpiece a half inch bigger each way than I need on 
the table, and when its done, I take a complete back panel ready for 
parts off the table, needing only a bit of deburring if the tool gets 
dull. But it will be running up to its kneecaps in cutting oil soaked 
swarf. I moved the ac cord from the too flexible, middle of the panel to 
the extreme left end as that puts an S curve into that heavy cord, 
absorbing any panel flexibility by about 99.9 % before it gets to the 
terminals of a 12 volt 1.25 amp supply that runs it all.

Theres 116+ inches of rapids, and 395+" of cutting, on a panel that's 
about 11.875 by 3.125. 320 LOC according to file->property's. I doubt if 
your cad/cam's gcode output can touch that. If it can't write gcode a 
heck of a lot more efficiently than pcb-2-gcode for eagle, it can't play 
in the same ballpark. I don't have an eagle sourced file thats not 
something in the 100k territory for a 1.6" x 2.2" board.

[...]

And I see its up to 53F, so I might hit the shop and try it if my right 
leg will get me up the hill. Except I haven't been out to get my lady 
her daily dose of crosswords from the local fishwrap yet. Some things 
are more important than others. See rule 2 about the boss is always 
right.  :)  So now I have a leg with a pulled muscle, I woke up around 
7ish with a leg cramp, so I've not been getting around the house too 
well all day. Enough to take care of my lady, but not much else.

I don't recommend this business of getting old, its nothing like AARP 
claims it is. I could cheerfully throttle the guy who claims these are 
the Golden Years. Or he could die a long lingering death from COPD like 
my wife is doing.

Thanks David, and have a Merry Christmas. I'm going to go get my lady her 
cross-words, before she uses them on me. :)

-- 
Cheers, Gene Heskett
--
"There are four boxes to be used in defense of liberty:
 soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
Genes Web page <http://geneslinuxbox.net:6309/gene>


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