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Jason Saul
11-17-2010, 11:20 AM
Hi all - Been lurking/reading/learning for a while and recently purchased an Epilog Helix 30w which I've been having a ton of fun with :]

Tried to search the forum for info about cutting through multiple sheets of paper and/or cardstock but couldn't find much - Anyone have experience with hitting 2 or more sheets at once to cut out some basic shapes? If so I'd like to hear tips and tricks regarding how to get clean cuts and just how many sheets people have been able to do - or can you really only do 1 sheet at a time successfully?

Thanks in advance! Oh and a special shout-out to Dee who helped me with some exhaust issues - MUCH appreciated! It's been smooth sailing so far :cool:

Dan Hintz
11-17-2010, 1:37 PM
For one thing, you won't be able to rely on the exhaust to vacuum seal anything but the bottom sheet to the vector table. You may (or may no) need to separate multiple sheets with sacrificial sheets, like wax paper, and the lower on the stack a sheet is the heavier the abuse it will take. I've successfully done two sheets without a problem, three in a pinch, but after that it's dicey, at best.

Chris Mahoney
11-17-2010, 2:43 PM
I wouldn't recommend cutting multiple sheets of paper at a time. First time I tried it I had to get the fire extinguisher :eek:

Jason Saul
11-17-2010, 2:47 PM
dang. ok. thanks to you both for the advice! have a good one.

Joe Pelonio
11-17-2010, 2:51 PM
I have done it with cardstock and construction paper, as Chris said thinner paper will catch fire. For what I do I make a 1/16" or 1/8" acrylic
template in the shape of what I am cutting. That keeps the outside waste material from flying about, and helps keep the cut pieces in place
as it goes to the next place to cut. You do have to stand and watch it the whole time and be ready to lift the lid, with a water mister in hand
in case a piece does fly up and catch fire, but I have been able to do as many as 6 construction paper at a time and make several hundred shapes with only one or two panic stops using this method.

David Fairfield
11-17-2010, 5:47 PM
tends to trap smoke in the interior layers, not good for light colors.

Jason Saul
11-17-2010, 5:49 PM
joe - thanks for the tips; much appreciated!

david - good to know. we are probably going to use black cardstock so perhaps it will work out.

cheers!

Duane Parcells
11-19-2010, 10:32 AM
Cut it all the time. My 75 watt uses 20s, 20p, 500freq. I load about 25 sheets of paper or 15 sheets of cardstock so it doesn't cut all the way through.
I use coins to hold down the pieces so they don't fly in to the laser beam from the air flow. If you have enough weight you don't get the charring with the exception of the top piece. You can lower the frequency and make perforated cuts too.

Jason Saul
11-19-2010, 10:35 AM
AWESOME to hear - thanks Duane! appreciate you posting your settings, too!

Viktor Voroncov
11-22-2010, 9:16 AM
We just finish one project - laser cutting up to 25 sheets of 120 grms/sq.m paper with adding inert gase. Very good result, no yellowing/burning at all. We have used argone as it was availbale for tests in small volumes (just 4 liters). For commercial use customer have purchased compressed CO2.

Martin Boekers
11-22-2010, 9:52 AM
you may want to make a frame it hold the paper in place.

If you have a steel table then magnets should do.


Marty

Jason Saul
11-22-2010, 10:44 AM
hi Viktor - thanks for the suggestion - though I'm not sure what you mean by using 'inert gase' or argone to assist with cutting the paper - could you elaborate a bit?

Martin - thanks, good idea - not sure if my table is steel but i believe it might be! will try it out - thanks again everyone!!

Jorge Pease
03-21-2011, 2:51 PM
Im interested in knowing more about using the gasses to prevent flaming yellowing or burning as well. If the paper is clamped in a jig, wouldn't it be just like cutting wood? How fast can you cut through 1/4 in wood?

Dan Hintz
03-21-2011, 3:01 PM
How fast can you cut through 1/4 in wood?
How powerful of a laser do you have? Is it plywood? What's the quality of the glue used to laminate it?

Jorge Pease
03-21-2011, 3:11 PM
I have not purchased the laser yet, trying to determine the power we need. We want to cut through up to a 1/4 in stack of paper. I see that a couple of people had success cutting stacks of paper on this thread. I am trying to gauge the speed of cutting through multiple sheets of paper (clamped together) therefore the wood question. We are thinking a laser of around 100W +-

Richard Rumancik
03-21-2011, 3:19 PM
I can't comment on the power you need, but just the process. What kind of a product are you making? If you clamp large sheets around the outside it doesn't necessarily mean they will be in contact everywhere. Gaps between pages will result in smoke/char getting between. Also when the sheets are handled that char may smear around. They will also smell like burnt wood. So what you are making may affect whether stacking will actually work.

Jorge Pease
03-21-2011, 4:12 PM
The product is small 3 in x 3 in stacks of paper glued on one end like sticky notes. Normally you would diecut them but in this case there are too many shape possibilities. I was thinking we could cut a zero clearance plate out of wood and use that to clamp the paper down. We are just cutting a silouhette. I asked about charring and was told the edges could be black but excessive burning or smearing wouldnt be good. I have read here and somewhere else that using gasses to prevent flaming works well but I think I would still clamp along the entire edge.

However, even if we can work that issue out, i am wondering about speed

Richard Rumancik
03-21-2011, 8:03 PM
Jorge, from what I have seen, if you do manage to cut it, you will get black soot all over your hands as soon as you pick up the stack.

The Handbook of Laser Material Processing says this: "The generation of carbon dust cannot be avoided in carbon-based materials, and so the cut edge will be covered in a thin layer of carbon dust. The majority of this can be wiped off, but the cut edge is invariably darkened."

In this case, if you try to wipe it, it will just smear on the layers and probably get between.

For wood, cardboard, plywood, and paper they suggest air as the assist gas. If you starve it of air, you probably won't get a good cut, as the mechanism of the cut is chemical degradation (aka burning).

I cut corrugated fibreboard and my hands get dirty as soon as I pick up a piece.

Sorry that is probably not what you wanted to hear . . .

Jorge Pease
03-21-2011, 9:58 PM
Ok, thanks. Maybe we should be looking at clicker type dies, hate the thought of thousands of those dies hanging around. I will continue to investigate. Have a good night.

Jiten Patel
03-22-2011, 5:36 AM
Jorge,

Black soot is GOING to happen. We cut paper/card for a business and use soft (make-up) brushes to brush the soot off the cardstock. It comes off nice and clean. It's a bit labour intensive, but out products command their pricetag.

With regards to stacking, I still cannot figure out a way in which I get the quality to match that of a single sheet being cut. Just cannot get the yellowing/staining to go. One sheet at a time for us. Stacking would be the holygrail for my business. It would save me hours and hours. But saying that, an autofeeder would be nice if 1 at the time is all we can do.

Jorge Pease
03-22-2011, 4:59 PM
Thanks Jiten,

Iv been told the edge of the paper itself being darkened might be acceptable so I guess its still a possibility we may do the laser route. Has anyone cut paper that has been uv or aqueos coated, that should eliminate any smudging on the face of the paper, no?.

Im checking out machines now, maybe I will ask if a supplier can demo cutting a stack using a little inert gas with a stack of paper that is clamped down on the keeper side of the cut.

Also checking into cost for cookie cutter like clicker dies. It might be possible but would be thousands of dollars that i'd rather get and put into a machine.

Jiten Patel
03-23-2011, 5:52 AM
We looked into dies, but the detail we do, its wouldnt be possible.

Check out our website (on my profile) and have a look at our products. there are some close up shots of the edges, which might give you an idea of what the finished edge looks like.

Jorge Pease
03-23-2011, 7:56 AM
Checked it out, very nice! Our immediate need is much less intricate. I can see how a die would not work for you. I liked the edges, didn't look burned at all but I guess with multiple layers that changes the game entirely.

I am looking at cnc steel rule benders and making clicker type dies in-house, we only need simple profiles. Still want to add a laser to our shop though, maybe a small one.

Rodne Gold
03-23-2011, 8:31 AM
Jiten, I'm sure you could make a simple shuttle type system without a lot of hassles by using a sliding jig or just have a few jigs you can easily take in and out ,ie one jig in, cut , take it out ,put next one in , reload old jig etc.
The probem I see with an autofeeder in your application is dealing with the bits you cutting out. If I were making an autofeed , I would most likely use a printer and just output a blank page into a modified output tray (like a honeycomb instead of the printers output tray) , perhaps a tipping system of some sort to dump the cut sheet and the cuttings into a holding bin after cutting would work to leave a clean cutting surface for the next sheet. You would most likely have to run your laser open to do this.

Jiten Patel
03-23-2011, 1:03 PM
Rodne,

Thank you for that, our laser is open as is.

I like the idea of the slider, that might work, still manual, but might be quicker than the current process. Building a full automated system would require way more knowledge and skill than I have at the moment. I'm more of a designer than an engineer.

But some great ideas for me to think about.

jorge, not sure about steel dies, didnt really go into depth with them as we ruled them our real early in our business.