1/8" plywood problems

[Frank Corker]

For cutting wood, the frequency seems to be the main cause of cutting, if it is not selected correctly you will just end up with charring or no penetration through the wood.

[Craig Matheny]

Thanks all for your input. I was beginning to think it was me only. I did check the plywood and it was a green mark in the corner indicating B/B. I think I'm going to continue to play with my frequency and speed settings to see if I can get acceptable results. I've found a source for $11 a sheet so at least this will lower my costs some and make up for the slower production.

Scott there is more then the BB on the green stamp what are the last two letters BB or CP? I buy BB/BB for 8.70 a sheeet here in So Cal. was using a supplier that was buying BB/CP and sorting out the good wood selling it as BB/BB but the core is still the CP so don't buy anything less then BB/BB.

However with that said I to have noticed a slow down over time with the cutting of the wood and I I have had a new tube installed and lens still slow the other day took the upper mirror off the arm and notice slight scratches how they got there no clue.

Good luck

[Craig Matheny]

[QUOTE=Ron Chapellaz;1663773]I just finished cutting 1/8" Baltic Birch last week and managed to tweek my settings for the better. I used to cut at 70 speed 70 power and now I am cutting at 100 speed, 100 power, and cut through on one pass with my 35 watt. QUOTE]
What did you tweak in your settings? and are you cutting straight lines or what?

[Ron Chapellaz]

Craig, I am cutting straight lines, curves, whatever. I originally was following the recommended settings and not always was I able to cut through on one pass. Then just playing around with settings I found I was able to run it at 100S 100P with the freq. at 500. I tried lowering the power and changing the freq. but then I was not getting through on the first pass. I'm not exactly sure why Epilog has the settings for 1/8" at 70S 40P and 500 freq for the zing. In my opinion, everyone should try and get their machine speed as high as possible to be the most efficient, as long as you can do it in one pass. If you can dial in just the right amount of power then you won't char the edges as badly.

[Don Williams Michigan]

I have an Epilog 45 watt and from the first day I owned the machine cannot vector cut 1/8 plywood (any grade) at a speed higher than 15? I have tried many different things, but cannot get good cut through unless set at 100 power and 15 speed.

Do I have a bad tube?

[Ron Chapellaz]

Are you able to cut faster through a straight line. I had once vector cut an item that had a lot of nodes after I had done a trace of it and the laser took forever to cut, but that was due to a high node count. Maybe that is the problem that you guys are facing?

[Scott Woodson]

If your using a Epilog, Drop your frequency to 150..
I cut 1/8 @ 100power/10-15speed and 150 freq., and get a clean cut with no char.. 500 is high, 5000 is 'way' to high. Forget the book...

Bill, thanks I finallly got to try these settings and although it's taking a little longer to cut I'm not wasting my time poking and exacto knifing the pieces out. I still see where the laser beam changes colors when it hits the glue (greenish hue), but for the most part it is cutting through. Appreciate the tip, thanks all for helping.

[shawn zumbrum]

Ron
Moisture is the key i bought a moisture meter just to find out 2 to 3 percent more moisture and it takes all the laser has and does not cut worth dirt. moved my wood to a different are in shop I left it sit two days and cuts great know.

[shawn zumbrum]

scott
i have found that if the wood has alittle moisture in it it will not cut good it only takes 2 or 3 percent to make a big deal. i bought a moisture meter for this and was quite surprised at that but i put the wood at a different places in the shop and two days later the same wood 2 percent less moisture cut great.

[Bill Cunningham]

Definitely! The dryer the wood the better/faster it cuts. I have some poplar I salvaged from old chest of drawers. This stuff is dryyyy, .375" thick, and cuts like butter with only a light brown edge at the same speed/freq/pwr as I use for 3mm BB.

[Scott Woodson]

scott
i have found that if the wood has alittle moisture in it it will not cut good it only takes 2 or 3 percent to make a big deal. i bought a moisture meter for this and was quite surprised at that but i put the wood at a different places in the shop and two days later the same wood 2 percent less moisture cut great.

Shawn,

Don't believe it's moisture as the cut is very good until I hit certain spots in the wood. The laser beam at the contact point will turn from red to green and a black puff of smoke will come out, that's why I believe it's glue or something in the second layer. If it was just wood I'm not sure the beam would change color. I am begining to think what is happening is the heat from the laser is partiallly melting the glue and absorbing the laser energy because when you look on the back side it's a clean cut until I get to the point of the "green" and the cut doesn't make it through the second layer. When I go to score the other side with the exacto knife I can't even cut through it with the exacto knife, so I think the glue is some type of polymer that is reacting with the laser. Don't think it's my tube or anything else with my set-up because I'm still able to cut 1/8 acrylic with factory settings and a great cut. Epilog tech support told me that if I can cut other materials at factory recommended settings my tube is fine. The grade markings on the plywood are BB/BB 13-4 INT.

[Michael Kowalczyk]

Scott,
What you are probably experiencing is not glue induced but more likely the core having small tight knots and mineral streaks. Unless you get the Finnish ply (B/B) that is from hobby shops and usually $4-5.00 per sqft and up, there will be small knots or footballs that will effect your laser cut. Using a BB/BB ply has a % of footballs and or mineral streaks on the outer layers so you can be sure they are in the interior also.

[Mike vonBuelow]

From Signwarehouse techs re Mercury models:


You are never going to get rid of the char on plywood. The glue/adhesive that holds the pieces of wood is usually what is causing
the char to occur. Unless you can find a plywood that doesn't have the glue/adhesive then you are always going to get this really bad char.

What people are taking about the htz is the PPI setting in the driver. If you have a M Series 1, it is located on the options tab inside the
driver. If you have an M Series 2, it will be located on the Pen tab inside the driver.

P.P.I. stands for pulse per inch. This only affects Vector cutting. By changing the amount of times the laser pulsates per inch, the
distribution of energy is changed. The range is 30 to 1500 PPI or you can choose auto mode (the X). When choosing auto mode, the system will
assign the proper PPI value automatically corresponding with the DPI.

[Jonathan Overlin]

My issue with 1/8" birch (from my local big box lumberyard), is that is will cut 85% through on the first pass, 95% on the second, 99% on the third. So when you flip the piece over, you will see some areas that will drop through, but some areas will have a sort of 'perforated' cut line (that always rips whe you force the pice out). Very frustrating

[Larry Robinson]

My 80 watt can cut through 1/8" BB in one pass at 100 power and 20 speed. What wattage is your Laser?