Alignment -- cutting printed paper

[David Fairfield]

Hi Everyone

I need some advice on aligning material in the laser.

Have a job where I'm cutting out paper parts off 8.5"x11" pre-printed cardstock. I'm using the same .ai file that the graphic artist used, so the vector outlines themselves are exact.

The trouble is lining up the paper in the laser, so that the cuts are exactly aligned with the printed images. If its off by even a fraction of a mm, I get ugly white borders on some edges of the completed parts.

It turns out to be trickier than I thought. Is there some "easy" way to use the red dot thing, or cut a jig, to line up everything tightly?

Looking forward to hearing your ideas, you guys always amaze me!
Thanks!!

Dave

[Gary Hair]

A couple of things come to mind.

First, create a fixture to hold the paper, that way you don't have to worry about the red dot/laser beam alignment. Second, create your printed images with a bit of bleed around them so you won't have any possibility for gaps. Alignment within a fixture should eliminate the need for the second suggestion but it won't hurt to do both.

Gary

[Scott Shepherd]

Thinking along the same lines as Gary, I'd do a fixture as well. Probably out of clear acrylic, vector out all the things where the cutting will take place, raster a couple of registration marks on it, and you can lay it on top of the paper to make sure it's lined up right, and the fixture is up against the rulers.

[Doug Griffith]

Another technique I use:
1) take a piece of thin acrylic/card stock you have laying around and cut a rectangular hole in it that is larger than the paper. (ie. 9 x 11.5)
2) tape a piece of acetate the same size only along the right hand edge.
3) wedge the whole thing in the up left corner of the laser.
4) laser lightly onto the acetate just enough to use for registration.
5) insert paper and align. Cut holes in acetate to aid in alignment if needed.
6) flip acetate over to right when lasering the paper.

Cheers

If you use Scott's method, it is more accurate to reverse engrave the clear acrylic so the thickness of it isn't a variable when looking through it.

[Kim Vellore]

Dave,
I did that once for my kids school decorations with card stock and I used small circle at 4 corners printed them on the card and laser cut them so you get them aligned in you drawings between the ink and laser printer, it was going fine than it was off after some time, I finally realized the card stock does slip some times in the ink printer and the print could be off by a mm giving it a white border. If you get your printer to print all the paper dead on that will be a first start. You can stack up all the papers and look it up in bright light to make sure. Once you get that going you can try the other alignment tricks recommended by the good folks here.

If your drawings are colored I would recommend overflowing the color a little beyond the lines to be cut.

Kim

[Robert Ray]

I do this all the time, because I print sheets of decals, then use the laser to precut through the decals film around the lettering.

What I do is draw a line across the topmost printable area and leftmost printable area, an X and Y line, and group it to my decal artwork.

Then when I print out the decal sheet it has the X Y line, and I cut along those lines with my paper cutter.

Next I ungroup the artwork from the XY line, and cut/paste it to a new page, leaving the XY line on the top page.

Print the XY line to your laser and cut through a piece of chipboard that you butted up against your rulers on the laser, and now you have an alignment template.

Then send page 2's print job to the laser, and butt the decal sheet up against the template.

See these pics:

http://www.trainboard.com/railimages/data/687/00013.JPG

http://www.trainboard.com/railimages/data/687/00120.JPG

http://www.trainboard.com/railimages/data/687/00223.JPG

http://www.trainboard.com/railimages/data/687/00423.JPG

-Robert ray

[Rodne Gold]

We take a peice of pex and cut it 100% square
We print on the paper with 2 registration marks with cross hairs , we send the reg marks to the laser and instead of lasering em , make 2 teeny holes in which we place small pinheads.

The problem mostly is that the printer and laser are "out of scale" , Ie the printers XY is not the same as the lasers , however you can compensate for this in software and make 100% sure that both reg marks end up in identical position. In other words , use corel to either compress or expand the graphic by some factor (can be in both X and Y directions) so that printed and lasered reg matks line up perfectly, use this factor ALWAYS when importing a printed graphic that is to be cut to the laser. This only has to be done once.

So now the pex has 2 pins sticking up a little bit (we cut em short) where the printed reg marks are.
All you need to do for perfect registration time after time is to put the centre of the crosshairs atop the pin and push down. Then just cut the outlines , the paper wont shift at all
You can also put a piece of sacrificial thin cardboard under the paper if you not kiss cutting and are die cutting right thru so there are no issues with the pex template
Obviously the printed reg marks must always be in the same position for you to use the jig for all your die cutting and the laser must always start from home or some other pre defined position when using it.

[David Fairfield]

Hi Everyone

Just wanted to get back and say all the ingenius ideas are much appreciated. I think I have the problem worked out, thanks to you!

Dave