1/4" Birch Plywood PROBLEMS

[Mark Maslonkowski]

I will start out bu saying i have reviewed seveal post on this and none have helped to date. Ok so I have a 60 watt epilog helix that was new June of 2012 every time I try to cut 1/4" anything all I end up with is a charred edge and can never make it through in one pass. I am using air assist and have tried a multitude of different setting. My most recent attempt is with 1/4" birch ply. I have checked algnment it good. Can anyone help me out.

I will post pictures when I get into the shop in the morning.

Thanks
Mark

[walter hofmann]

Hi mark
check your max focal point and this distance on all four corners.
to check the focal point put a strip on the table and on the right side a piece under about 1/2 inch then cut just a line with 30% power then measure the distance between the laser head and the material surface where the line is the thinnest thats your max focal point. take this measurment to all four corner of your table and make sure its the same everywhere.
greetings
walt

[Mike Null]

Mark

It's possible that your settings need some adjustment. If you'll post them somebody who has a similar machine can offer an opinion.

[Larry Robinson]

Are you cutting Baltic Birch or just Birch Plywood?

[David Fairfield]

Plywood can be tricky, depending I think on the glue used to bond it, or some mysterious factor. So its not really a good material to test your laser. You don't know if the laser is the problem or the wood. Are you using an appropriate lens for deep cutting? If your alignment is checked out, then recheck the focus. Your autofocus or manual gauge may be off. There's a diagnostic for checking focus, but you can do it by trial and error on some scrap. HTH Dave

[Pete and Carmen Vaca]

I can cut 3/4" ply ...... But I also had this problem, turns out it was the Home Depot 1/4" ply intended for subflooring (think bathrooms) it was VERY troublesome, I figured out that the glue and fillers were melting and puddling, then the air assist was cooling it off and re-gluing it.

[Michael Kowalczyk]

Exterior glue (what you mostly get at big box stores) is a problem but I would first look at your mirrors, all of them and make sure they are clean and aligned properly. We cut our 6mm Genuine Baltic Birch without char all the time. Once in a while you may get a pin knot in the core that may char but with clean mirrors and properly aligned mirrors and focus through out the table you should have no problems cutting 6mm (1/4") with a 60 watt. We use 100 % power with .51 % speed and 5000 htz. Since is it a Trotec our settings will be different.

[Mark Maslonkowski]

It took a da o get to the shop again but here are some photos. The first one is of the edge and the second is my finger after running it over the charred edge I am using a 60 watt epilog helix with the following settings the only settings I could find that would cut through. Speed 10 power 100 freq. 300. I am sing a big box 1/4inch birch ply. I can't seem to burn through 1/4" MDF. Either. Any and all help would be appreciated. If som out there happens to have the same engraver and has some settings to try that would be great

[Larry Robinson]

Get Baltic Birch Plywood. Full size sheets are 60 " X 60". The key word is BALTIC. Never found any at the big box stores. I know you can find it at Rockler in precut smaller sizes. I think also some of the hobby stores also carry it in smaller precut sizes as well. I have cut the big Box birch and have had the same results as you with the black soot when using an 80 watt laser.

[Michael Kowalczyk]

Mark please click on this link and then click on the picture. If you can zoom in, you will see what Genuine B/BB Baltic Birch with interior glue looks like.
http://www.sawmillcreek.org/showthread.php?195449-FreeStuff-Winners-Russian-Birch-Ply-amp-Premium-MDF-Sheets&p=2017422#post2017422

Also please show us what the core of your material looks like before you laser cut it. Charring like that may also be an issue with the core not being solid veneer.

[Bill Cunningham]

You can also drop your freq to 150.. Higher freqs charge the wood..