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Rony Nemi
12-02-2009, 8:49 AM
Hi everybody,

I am working with paper with my PLS3.60 and I need that the back of the paper be clean after the cutting. Anybody has an idea of what can I do to get that result? I already clean the cutting table but nothing improve the results, I see in some webpages a cutting table made with nails (or something similar)...any idea?
Thanks!!!

Rony

Niklas Bjornestal
12-02-2009, 9:09 AM
In what way is the paper not clean?
Have you tried to cut the paper without the cutting table?

Jim Sage
12-02-2009, 9:49 AM
What are your settings? You should be cutting paper at a fast speed and very low frequency.

Brian Jacobs
12-02-2009, 10:33 AM
Rony,

One way to do this is to use a 'sacrificial' piece of paper on your cutting table. That way any blowback burns will be limited to the throw-away sheet that is sitting directly on your table.

David Fairfield
12-02-2009, 11:07 AM
I tried the layers, but if the paper is bright white, my experiments tended to be stained with the smoke trapped in between, and its dirty again.

So far, my best result is bringing the power level down to a bare minimum, so that most of the laser energy is expended by the time it breaks through to the other side of the paper. Trial and error process.

You might also get different results with different types of paper. If all else fails, use smoke colored brown paper ;) :)

Dave

Robert Alexander
12-02-2009, 11:21 AM
Hi everybody,

I am working with paper with my PLS3.60 and I need that the back of the paper be clean after the cutting. Anybody has an idea of what can I do to get that result? I already clean the cutting table but nothing improve the results, I see in some webpages a cutting table made with nails (or something similar)...any idea?
Thanks!!!

Rony


Ron I cut alot of paper. the secret to get a good cut without burn marks is this way. For this example I will use a normal sheet of 8 1/2" x 11" paper.
Get some matte board (I get rems from the frame shops in my area) about 2 " wider and taller than the paper you will be cutting by . I will cut out of 3 pieces of matte board a rectangular outline. The pieces will be cut out 8" x 10 1/2". You will also need some small pieces(1" square or less) cut to be used to support the paper being cut.
After cutting take 2 of the matte board pieces, and put it on the laser engraving bed. Put on top of the 2 pieces your paper(do a practice cut first with cheap printer paper first) to be cut, and then put the 3rd paper on top. This will hold down the edges. Paper being lasered will curve up or down. After doing a practice cut, you can place the smaller pieces in areas where your laser is not cutting to support the paper. It is important that you remove the small paper cutouts that will accumulate before they touch the bottom of your paper being cut, because this will result in burn marks.
The settings I use for cutting are 25 speed 15 power and 800 frequency. You want just enough power to cut but no to much that you get soot on your paper.
I just finished cutting some white wedding invites and had no burn marks.

Rony Nemi
12-02-2009, 12:15 PM
Wow!
Few minutes away from the PC and you sent lot of replies! Thank you all guys!

I tried putting paper below of the paper I cut but it doesnīt work, I try to cut over the engraving table, and it doesnīt work too...
I canīt put pieces of material supporting the paper due to the desings I am cutting are lot of circles in a page, so, I have no place without cutting. But the idea is very good to cut large pieces.
Maybe I should try lowering the power...with 50W I am using 100% power, 60% speed, 500ppi. As there is several cuttings I need speed in order to decrease the cost ;)

The other possibility is to ask to my customer to send only BLACK paper as one of you suggests! :D

Thanks!

Rony

Mike Mackenzie
12-02-2009, 12:27 PM
Rony,

You are using too much power. Use 10 power and 10-20 speed PPI 200-300. Note your time running at 60 speed and you will see that even at 20 speed it will be very close to the same times.

The PPI should be low this is what a lot of our customers use when cutting paper.

Rony Nemi
12-02-2009, 12:41 PM
Rony,

You are using too much power. Use 10 power and 10-20 speed PPI 200-300. Note your time running at 60 speed and you will see that even at 20 speed it will be very close to the same times.

The PPI should be low this is what a lot of our customers use when cutting paper.


Hi Mike,

Thank you for your suggestion...I will try, but I am afraid about working time increment.

Rony

Martin Boekers
12-02-2009, 1:02 PM
How many sheets are you cutting at a time and what is the weight of the paper?

Marty

Michael Hunter
12-02-2009, 2:17 PM
I make a jig from 6mm MDF, supported by 2 or 3 strips of MDF to lift it off the cutting table. The jigs have "rulers" on the top to position the paper, and a piece of acrylic goes on top to hold the paper flat. Obviously the jig and the acrylic have holes through, where the paper is to be lasered.
The whole thing bodged together with double sided sticky tape which is durable enough for several long runs.

The gap between the bottom of the paper and the honeycombe cutting table is big enough that there is no flash-back and even smoke from previously cut pieces lying on the table gets pulled out before it spoils the paper being cut.

(I did find that just the jig alone - without supports - was not enough clearance and smoke got onto the back of the papaer).

John Noell
12-02-2009, 2:22 PM
Just to add one more thiing to think about, I have discovered that focus is VERY VERY critical for the paper I cut. Obviously, power, speed, and DPI are critical as well. It took me a lot of experimentation but I now cut heavy paper (for packaging inserts) with absolutely no burn/scorch/flashback issues. My focus guide apparently was off by about 2mm and it took a while to figure that out. Didn't seem to affect anything else nearly as much as paper cutting.

Rony Nemi
12-02-2009, 2:25 PM
How many sheets are you cutting at a time and what is the weight of the paper?

Marty

I am cutting one by one, and it is very light paper till 200g paper.

Rony

Andrea Weissenseel
12-02-2009, 3:33 PM
Rony, it would help to know what kind of laser you are working with, otherwise recommended setting won't help you (lol hope I didn't overread it:D)

I'm cutting a lot of paper, most of it bright white chromolux - and for testing purposes I mostly use normale copy paper. I cut it on the honeycomb and the paper always stays clean. You only get those burn marks, as mentioned before, if you use too much power or going to slow

Rony Nemi
12-02-2009, 4:36 PM
Rony, it would help to know what kind of laser you are working with, otherwise recommended setting won't help you (lol hope I didn't overread it:D)

I'm cutting a lot of paper, most of it bright white chromolux - and for testing purposes I mostly use normale copy paper. I cut it on the honeycomb and the paper always stays clean. You only get those burn marks, as mentioned before, if you use too much power or going to slow

Hi Andrea,

Thanks for your comments! I am using a 50W Universal PLS3.60. Apparently I should decreasy power and speed. I will try it soon and let you know the results...:)

I am really surprised about so much people helping!!! :) - Thanks all!!!

Rony

carl stevenson
12-03-2009, 5:02 AM
I cut a lot of paper.

The type of paper you use is critical as well. Cheap printer paper actually works quite well because it is thin and can be cut quickly on low power and maximum speed (40w rabbit 3040)

The worst paper is cartridge paper or paper/card with rough surface. The paper cuts well and looks clean, but the edges always seem to have soot on them when I run my finger along the edge.

Coloured paper with a lot of dye in seem to work well (deep blues and reds)

White paper and card is fine as long as you find the right combination of paper and have perfect focus on the beam.
I always cut everything at the lowest possible power (10 percent on my machine) and adjust the speed to suit the thickness of the product.

Paper is made from many different materials including wood fibre, cotton fibre, grass fibre, polymer fibre, chalk, clay (for coated papers) etc, so you will need to experiment on as many as possible.

les grayson
12-03-2009, 5:04 PM
Hi rony
I cut a lot of paper and was getting the same problem .I made a raised table using 12mm acrylic and lasered a grid of holes 20mm apart over the acrylic the holes were the size of a pop rivet (the thick end into the acrylic). Glue thin acrylic at the corner ( top left) to form a right angle and a stright edge along the top edge, so you can register the paper.

Michael Kowalczyk
12-03-2009, 7:19 PM
Hey Les,
Sounds cool show us a pic if you don't mind.

Rony,
When I cut paper, which is rarely, I do 4 sheets at a time of colored construction paper and keep the top 3. Settings are important. I use a Trotec so my settings are different than yours.

Rony Nemi
12-09-2009, 12:10 PM
Finally, the best results that I obtain came from lower the laser power (more than I thought). It was simple but I take note of several ideas you sent.
Thanks!!!

Rony