My laser engraver from 0 knowledge to 32.461% .... probably

[BobbyW]

Ill be interested in hearing how the linear input affects output..

Yes , i will made some test's tonight , to see how that work properly.
I have a question , i try to find a good answer but , i didn't found any.
My lens are ZnSe 20mm 50.8 focus , and i think it is on middle scale , i mean is not perfect for engrave also not perfect for cutting.
In my head is like , shorter focus length = engraving and longer focus length = cutting .
I have right ? Because i found on my lens , don't have a perfect fixed point , i mean can be tolerated 2-3mm ( i didn't see the proper difference between that interval , the tiny point remain the same)
Thanks 
Bobby

[ArtF]

Bobby:

  Your right but situations vary widely.  A short focal lens ..say 25-50mm
has a very hot tip and very shallow depth of heat. As it gets longer focus
the heat lessens but goes deeper.

  I think of it as a needle being heated. In short focus the center of the needle glows
white hot for maybe 1mm on either side of center. As focus distance increases the length
of the glowing part of the needle increases, but its the same amount of heat
so it doesnt glow as much..

  As to which you need.. depends.

To cut thin pieces a 50mm is great. To cut thick pieces its nice to have a 3" or even 4"
Some materials help you on their own. Acrylic as it burns creates a waveguide for the
radiation and cuts deeper than the focus can really account for. Wood wont do that.

My main laser has a 3" on it and cuts great. It will also engrave up to .25" deep or so
for 3d engraving. My Galvo laser has a focus lens 265mm long ( very long) but can 3d
engrave to at least 1" or more in depth. (Though it cuts my 50 watt to 20watt or so equiv at
the surface. )

  So when it comes to focus, I like to have a short ( 50 or so) and a long( 75 - 100) for
3d engraving. Normal engraving like a photo can be done with pretty much any focus
length with simple adjustment of power and speed. Highest res though is in theory
with the shortest focal length as the tip dot is smallest.

  This is all if your picky.. Ive found almost any focus can do almost any job
but with varying quality of output.

 
Art


 

[BobbyW]

Yea , so i will buy the most long i will get , just to test some differences . On that lens i have the point on simple 10ms shoot at some low power to pass trough paper , is just pass trough but almost invisible in one focus point , i need a magnifier to see the hole, so i think is good for engraving.
Now about my linear vcc circuit , it works realy great , more nice than i expect
The "magic" is done by optocoupler , he work so nice , https://pdf1.alldatasheet.com/datasheet-pdf/view/598737/CEL/PS9151.html the operational i use to filter , voltage folower and to adjust the power , is in full range , i let auggie at 100% power, is so nice to have now so many option to adjust . I was afraid my laser is to powerful to engrave , but was definetly my fault. My first try " just import a photo and generate " no any filter or any adjustment's , and still is decent on that shit material.
I have another question , i buy here a piece of plexiglas , but i think is not acrylic , because i try to cut him and on almost 80% power , he don't pass trough more than 1mm , he just melt him and very bad cut after 3 passes (with or without air assist don't matter on different pressure) . Maybe he's not IR absorbant ? I don't know , i didn't try on other . Is what i found here in France in one storage.
Bobby

//~~~~~~~~~~~~~~~ edit later ~~~~~~~~~~~~~~~~~~~~
Ahh , and now i notice that raster on the end of black region , i forgot to turn more higher frequency on auggie , lol.  Roll Eyes
Remain me on 300Hz on my last test before to change the interface , i rise up to 10k . I will see next how that will work
Thanks for now, i keep testing , i will try on glass and mirror soon.
Bobby

[ArtF]

Hi:

>>Maybe he's not IR absorbant ?

Yeah, some materials look like acrylic, but dont cut at all.. Beware their smoke..

Art

[BobbyW]

Yeah, some materials look like acrylic, but dont cut at all..

Hi Art
Yea i figure out that .
What about that material PMMA, is that acrylic ? They say are acrylic but they have a "special" way to spell the words .
https://www.plaqueplexiglass.com/perspex-chilli-red-frost-s2-4t50/
I made some test on glass , what i can say , working very well .
And.... on 3D engrave , wow , what i can say , working realy well , a realy nice texture .
You will notice the great job on last pass , if they are more than 3 .
Thanks
Bobby

[ArtF]

Bobby:

  To truly amaze yourself, google for "3d grayscale". The results from those are most impressive
and Auggie will make a multipass 3d object from them. Its interesting to see the depth linearity
when doing such an object.
  Looks like you well on your way. Congratulations.

Art

[BobbyW]

  Looks like you well on your way. Congratulations.

Art

Hi.
Not that fast Art , not that fast > Is true , on engraving i try almost everything , and day by day , gett'in better .
I try on glass, back of the mirror , working realy nice , almost all materials i've get.
The problem now is of cutting that's materials.
I try some shapes , and on circles was realy strange .
I try to made the DXP file in Corel Draw , no way to can group all objects > No skills in that type of programs.
After i try in inkscape , create DXF and import in vexx to convert to GCODE> then , on lines work but on circles , no way ,
the laser don't even shoot , only on the big circle i draw,  but interrupted line .
I put the file below , what program i should use and what is the best option ?
Thanks

[ArtF]

Hi Bobby:

  Try this..

1) I Imported the DXF into Vexx using DXF Import.
2) Select all objects by drawing a selection box around them, then selected Edit/Group
3) Press FastGCode Button. Unlselect the feedrate and Z options for laser.
4) File generated as attached.

  When you run such a file, you have to manually do the M3 to enable the laser before
running the file. The circles imported from the DXF as line segments, not circles,
though you coudl use Vexx to convert them to circles by selecting them individually and
using the convert to arcs button. Then group for Gcode output..

  I ran the test file and it runs OK here, make sure you enter a feedarate high enough..

Couple notes.

  All th epevisou work you ide was photo work, Jerk settings may not affect such
work badly. The real test of Jerk Settings is in this type of file. The speed the circles
will achieve is a mixture of requested feedrate, and Jerk from the radius of the
circles. If you find they wont run fast as you wish, raise your JerkLimit substantially
and find the sweet spot where it runs fast enough , but not too fast.

Art

[BobbyW]

Hi Art

   When you run such a file, you have to manually do the M3 to enable the laser before
running the file.

Yes , i figure out that .

The circles imported from the DXF as line segments, not circles

Yes , that i notice , on big circle i saw the interrupted power , so i figure out are not a continuous arc , just small segments.
And on the small circles laser dont even shoot. I will made more test's.

The speed the circles
will achieve is a mixture of requested feedrate, and Jerk from the radius of the
circles.

My feedrate was on maxim is writed in config. 12000 , run ok now when laser move without burn . But when i decrease the percent , i saw the power will drop considerably
//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
I have a question . I open the Gearotic software for curiosity , and i saw there on image processing , is the same AUGS used in Auggie to generate the code but not on same size and less options.
It is possible to have the option to can made that to run also on full screen ? That should very useful , on small screen you can not realy see what truly happen with photo.
Thanks
Bobby

[BobbyW]

Hi
This night made me crazy , I can not rid off on that stupid ellipse. Engraving working fine , i can do almost everything
i want .
The problem is on cutting. and is not about the power, i have a lot for what i try , is about my settings that for sure
First , i try all the speed and mixed , also i figure out what "jerk" do, i hope  :-[
(i didn't figure out what mean , look ahead , and radius settings)
So, If i made one shape , as square and i set some power speed , feed for that , working perfect . How i wish .
If i made a circle, also working. The problem is on different size of circles. On small ones , he don't even burn
also on that circle he like just stop for some ms and made a short gap without burn.
I made a bunch of test's on paper , just above to pass trough , and i figure out , soon the curve going small power decrease radical.
Can be the problem because the motors don't have any reduction rate, Are directly connected on X and Y .
That can be a problem ? They have a lot of power , that why i didn't mount any reduction well.
I can run so fast to almost break my axes , and don't even get on half on load current on motors .
I'm totaly lost now. I give up and go on sleep to clean my head
I put some photo below.
https://youtu.be/csM47s0ysK4
Thanks