Hi
Has anyone tried to use Print and Cut to cut on two sides of a 3mm ply sheet? I’m trying to cut ply and reduce the kerf that results for multiple passes. So maybe use the laser on side A for 2 passes and then flip the drawing and cutting on side B - just wondering
Matt did a video on that, some kind of ornament if I remember right. The key was to make the registration marks as cuts that went all the way through.
Matt I think uses it to align engraving on both sides but I don’t see why the approach wouldn’t also work for cutting. However, I’m not sure if this will get you the benefit that you expect. Even with the accuracy of print & cut I suspect you’ll be just slightly misaligned so you’re likely to feel or see the transition between the cuts from both sides.
An alternative method for you to consider is to setup some sort of jig where you could place the material reliably that would allow you to flip the material to a high degree of accuracy. If you were doing this repeatedly this would be faster and less fussy than trying to do this with print & cut.
But candidly if your target is 3mm plywood you’re probably better off trying to dial-in your setup and settings to cut through 3mm plywood cleanly from one side.
Then other thing to consider is your lens’. A longer focal length has a narrower beam cone, and the GaAs lens’ even more so. I use a 4" GaAs lens for all my foam cutting.
@Dave01 I do a lot of XPS foam cutting with a diode laser and have been curious about how much a CO2 laser might benefit. Do you happen to know the kerf size you’re getting when cutting foam? Are you cutting XPS? What thickness?
I’m cutting 3mm plywood veneers with a chipboard center - it takes 5 passes at 100% and 70mm/min on the 20W Ortur - regular plywood gets cut in three passes -
and getting about 1mm kerf which is too big
I think you’re right - too much alignment issues especially on complex designs - I need to find veneer plywood that allows me to cut in three passes vs five - regular plywood cuts in three, but the particle-board veneer stuff doesn’t cut so cleanly
I cut 1/2" and 1/4" cross linked for tool box liners with all the socket and wrench cutouts. I can’t say right off what the kerf is, and even with the 4" lens it’s still not quite a square cut but it’s close. It’s not a large kerf, and I cut at max power and just slow enough to cut through. If it doesn’t have the paper backed adhesive on it I can cut about 20% faster. I’ve been playing with the idea of cutting it ‘upside down’ with the bottom paper backed adhesive on the top, but I’ve had too many other projects going to get into it.
Back when I was first starting with it and tried the 2.5" glass lens it took several passes and the angle of the cut was visible. With the 4" GaAs the only way you see the angle is when I stack multiple layers for thicker boxes.
Higher quality ply will cut much better, too much / inconsistant resin layers in the cheap stuff. What type of veneer? Baltic Birch is supposed to cut pretty decent. If you get it in 5’ x 5’ sheets, then you have the authentic stuff from overseas.
FYI, I cut 3mm MDF most of the time. I had been recommending the double refined, but my supplier had a problem, and I got some single refined made by a company down in Brazil, and I actually like it better for the laser. A LOT less resin on my bed rails.
OH, and Zep Purple and water 1:5 cleans the resin off real nice. A ten or fifteen minute soak and they are clean. I get five or six cleanings before I have to mix a new batch.
Are you using the veneers as an inlay or something? What’s driving the need for a thinner kerf?
Also, do you have air assist on your setup?
Thanks for the perspective.
We’re cutting different types of foam but cutting bottom side up would never work for me because I’ve noticed the cut from the top side is much cleaner than the cut at the bottom. To me it looks like the top is being “cut” while the bottom is basically just melting away. The kerf at the bottom is visibly wider at the bottom than the top even on 1/4" material.
I got some sapele and ash from a place called boulter 1/8" https://www.boulterplywood.com/MarinePlywood_4.htm - I probably got the wrong stuff and the inside is very pock-marked and rough when I cut…
I do have air assist - and I thought I had a good setup - one thing thing that I need to test is whether to do more passes at higher speeds vs less passes at slower speeds - hoping to avoid excessive heat etc -
The more adhesive and inconsistent the ply the harder to cut consistently I’ve found.
In general I’ve found more passes at less power leads to a cleaner cut with less charring once you get past a couple of passes.
Do you have your air assist aiming directly at the point of the cut?
Foam cutting - Play with your focal point. I have better luck with foam setting my focus a few mm into the materiel.
Air assist. I went with the little included pump, but was getting ‘dirty’ cuts. Switched over to my big shop compressor and regulated it down and now I get nice clean cuts.I run a Cloudray No3 nozzle, and run around 5 psi flow pressure for acrylic. For my 3mm MDF, I run between 12 and 14 psi flow pressure depending on moisture content of the MDF. ALWAYS run an air drier, the moisture in your air supply will kill your lens’!
I’ve experimented with this a bit. Focusing deeper created a slightly squarer cut but sacrificed the crispness of the top cut which is paramount for my needs with foam. I’ve done limited testing of this on hardwoods but haven’t yet come to any conclusions.
Thanks for this. I hadn’t considered this.
The little diaphragm pump that comes with your laser will never build up moisture. A larger compressor with a tank has the capacity to hold moisture, that’s why it has a drain. The moisture will be suspended in the pressurized air until it gets past the solenoid or nozzle, then the moisture comes out and collects somewhere cooler as the pressure drops. Usually the inside of the nozzle and the bottom of the lens.
My big compressor builds up to around 130 psi. I have a step down regulator at the laser down to 60 psi, then 5 and 14 at the laser itself. My drier sits between the 60 psi regulator and the laser.
LOL, I’m US, our plywood sheets come in 4x8. My understanding is that the European standard is 5x5. I have one supplier that stocks the Baltic Birch in the 5x5, and it is a MUCH better quality than the US 4x8. I only used it for a while before switching to the MDF for stability in the thinner sheets, but the extra cost was well worth it for the 5x5.