Hobby, 3D, Relief, CNC  

[ Új üzenetek · Tagok · Fórumszabályzat · Keresés · RSS ]
Oldal 11 / 51«129101112135051»
A fórum moderátora: Amatőr, KisKZ, tweakie 
Fórum » Only in English » Technologies » Diode Lasers. (Using Diode Lasers with CNC Machines.)
Diode Lasers.
JJWMACHINECO Dátum/Date: Szerda, 2012-11-07, 13:26 | Üzenet/Post # 201
komoly tag
Csoport/Group: Felhasználók
Üzenetek/Posts: 443
Kitüntetések/Medals: 5
Hírnév/Fame: 2
Helyzet/Status: Offline
I did another one yesterday where I ran the same image in Corel Photo Paint and converted it to B&W using Jarvis with a threshold of 0, saved it as a .bmp and ran it through PVC at the settings I described before and it came out like it should. Dave, I was using John's program PicDither to convert it to B&W. You may be right, but looking at the g-code no matter what depth I set PEP at, it only had full Z depth or Z zero depth in the code, nothing in between. The differences I seen in the g-code with PVC and PEP is the retracts where white is. I always had the PP set for PVC to output all three axis's on each line. I don't think that makes a difference, but it may effect how Mach runs the code based on CV settings. John and Dave, what's your opinion on that? I did not try Corel conversion and run it through PEP yet. John, which process do you recommend in PicDither to convert these clipart images to B&W? Like I said, I used the first one on the list which is Threshold.

Jeff


Extensivly Re-worked/Re-designed/Modified Servo K2CNC KG-3925 and the Mini Laser Engraver
 
Dave Dátum/Date: Szerda, 2012-11-07, 14:13 | Üzenet/Post # 202
aktív tag
Csoport/Group: Felhasználók
Üzenetek/Posts: 192
Kitüntetések/Medals: 1
Hírnév/Fame: 0
Helyzet/Status: Offline
Hi Jeff,
Right click on the image file and select properties. The summary tab will show you the bit depth, 1 is a real b/w image, 8 is greyscale. As far as the gcode goes, I was thinking that the transition from dark to light wasn't just a movement in z by itself, but a movement in z over some distance in x such that it's a gradual change ( a ramp ) in z so that the laser doesn't immediatly turn off. I haven't tried a b/w image yet, might have some time to do that later this afternoon.

Dave
 
tweakie Dátum/Date: Szerda, 2012-11-07, 14:34 | Üzenet/Post # 203
alapvető tag
Csoport/Group: Adminisztrátorok
Üzenetek/Posts: 972
Kitüntetések/Medals: 6
Hírnév/Fame: 5
Helyzet/Status: Offline
Hi Guys,

If you dither an image or otherwise reduce the image to 1 bit then the laser would only be turned on or off as there are no in-betweens to be considered.

Just a thought.

Tweakie.


Success consists of going from failure to failure without loss of enthusiasm.
 
Dave Dátum/Date: Szerda, 2012-11-07, 14:38 | Üzenet/Post # 204
aktív tag
Csoport/Group: Felhasználók
Üzenetek/Posts: 192
Kitüntetések/Medals: 1
Hírnév/Fame: 0
Helyzet/Status: Offline
Just ran a quick pass with pep and a real b/w image. Didn't change my settings stuff, so black is C-.058 and white is C0:
X0.11
Y7.29 C0
Y7.28 C-0.058
Y7.27 C-0.058
Y7.26 C-0.058
Y7.25 C-0.058
Y7.24 C-0.058 <- black here
Y7.16 C0 <- ramps to white over a y distance of .08" (y7.24 to y7.16)
Y7.15 C-0.058 <- ramps from white to black over y of .01"
Y7.14 C-0.058
Y7.13 C-0.058
Y7.12 C-0.058
Y7.1 C0

PVC B/W gcode for the same image looks like this:
N510C-0.0013 <- black here
N520C0.0003 <- retract w/o movement in the raster direction
N530Y3.2881 <- move to new position
N540C-0.0013 <- plunge w/o movement in the raster direction
N550Y3.0057 <- black here for .2824"
N560C0.0003 < retract w/o movement in the raster direction

Dave
 
tweakie Dátum/Date: Szerda, 2012-11-07, 14:45 | Üzenet/Post # 205
alapvető tag
Csoport/Group: Adminisztrátorok
Üzenetek/Posts: 972
Kitüntetések/Medals: 6
Hírnév/Fame: 5
Helyzet/Status: Offline
Hi Dave,

That makes it clear - I understand the problem you are facing now.

Tweakie.


Success consists of going from failure to failure without loss of enthusiasm.
 
JJWMACHINECO Dátum/Date: Szerda, 2012-11-07, 15:07 | Üzenet/Post # 206
komoly tag
Csoport/Group: Felhasználók
Üzenetek/Posts: 443
Kitüntetések/Medals: 5
Hírnév/Fame: 2
Helyzet/Status: Offline
Your right Dave.

I never thought to check that and only assumed I was getting a B&W image when dithering it in PicDither. What's the old saying? Assumption is the mother of all screw ups. fool

I checked the bit of the original gif image and it was 8bit. I brought it into John's re-sizing program and saved it as a jpg and it showed 24bit. Dithered threshold in PicDither and saved it as a bmp and it showed it as 32bit. Strange how it went from 8bit to 32bit. No wonder I could not get it to pulse correctly at any depth.

John, you see how Dave showed how PVC retracts, but now I know I was not dealing with a 1bit B&W, I will try again with PEP. I will run the image I processed in Corel, it shows it as 1bit.

Jeff


Extensivly Re-worked/Re-designed/Modified Servo K2CNC KG-3925 and the Mini Laser Engraver
 
Dave Dátum/Date: Szerda, 2012-11-07, 15:34 | Üzenet/Post # 207
aktív tag
Csoport/Group: Felhasználók
Üzenetek/Posts: 192
Kitüntetések/Medals: 1
Hírnév/Fame: 0
Helyzet/Status: Offline
I think that if the gcode movement in z is only one step up/down and it moves in the raster direction while retracting that you'll still get some smearing as the z-step won't happen until it's halfway through the raster step distance of .010" or whatever you're using. Mach doesn't output a step pulse until movement exceeds a one-step distance. For me, that's .00025" - I can mdi less than that, but the stepper doesn't move at all until the distance exceeds .00025". But I haven't tried a real burn with a b/w image & pep so I don't know for sure.

Dave
 
tweakie Dátum/Date: Szerda, 2012-11-07, 15:48 | Üzenet/Post # 208
alapvető tag
Csoport/Group: Adminisztrátorok
Üzenetek/Posts: 972
Kitüntetések/Medals: 6
Hírnév/Fame: 5
Helyzet/Status: Offline
Just another thought...

'PicLaser' generates the GCode differently (as it is intended for 1 bit working).

G21
F1016
M10P1
G01 X0 Y0
G01 Y0.25400
G01 X115.951
M11P1
G01 X115.951
G01 X115.824
M10P1
G00 X115.824
G01 Y0.50800
G01 X120.65
M11P1
G01 X120.65
G01X120.777
M10P1
G01 X120.777
G01 X124.714
M11P1

Although I use M11P1 for ON and M10P1 for OFF that could be replaced in the PicLaser software settings to your necessary Z Axis moves.

Tweakie.


Success consists of going from failure to failure without loss of enthusiasm.
 
JJWMACHINECO Dátum/Date: Szerda, 2012-11-07, 16:10 | Üzenet/Post # 209
komoly tag
Csoport/Group: Felhasználók
Üzenetek/Posts: 443
Kitüntetések/Medals: 5
Hírnév/Fame: 2
Helyzet/Status: Offline
John,

I'm running it right now with a setting of Z-.0015 depth and zeroed Z at -.0005 from where it jumps to 5V so when it would go to Z-.0015 it will pulse. It's coming out like is should and will post a pic. later. I did edit the file to retract to a positive .0015 instead of Z0, but It may not have been necessary. I probably got you on another wild goose chase again and if I did, I'm sorry. You and Dave may get different results with the DAC circuit and a retract and plunge on a separate line may help. It may improve the results with my encoder also.

Jeff

Hozzáadva (2012-11-07, 5:10 PM)
---------------------------------------------
Here is the link to the original clip art picture for experimentation. http://etc.usf.edu/clipart/54900/54900/54900_train.htm#.UJpiU29BFyV

Jeff


Extensivly Re-worked/Re-designed/Modified Servo K2CNC KG-3925 and the Mini Laser Engraver
 
picengraver Dátum/Date: Szerda, 2012-11-07, 22:08 | Üzenet/Post # 210
Fontos tag
Csoport/Group: Felhasználók
Üzenetek/Posts: 528
Kitüntetések/Medals: 3
Hírnév/Fame: 2
Helyzet/Status: Offline
Jeff,
My present thinking is that the lines in the train were from something else other than PEP code. I don't know what yet, but I know that PEP will correctly output Z values based on pixel color. I will add this weekend the ability to set a different retract level for Z zero as we have discussed. I can see where this makes sense for laser code. It is not good for engraving code, especially for lithophanes.

PicDither does not save as a 2 bit (bitonal) image. It saves as a grayscale with only two colors - black and white. This will make no difference in gcode output. Black will still output at whatever full cut depth you set, and white will output at zero. Threshold is the correct setting to use for black and white. The other settings will all produce dithered code, which is an entirely different thing.

From looking at Dave's post of PVC code, that type of code will run in Exact Stop mode, not CV mode. Only one axis will move at a time. It will also run much more slowly and jerkily. This is, as Tweakie pointed out, similar to the way PicLaser runs now. I have not tried to finalize PicLaser yet as I am still trying to improve it (too darn slow for my liking).

I think you might can run PEP code with Mach3 in Exact Stop mode to see what I am trying to explain. The 'ramping' between pixels should be negligible. I have never thought to test and analyze this myself, but I will try to do so this weekend.

I have no problems setting up PEP to run whatever type of code you guys want to try. We are all experimenting with this, and learning as we go. So don't hold back with questions and concerns. What I am thinking now is to leave PEP alone as to the gcode it produces now for grayscale, and add any special code needed to make black and white code run better as a separate selected output (hope this is clear). It's just a matter of adding a check box to tell it which code to output. For testing, I would limit it to only running horizontally or vertically as we develop the code. Running at an angle is more complicated.

Regards All,
John


I paint with a blue light beam.
 
JJWMACHINECO Dátum/Date: Szerda, 2012-11-07, 22:17 | Üzenet/Post # 211
komoly tag
Csoport/Group: Felhasználók
Üzenetek/Posts: 443
Kitüntetések/Medals: 5
Hírnév/Fame: 2
Helyzet/Status: Offline
Well, I thought it was coming out like it should. It's better then before, but still has the lines in it. First one is the result of running the Corel dithered 1bit image in PEP and the second one is same image run in PVC. I used the same Z.0015 retract and Z-.0015 depth settings in both programs.

Jeff



Csatolások/Attachments: 7552206.jpg(149Kb) · 9177375.jpg(141Kb)


Extensivly Re-worked/Re-designed/Modified Servo K2CNC KG-3925 and the Mini Laser Engraver
 
picengraver Dátum/Date: Szerda, 2012-11-07, 23:15 | Üzenet/Post # 212
Fontos tag
Csoport/Group: Felhasználók
Üzenetek/Posts: 528
Kitüntetések/Medals: 3
Hírnév/Fame: 2
Helyzet/Status: Offline
Jeff,

OK, don't do any more testing with black and white images until I can change the code. It IS related to the Mach3/CV ramping issue. When I changed the code sometime back (long before laser testing) to rapidly skip over the white areas, it allowed Mach3 CV mode to ramp up and down between pixels of different colors. If doing grayscale, this would probably be barely noticeable, BUT, with only black and white colors, the ramping is over larger distances, and false lines do occur. Dave's analysis was correct. This also explains what you saw with black letters on white background.

Now, how to fix it. I think it will require some minor code changes as we have already discussed - retract before rapid move over white. This will also help grayscale burning, too.

I'm sorry it took me a while to see this. All the clues were there, but it took your laser work to find it. I just ran a test image I used for PicLaser, and this confirmed the problem.

Thanks much,
John


I paint with a blue light beam.
 
Dave Dátum/Date: Csütörtök, 2012-11-08, 03:25 | Üzenet/Post # 213
aktív tag
Csoport/Group: Felhasználók
Üzenetek/Posts: 192
Kitüntetések/Medals: 1
Hírnév/Fame: 0
Helyzet/Status: Offline
John, does that mean that the raster movement during the retract is greater than the inter-pixel distance (the typical .010 stepover)?
If so, that would explain the lines as a one step retract movement would be over a larger x or y distance, and that one step retract would occur near the middle of that x or y move (i think).
Oops, i just re-re-read your update, think it's saying the same thing.... wacko
Dave
 
Amatőr Dátum/Date: Szombat, 2012-11-10, 20:21 | Üzenet/Post # 214
alapkő
Csoport/Group: Adminisztrátorok
Üzenetek/Posts: 2207
Kitüntetések/Medals: 6
Hírnév/Fame: 3
Helyzet/Status: Offline
You, guys made awesome job, congratulations to all!

JJWMACHINECO, Your picture seems like an old newspaper print from 17th century. Do You know a software what can create a similar looking picture from a photo?


H1i.hu
 
Dave Dátum/Date: Szombat, 2012-11-10, 23:45 | Üzenet/Post # 215
aktív tag
Csoport/Group: Felhasználók
Üzenetek/Posts: 192
Kitüntetések/Medals: 1
Hírnév/Fame: 0
Helyzet/Status: Offline
I use Gimp's difference of gaussians edge detection filter and then Gimp's threshold tool to get a sort of line-drawing from a photo. I have to play with both until I get something that is acceptable. In the past, I've used it with vcarve-pro's vcarve toolpathing, haven't yet tried it with the laser though.

Dave
 
JJWMACHINECO Dátum/Date: Vasárnap, 2012-11-11, 13:30 | Üzenet/Post # 216
komoly tag
Csoport/Group: Felhasználók
Üzenetek/Posts: 443
Kitüntetések/Medals: 5
Hírnév/Fame: 2
Helyzet/Status: Offline
Corel Draw has a tracing function with all kinds of different settings/options where it will turn a raster image into a vector line drawing and then you can export out as a DXF. I played around with it a little, but have not cut or lasered anything with it.

Jeff


Extensivly Re-worked/Re-designed/Modified Servo K2CNC KG-3925 and the Mini Laser Engraver
 
Amatőr Dátum/Date: Vasárnap, 2012-11-11, 13:59 | Üzenet/Post # 217
alapkő
Csoport/Group: Adminisztrátorok
Üzenetek/Posts: 2207
Kitüntetések/Medals: 6
Hírnév/Fame: 3
Helyzet/Status: Offline
Thank You boys for hints! I think what I'm looking for is a bit different.
See this picture below:
All the dark places are filled with lines, gives an ancient look. Can I somehow create similar pictures?

Csatolások/Attachments: 1035102.jpg(474Kb)


H1i.hu
 
picengraver Dátum/Date: Vasárnap, 2012-11-11, 15:07 | Üzenet/Post # 218
Fontos tag
Csoport/Group: Felhasználók
Üzenetek/Posts: 528
Kitüntetések/Medals: 3
Hírnév/Fame: 2
Helyzet/Status: Offline
Amator,

No computer can (will) ever replace the masterful hand of the artist demonstrated by your image.

Best Regards Friend,

John


I paint with a blue light beam.
 
Amatőr Dátum/Date: Vasárnap, 2012-11-11, 17:40 | Üzenet/Post # 219
alapkő
Csoport/Group: Adminisztrátorok
Üzenetek/Posts: 2207
Kitüntetések/Medals: 6
Hírnév/Fame: 3
Helyzet/Status: Offline
John, somehow I supposed this answer, just asked if You know something similar. All I tried is far away from this great kind of imagery.

H1i.hu
 
Dave Dátum/Date: Vasárnap, 2012-11-11, 22:16 | Üzenet/Post # 220
aktív tag
Csoport/Group: Felhasználók
Üzenetek/Posts: 192
Kitüntetések/Medals: 1
Hírnév/Fame: 0
Helyzet/Status: Offline
Just a thought..... You might be able to use gimp or corel to convert the photo to a line drawing, and then use vcarve pro's bitmap tracing and quick engrave toolpath to hatch the closed vectors like this image:
Csatolások/Attachments: 5337977.jpg(49Kb)


Az üzenetet módosította/Modified by Dave - Vasárnap, 2012-11-11, 22:26
 
Fórum » Only in English » Technologies » Diode Lasers. (Using Diode Lasers with CNC Machines.)
Oldal 11 / 51«129101112135051»
Keresés:

Copyright HobbyCnCArt © 2016