Issues Cutting 1/4 Plywood with 60watt

Hey All!

A little info on my laser. Its a 60watt Chinese laser, RUIDA RDC6442G controller, chiller that keeps temp at 68 degrees, upgraded air assist to run at about 10-15 psi. Also has good venting with a blower.

I installed a Milliamp Gauge, and my tube threshold is 18 which the gauge shows it hits at the 43% power mark. Mirrors are all cleaned and seem to be aligned when I did a most recent test. Lens I have used an the stock one that came with it and also just added a fresh new 2 inch lens.

The laser has always struggled to cut 1/4 birch plywood. 1/8 has never been an issue and up to this point I just stayed away from 1/4 as much as possible… but I would really like to start working with it. 1/8 cuts at 10mm/s at 43% power, both min and max power is set to the same number. 1/4 I tried to slow it down a bit more(8mm/s) and do 2 passes and there are still always parts of the wood that is attached. I even raised the material closer to the lens which I saw in a youtube video, but no luck. There is the odd time with small test pieces it will cut 1/4, but then when I apply those same settings to a regular project it doesn’t work.

Is there anything that anyone can recommend me try that might help with this? Any settings or something I am missing? Any input or potential things to try is greatly appreciated!

Cheers,
Brett

I have a red/black 60W laser and discovered shortly after arrival that it wasn’t a true 60W machine. The tube had failed and the seller gave me a rebate, but not enough to cover a replacement. A few web sites will show you dimensions of the tubes available for a specific power rating. The original in my machine was specified in “someone else’s” chart as 45W, not 60W. It has been said in various internet locations that sellers will often provide a rating for a tube when operated at one hundred percent power. That power setting is a sure way to severely reduce the lifespan of a tube.

My replacement tube, a true 60W unit, was a bit larger in diameter than the original and about 300 millimeters longer, necessitating a home-spun extension on the cabinet.

The speeds you reference for 3 mm plywood is far slower than the numbers I use for my machine, which is expected, if your tube is not a true 60W. I have to slow my speed to about 5 mm/sec at 65 percent power (my tube max) in order to cut 6 mm material. Even then, it can take two passes to get through the bad glue or bad knot spots.

Consider to measure your tube and reference it to a reputable chart for size versus power. You’ll likely find that your machine is on the low side of expectations.

Well, let’s throw this in there. My machine is 50W I can cut thru birch ply 1/4 in one pass with one inch focal lens. (perfect focal is 21 mm but to cut I set at 19 so the focus is deep in the wood, not on the surface) 15mm/70% is my usual setting for ply cuts

I would guess you are hitting voids filled with glue. These are tough to cut through as the glue melts and re solidifies right after you pass the beam through.
It’s easy to tell if you are hitting glue filled voids as you cut. The laser will cause a very noticeable flare as it passes over the glue and it will make a sort of hissing sound from the glue flaring up. Also you will notice right around these spots there will be an area of dark soot from the glue.
Depending on your speed and number of passes you may not see until a second pass. I never try and cut even 1/8 in one pass as I don’t like dark edges.
Your laser is very capable of easily cutting 1/4 ply and even 3/8 ply but……it is going to fail if there are big glue pockets.
Look at the edges where it failed to cut…probably all black and nasty and you will see burnt glue.
Years back Baltic birch never had these voids an
As it was a cabinet grade wood and so the lamination process was excellent as you can’t have voids on an edge cut.
Sadly it’s all gone to garbage it seems…some are worse than others but I get voids in every suppliers plywood.
I have better luck with luan from Lowe’s and that’s sad.

Sounds good thanks @JBM3M

Thanks @shughey I will look at the edges of some tests to see and also possibly try out some other material options over the baltic birch and see.

Thank you for the details and input @fred_dot_u I will check that out and see. I am sure you’re bang on with it being less power than actually advertised. That along with hitting 18 milliamps at 43% power means I am getting very little wattage for cuts.

I should have noted that I’m using 28 percent as a max current reference, but with the “new” tube, the meter never reaches that level. I have a DooHickey from Russ and haven’t run the tests since I put the new tube in place, so I can’t say for certain of my power profile.