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View Full Version : Rastering twice doesn't work for me..?



Joseph Tovar
11-06-2010, 8:05 PM
Hi all,

I've never had a problem with making a cutline, copying it, and pasting it over itself to make the laser run a cut twice, but when I do that with a raster, it doesn't work...it only rasters once.

For example, I created a square cutline(no fill), copied it, and pasted over itself. I sent the job to the laser and it cut once, then went around and cut twice.

I then created another square, filled it with my raster color(no cutline), copied it, pasted it over itself. I sent that one to the laser and I watched it raster one time and finish. I then thought I'd move the top raster over and down a bit so they overlap about half, and send the job again. It rastered down the first square, to the overlap portion, and on to the botton half of the top square and finished. I thought this process would have done the same as the cutline...repeat twice, but it didn't.

Do I have to send the job to the laser twice to raster twice, or should it work just like the cutline? I don't want to send the job twice since I have other parts of the job that only need to run once.

Any suggestions?

Dee Gallo
11-06-2010, 8:14 PM
Joseph,

I actually like this feature, and use it for doing sections of a document without having to remove/adjust parts I don't want to engrave. I use this all the time because I do many job drawings on one document, make a registration template, then do the engravings individually or in groups according to thickness of the substrate. It saves me a lot of time and effort!

I just make a white box, no outline and cover whatever I don't want to print.

So no, the laser seems to "see" only the top layer for rastering whereas it will "see" all layers for vectoring... which is a pain if you use trace and don't see all the lines in the layers created.

It's not very hard to press go again, though, so without moving the piece you can easily do another run. I do this sometimes when I want a section to be deeper than another section too.

HTH, dee

Scott Shepherd
11-06-2010, 8:24 PM
On rastering, as Dee said, it will only see what's showing, it won't do it twice. You can just select "Copies 2" when you print it, and it'll run the job twice (or however many times you put in).

There is a counter at the top of the driver that shows which run it's on.

Joseph Tovar
11-06-2010, 8:48 PM
Thanks for the lesson...I didn't realize that about the rastering. I thought I was doing something wrong.

I have another question about cutting twice. Would you rather:

-Find the setting of the mid point of cutting through something and cut twice so each time it cust 1/2 way through?

-Use a higher setting to cut through most of it the first time(3/4), and a different(less) setting to cut through the rest(1/4) of it on the second pass?

-Or does it matter?

The reason I'm asking is becuase I'm cutting some 1/4" birch and when I run the second pass it seams to char up a lot more. I haven't tried, but I thought about cutting 3/4 way through the first time and then the last 1/4 through with a less intense setting. I'm not sure if it would help, but I was going to try. The problem with this method is switching settings and not being able to tell the driver to print 2 copies, or just press the "go" button a second time.

Joe Pelonio
11-06-2010, 9:08 PM
It depends on the machine, your power, and the material. If the first pass cuts most of the way through, but maybe you have adhesive on the back,
a faster run with the same power works. If you are doing 1/2" wood on a machine that only does 1/4" then it helps to readjust the focus a little deeper and run again at the same speed and power. You really have to experiment and write it down for the next time.

Mike Null
11-07-2010, 6:31 AM
The answer varies but I generally prefer two passes on wood to reduce charring.

Martin Boekers
11-07-2010, 11:37 AM
try adjusting your frequency, the lower the frequency while still cutting
through seems to save some of the charring.

Make sure you have enough air pressure on your air assist also.


Mary

Martin Boekers
11-07-2010, 11:41 AM
The reason I'm asking is becuase I'm cutting some 1/4" birch and when I run the second pass it seams to char up a lot more. I haven't tried, but I thought about cutting 3/4 way through the first time and then the last 1/4 through with a less intense setting. I'm not sure if it would help, but I was going to try. The problem with this method is switching settings and not being able to tell the driver to print 2 copies, or just press the "go" button a second time.

I don't use it much color matching and multi pages in the document.

I end up sending a new file when adjusting things.

Maybe someone with more experience in color mapping and multi pages can address this.

Mike Lassiter
11-07-2010, 11:57 AM
As to rastering twice - I believe if you copy the objects you want to raster twice then pasted them back you can them change the color of them in Corel Draw that you are mapping in the laser driver say to blue, then assign the same settings you had for the original color you have set to raster to this other color you will be able to raster the same thing twice within the file sent to your laser. If you copy objects and simply paste they will paste exactly in the same location you copied from, so now you have in fact created more objects for the laser driver to process to the laser. It would be helpful to have the second set grouped together so you can deal with them as a group rather than individually.

If you are now rastering with black set to raster, if you copy the same items and color them blue or whatever other color you want then the laser driver will again raster those objects using the color mapped setting you assign for the second color. It is a way to raster (or vector) objects more than once in the same file sent to the laser as long as you set the color mapping right.
I do this for different objects within the file that I want rastered differently from others. The laser will raster one color, then go to the next color. Perhaps you have lettering that you want to stand out more than other objects, this is simply easy way to accomplish it without running the same file again.
I hope I explained it right.;)

Scott Shepherd
11-07-2010, 2:21 PM
Mike, I'm not sure that works when the colors overlap. It works well when they do not. I'll give it a try and report back, but I think I recall reading in the manual last week that it will ignore colors or portions of color that overlap when rastering.

Joseph Tovar
11-07-2010, 7:33 PM
Hi Mike...Good try..After I saw your post, I thought "good idea", why didn't I think of that :).

Anyways, I gave it a try and it didn't work. I do realize what the driver/laser is doing now. For rastering it's only processing what it sees as the top layer. For example, I made a box filled with green and then made a copy and pasted it over itself and made it orange. I sent the job to the laser and made sure both colors were set to raster. The laser complete one pass and finished. :confused:

I then moved the overlapped box down and to the right a little so they would overlap just a bit. I sent the job to the laser and watched. What I saw then was interesting. It began cutting the green the full length..back and forth, but when it got near the bottom where the orange overlapped, is just rastered the "visible" part of the green where it wasn't overlapped. When it finished with the green, it started processing the orange where it was overlapping the green and continued all the way until it was complete. See attachment for clarity.

So it looks like the driver handles the rastering exactly how we also "see" the image on the screen. Good to know. :cool:

Looks like I will do as Dee said and make a seperate page with just the raster portion and send that job again afterwards.

Scott Shepherd
11-07-2010, 7:46 PM
Joseph, here's a shot of the two screens. The one on top is coming out of Corel and the other one is the UCP.

Make it "2" on the copies, then that box that says "0" on the UCP will run it once and then run it again, saying "1" in the box.

Dee Gallo
11-07-2010, 7:57 PM
Looks like I will do as Dee said and make a seperate page with just the raster portion and send that job again afterwards.

Hi Joseph,

I did not say I make a separate page. I would not trust it to line up exactly. I use the SAME page, but block out anything I don't want to print with a white box and run it. Afterwards, I delete the white box.

Alternately, you can save the document, then delete the unwanted parts and print. Then REVERT to saved and you're back. Either way, you are printing the same exact page.

cheers, dee

Joseph Tovar
11-07-2010, 8:42 PM
Hi Dee...I didn't mean to quote you literally, but what I did end up doing was copying the raster portion of my vector/raster image, create a second page, and pasting only the rastered part.

Then I print the first page so it cuts once, rasters once, then send the second page which rasters only to get my desired depth.

Dee Gallo
11-07-2010, 8:54 PM
Hi Dee...I didn't mean to quote you literally, but what I did end up doing was copying the raster portion of my vector/raster image, create a second page, and pasting only the rastered part.

Then I print the first page so it cuts once, rasters once, then send the second page which rasters only to get my desired depth.

So as long as it does what you want it to do, there are obviously several ways to skin a cat, so to speak. It's good to keep thinking and experimenting to push your laser to higher levels. That way, you're not limited by doing things one way only.

Keep it up, dee

Mike Lassiter
11-08-2010, 1:57 AM
Well I feel stupid now. I have done this but not overlapping as has been noted. I didn't realize that mattered although I can understand what you are saying about looking from the top down, as the times I have done it the color change was not done on objects that did overlap.

Sorry for giving wrong information. I THOUGHT I knew what I was talking about.:(

Joseph Tovar
12-08-2010, 1:46 AM
I just found this in a ULS users guide:

Overlapping Fills
If the artwork created has overlapping filled areas, the driver will automatically filter these fills to prevent the overlapped area from being engraved twice. This is similar to color separation in the printing industry. The entire filled area of the object on top will be engraved and only the visible part of the underlying filled area will be engraved. The final result is a what-you-see-is-what-you-get output. This way the color white can be used as an effective drawing tool. Since the laser system will not engrave the color white (this is the background color), it can be used to block out the undesired engraving areas of filled regions and/or bitmaps. However, you cannot use a white fill to cover an outline, the outline will vector cut even though you cannot see it on screen.

Overlapping Outlines
The driver does not filter outlines that overlap each other. If you are placing one outline on top of another, both outlines will be cut by the laser system. This is a useful feature that will allow deeper cutting by passing the laser over a single outline path twice or more. To take advantage of this feature, duplicate the outline on top of itself.

Hidden Vector Lines in Artwork
The driver does not automatically filter out outlines that are overlapped by engraved objects such as fills. If there are filled objects with some hidden outlines underneath, the laser system will engrave the fill and cut the hidden outline on top of the fill. This is a common occurrence when using pre-drawn clipart designed for laser printers. To prevent this from happening, turn on the Clipart Mode feature in the driver. This feature disables the cutting mode and converts all visible outlines to engraved objects and ignores all hidden outlines.