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Scott Woodson
02-22-2011, 7:04 AM
I've purchased 1/8 baltic birch plywood now from three separate vendors. Although the price has swung dramatically (from $11 a sheet to $28 a sheet) I've noticed an increasing problem getting a good cut with my 45 watt epilog. There seems to be more glue (probably filling voids in the inner core) that chars and doesn't cut through. You can even see the laser turn colors when it hits this material. Is anyone else out there noticing this? I'm trying to compensate for this by slowing the speed of the cut (using 25 spd, 100 pwr at this point) but am now noticing more burning and of course it is costing me time. I've checked to see if my tube is losing power (cuts through 1/8 arcylic with factory recommended settings) so I don't think the tube is losing power. I've also fooled around with the HZ setting, but still can't find a sweet spot (moved from 500Hz to 2500Hz). Looking to see if it's the supply chain up here or if this is a universal problem with others.
Thanks in advance.

Scott

Steve Clarkson
02-22-2011, 7:27 AM
I'm wondering if you're on to something............two years ago, I could cut 1/8" baltic birch at 100P/35S.........and for the past few months, I had to drop it to 100P/27S to get the pieces to completely cut through..........I too was thinking that my tube was going.........

Chris DeGerolamo
02-22-2011, 8:58 AM
Scott, from my experience, slowing the laser down does not solve the issue. As you found, you get more charring and the glued areas may or may not get cut. Depending on your application, I would recommend scoring the wood with a exacto knife or similar once it is done to remove it. You should be able to pick out the problem areas by visual cue alone. Try this too: spray the board with Pledge. Do some tests and see if it works for you. I have found that it helps a bit, I am unsure why. Good luck.

Larry Bratton
02-22-2011, 10:02 AM
Plywood never does cut as well for me as solid wood. I know for sure my tube is not going because I can cut 1/8" acrylic with 10s/45p/500f and get a clean cut. (The manual recommends 15s/100p/5000f) I cut some 1/8" baltic birch plywood last week at 30s/100p/500f. It took 2 passes to get through it. However, the cut was clean with little charring. I surmise the reason is the different glues and I there is probably no way to standardize the veneer layers.

Michael Kowalczyk
02-22-2011, 12:42 PM
Hey Scott and others,
The 3mm (1/8') Genuine Baltic Birch plywood we use cuts fine on our Trotec and I have actually been able to increase the cutting speed by tweaking the settings a little. So my settings are 100% power 1.15% speed and 5000 Hz. The pics shows the edge quality.

Make sure you are getting Genuine Baltic Birch plywood by checking the stamp in the corner.

Michael Hunter
02-22-2011, 8:03 PM
And check that it is interior grade too - the WBP waterproof stuff has the laser-proof glue.

Darryl Jacobs
02-23-2011, 12:20 PM
I too have seen vast differences between grades of Baltic birch lately and I have found a bit better results with playing around with the frequency and speed. Too slow and hot and it chars and then the problems start.

I have also had some 1/16" that cuts worse then some of the 1/8th that I use. I used to like working with the stuff, but I just hate it now to get decent cuts.

Scott Woodson
02-23-2011, 6:56 PM
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.

Mike Null
02-24-2011, 5:16 AM
It is very important to check flatness when cutting plywood. It is quickly affected by humidity changes and can result in areas being out of focus with your laser.

Richard Rumancik
02-24-2011, 9:37 AM
The problem with cheaper plywood is that it may be Chinese plywood, not Russian birch or Baltic birch. Apparently the quality is much poorer. You may find internal voids, and there may be excess glue inside. Also some of it uses non-birch softwoods for inside the inside ply layers. Let us know how you make out with it, but perhaps it is better to pay more and get something that works reliably. A place that supplies cabinet shops would have a more consistent supplier. The big-box stores will buy the cheapest and change suppliers based on price. Plywood is plywood, right?

Even the best plywood will have some internal knots however and the laser can have trouble cutting through these.

Kay Bengtson
02-24-2011, 11:26 AM
I cut 1/16" Baltic/Russian birch ply regularly and I also have found that it varies more than I would like. Some sheets cut like butter but others take two passes or end up being a total loss. Sometimes, the thickness varies and they have much more knotty areas on one side which causes the laser not to cut through. If it chars at all, additional passes just won't work. It seems that quality control is slipping in just about every product nowadays.

Kay

Scott Woodson
02-24-2011, 7:45 PM
Kay, I would agree. I've purchased 1/8 from three separate vendors with 3 separate price points, but recently not matter where I get it I've encountered this problem. It was intermittent at the beginning, but now all the sheet exhibit the same problems. I was told the 5X5 sheets are the standard Russian Baltic Birch, the Chinese products were normally coming in 4X8 size. All the plywood I've purchased is from hardwood suppliers to cabinet shops vice big box home improvement stores (who for the most part won't sell less than a skid).

Bill Cunningham
02-24-2011, 9:44 PM
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...

George Brown
03-17-2011, 10:20 PM
I bought some Baltic birch 5x5 sheets, and have the same problem. Most of it cuts easily, and then it hits areas what WILL NOT cut, no matter how much power is used. A cut through that area with a saw revealed a different appearance of wood, maybe a void filled with a biscuit of some sorts. I may try some Finnish birch, maybe it will be better?

Ron Chapellaz
03-19-2011, 12:26 AM
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. I finished off the last batch of wood I had in stock and I just picked up 5 more sheets. I'll be cutting again next week. It will be interesting to see if I'll be able to cut at the same settings. I'll post my findings to the forum. I wonder if humidity might play a factor in the ability of the laser to cut through. Could the energy of the beam become absorbed by the moisture in the wood? Maybe others can chime in with their expertise...

Frank Corker
03-19-2011, 6:01 AM
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
03-20-2011, 1:57 PM
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
03-20-2011, 2:34 PM
[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
03-20-2011, 7:37 PM
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
03-20-2011, 9:06 PM
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
03-20-2011, 11:06 PM
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
04-23-2011, 9:02 AM
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
04-23-2011, 10:22 AM
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
04-23-2011, 8:02 PM
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
04-23-2011, 9:31 PM
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
04-24-2011, 1:10 PM
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
04-24-2011, 6:41 PM
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
05-13-2011, 12:41 PM
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
05-13-2011, 2:35 PM
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
05-13-2011, 10:06 PM
My 80 watt can cut through 1/8" BB in one pass at 100 power and 20 speed. What wattage is your Laser?

Scott Woodson
07-17-2011, 7:54 AM
UPDATE on this topic. I'm probably obsessed to the point of nauseating, but still bugging me. I've talked to a couple of suppliers I deal with and was told due to environmental issues as of 1 January the old glue that was used in the manufacture of plywood was banned (both for domestic production and import products). The new formula of the glue does interact with the laser (trying to get someone to give me some of the glue so I can send to Epilog to see why it interacts). I was told that those of you that aren't experiencing these affects may be still getting stock manufactured prior to Jan. To my dismay I was told this was an industry wide change and when the "old glue stock" is gone that's it. I'm using BB/BB and I think what I'm experiencing is the glue puddling in voids in the inner core and that's what's creating the problem. I've slowed down to 19 speed 100 power and am able to get through 95% of my workload (considerably less than the 35 speed I used to be able to run with my 45 watter). Best of luck to all...and I guess I'll now let it go :-)

Dan Hintz
07-17-2011, 7:18 PM
Spending a bit more for quality ply is well worth the extra pennies to avoid dealing with random settings and failed projects.

Craig Matheny
07-17-2011, 9:11 PM
Spending a bit more for quality ply is well worth the extra pennies to avoid dealing with random settings and failed projects.

You are correct Dan however when you deal with Baltic Birch or 1/8" ply you are limited. I do not buy this glue story because I buy this stuff by the pallets and my supplier deals with over 70 plants over the last year my product has not changed other then the fact of quality control bad wood in the center ever see dark brown Baltic Birch? No me either but it was in one lift I got any my yard replaced the complete lift. I cut this stuff 7 days a week 12 hours a day and go through 130 - 5 x 5 sheets a month. Just took my sheets to Epilog and ran on their new 50 watt at 100 pwr 35 sp 500 freq cut nice lift the board pieces fall out. My 45 watt will only cut at 16 sp 100 pwr 500 freq. The thickness fluctuates drastically it is called the gosh (spelling) system 3mm Baltic Birch can be .11 - .14 measure your wood cut a notch in a scrape wood .122 and see if your wood fits. Moisture has not been an issue the yard cuts my wood to 12 x 24 wraps in plastic i pick it up and put it in my outside storage no insulation and cuts normal rain or shine. All I know is I want a 35 watt machine that cuts 1/8" Baltic Birch at 100% speed I could make a fortune and not have to by a second machine. Would love to get a sample file to run and do a comparison.

Ron Chapellaz
07-18-2011, 1:52 PM
Craig, with the last batch of 1/8" ply that I received I am now cutting at 85 speed 100 power. Hearing that everyone else is cutting slower than I am makes me wonder if my zing at 100 speed might be only as fast as yours at say 50 or maybe 25 speed. I've never paid close enough atttention when seeing other machines at the trade shows. Maybe someone from Epilog or other members here could inform us as to the speeds and if they vary from model to model. After all these are just numbers assigned to the overall speed of the machine. Maybe we should all test the various machines by vector cuting 1/8" ply to cut through at a single pass over a 12" distance and see how long it takes.

Craig Matheny
07-18-2011, 6:22 PM
Craig, with the last batch of 1/8" ply that I received I am now cutting at 85 speed 100 power. Hearing that everyone else is cutting slower than I am makes me wonder if my zing at 100 speed might be only as fast as yours at say 50 or maybe 25 speed. I've never paid close enough atttention when seeing other machines at the trade shows. Maybe someone from Epilog or other members here could inform us as to the speeds and if they vary from model to model. After all these are just numbers assigned to the overall speed of the machine. Maybe we should all test the various machines by vector cuting 1/8" ply to cut through at a single pass over a 12" distance and see how long it takes. That is a great Idea I have created a file for us all to use and see how long it takes to run it. I will post my findings soon. Post all 3 settings pwr/sp/freq and time it takes to run.202281

Craig Matheny
07-18-2011, 6:46 PM
I have posted this as a new topic was not sure how to remove this or point to the new one it is called Time Trials I will post my speeds there

Ian Franks
07-20-2011, 2:55 PM
Even down here in SA I am having problems. I got some samples from a board supplier of 4mm pine ply and could cut it. Then went and had a 1/3 rd of of sheet cut for me and it won't cut through just chars. Also tried 3mm red oak ply and that works if we cut 100mm strips as it warped badly. I will try and find out if the glue has changed.

Adrian Hill
07-20-2011, 5:31 PM
Ian, if you cut MDF you must make sure you get imported MDF. The local stuff made by PG Bison (a dark brown/grey colour - it also looks as if it is made from a coarse material) does not cut. At full power on my 70w it just chars without cutting through. I don't have the problem with the imported reddish brown MDF though.