Re: [Pcb2gcode-devel] autoleveller

[Mathias K. <mk...@gm...>]

Hello Nicola,

 with those changes LinuxCNC accepts the NGC output here as well.

I tried the autoleveller superficially in the LinuxCNC simulator (probe
close is a button) but not on the real mill yet. It seems to interpolate
the tracks well so far, however the initial Z-move after the rapid x/y
to the start of a chain is produced directly in ngc-exporter.cpp:344 and
is not interpolated from the probed Z positions:

[...]
G0 Z0.25000 ( Move Z to safe height )
(PROBECLOSE) ( Close the probe log file )
( Probing has ended, each Z-coordinate will be corrected with a bilinear
interpolation )
(MSG, detach the probe tool)
M0 ( Temporary machine stop. )

M3 ( Spindle on clockwise. )
G04 P0 ( dwell for no time -- G64 should not smooth over this point )
G00 Z0.25000 ( retract )

G00 X2.12901 Y2.17717 ( rapid move to begin. )
==> G01 Z-0.00100   <==
G04 P0 ( dwell for no time -- G64 should not smooth over this point )
o1000 call [#<_0_1>] [#<_1_1>] [#<_0_0>] [#<_1_0>] [2.17717] [2.12901]
[...]


I like the autoleveller feature a lot. Previously I worked with
pcb-gcode for Eagle and a self written tool that generated probe g-code
and accepted the probe log in a second run to modify the z moves in the
pcb-gcode output. That's obviously complicated because files have to be
copied around during the job, so the interpolation within the g-code is
much more elegant. Now that I decided to switch to kiCad, this comes in
perfectly on time, thanks :-).

When I started experimenting with the probing, I noticed that there is a
temperature (?) drift of ~0.1mm if I start the probing several times
after initially powering on the mill. It stabilized after 5~10min of
operation, the second and 3rd probing run produce similar results but
the 1st and second don't. I wonder whether that is just a bug of my
homegrown mill or happens elsewhere, too.
I do need a lot of probing points by the way because I use cheap and
bit-friendly FR2 baseboard. It is not level at all and too flexible to
pin larger pieces down perfectly.

Bye,

 Mathias


On 31.01.2015 17:38, Nicola Corna wrote:
> I've added both solutions in commits 118a9af7d27049b4fdfda8723d2d0bb5349f51c4 and 4bc07773f3c0945a2ca1729eb871f90c621f47a7
> Your patch should fix every bad point and, if it does not work, my patch should still make a correct gcode
> I've tested your gerber's output with LinuxCNC and everything seems to be ok, can you confirm it?
> Can you please tell me if the autoleveller works for you? It's still experimental and any feedback is very appreciated
> Thanks
>
> Nicola Corna
>