Are my results within the norm?

Hi all,

I’m trying to cut 3mm Baltic ply sourced from Woodcraft.com with an Atomstack S10 pro diode laser (10 watt output) and lightroom 1.3.0, and have been getting strange results.

After cleaning the lens and carefully refocusing on the material, it’s still taking me 16-18 passes at 90% power and 1100 mm/m to cut through and even that’s a bit inconsistent.

At much lower speeds the more complex pieces with thinner walls tend to burn away. I’ve attached the Lightburn file I’ve been testing with. The spiked wheel is approximately 31mm in diameter.

My question is, is that a normal power, speed and pass range for this kind of material, or should I be questioning the material’s density or the output of my laser?

Thanks for your help.

Jerry Kornbluth
Wheel Test.lbrn2 (84.6 KB)

I’m not familiar with your specific laser but in general I’d say that your speeds are unusually fast. I’d expect to see these speeds more in the 200-300 mm/minute range.

Are you using air assist? If not, the scorching you’re seeing doesn’t surprise me. The glue in plywood can be quite difficult to cut through. You may want to try this with a similar thickness of solid wood to see if that makes a difference. In any case, your speeds are likely at least 2x where you would normally expect to be.

Thanks for the quick response.
Sorry, yes I’m using air assist, and it’s more than scorching. Some of the fine detail (like the wheel spokes) are thin and some of them burn away at lower speeds, even with 40 or 50% power. The only way that I can think of to get them not to burn away is to increase the speed, then I can raise the power.

If you’re using air assist then yes, I think your results may be deviating from the norm.

I’d suggest testing on some other materials to gauge relative performance.

If you haven’t already, you may want to run a material test and check results systematically.

Can you upload a photo of some of your results?

Some things to look at, you mention focus but make sure your focus is spot on. Make sure your lens is spotless. Even a small amount of residue can diminish performance. For your air assist make sure the air is aiming directly at the cutting line. If you can decrease the distance from air to material that’s also desirable.

I have just tried your file and here is my results.
Note: Marks are from previous etching on this scrap testboard.




Cut from a scrap bit of 3mm ply with Atomstack laser. One pass, no scotching. 75mm/m 95%.

Hi Ron,
Thank you for all the time and effort that you put in to this.

Are you using a 5, 10 or 20 watt output module on your Atomstack?

I’m away and can’t try this with your settings until tomorrow, but it’s intriguing that it worked so easily on your rig.

I’ll definitely report back and try to figure out why there’s such a discrepancy.

Thanks again,

Jerry Kornbluth

My Atomstack started life as a A5 basic model. I upgraded the head and driver board to their 40w model, which I believe puts out 5-6w laser power. Has very small focus dot which is better than the head that came with the machine. Does all I want of it and seems quite well built.

If the plywood isn’t made for laser cutting it probably had formaldehyde glue (not melamine) which both makes for charred/difficult cuts and produces nasty fumes. This could be contributing to your troubles (in addition to the power and speed). Have you tried our materials test tool (after confirming the plywood is a laser-kind)?

Billie Ruben has a very good point here. I only ever use laser plywood. If your material is just any old type of ply, then don’t use it on your laser machine. The glue in some plywood is very dangerous and extreamly hard to cut.

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Hi Ron, Billie and Berain,

Thanks for staying involved with this.

I haven’t had any better luck with your settings Ron, even when I upped the speed to account for the 10 watt output. I haven’t done a proper materials test yet based on your settings but I’m still getting lots of burning and no cut through when trying a series of low pass count settings.

I’m going to take a sheet of the stock I used to our local library where I can work with their laser cutter to determine if the plywood is the real culprit here. I haven’t had this kind of issue before with other materials although they were mostly much softer. (My appointment is tomorrow so I’ll report back then.)

For now, can I please ask where you folks source your 1/8" baltic plywood and other wood materials.

Thanks

Jerry Kornbluth

eBay is my source. I buy from who ever offer the best deal plus I only buy Birch or Poplar grade A/B laser safe Ply. Most times I only cut about three quarters with first pass as this prevents large amounts of smoke getting to the underside and staining the product. Just my way of doing it.
Looking forward to seeing how you progress with this problem.

Hi Ron,
Thanks for the reply. I can’t seem to find anything but B/BB grade. Have you bought from Woodpeckers before? Any particular sellers you trust?
Jerry

My last purchase.

Thanks Ron,
Didn’t know you were on the other side of the pond.
Shipping to the US is a bit steep, but there’s cerainly more available than here.
Anyone know of a dependable US source? I got my last (and only) batch from WoodCraft.
Thanks,
Jerry

Hi Jane, and all.
Well, I’ve returned from the library with some good and inconclusive news. They have a new Glowforge that’s unfortunately CO2 only (no diode) and it cut my pattern on my stock like butter, in one pass with extremely little scorching.

This still doesn’t determine whether it is the stock that has an issue or it’s something with my rig.

Is there anyone out there, in the US, who has a 10watt output laser diode machine that would be willing to cut a test with the test file in my previous post above (wheel test.lbrn2) and a piece of my 3mm baltic birch ply stock so I can definitively rule out either my laser or the wood? I’d be happy to send them a sample piece of my stock (originally sourced from WoodCraft).

Thanks,

Jerry Kornbluth

Running the gear on my 10W now on 3mm balitic I get from the local hardware store. Will post a pic soon.

A bit of cleanup on the smoke stains and should be good.
Maybe head to the local dollar store for a few pieces of there craft plywood. Probably help to know if it is the wood.

edit: most if not all fell out after 2 passes.

image

Thanks for doing this, Mike.

I’m a bit hesitant to buy plywood from the dollar store since i have no way to tell if the glue/binders are laser friendly or not.

I’ll try your settings and see what happens, and post the results.

Best,

Jerry Kornbluth

Hi Mike,
The results were very promising. A few tweaks to get it to work with a little less charing, but almost there with 3 passes at 250mm/90%. At least I’m now pretty sure that it’s not an issue with the laser module itself.

I’m going to try a materials test using your numbers as a baseline, and also try a focus test instead of relying on the 2mm Atomstack focusing rule and see if that make any difference.

I really appreciate everyone’s time and effort on this.

Again, thanks!

Jerry Kornbluth

I have a Ortur Master 3 (10 watt). I just cut out your wheel and pins. My setting is 150mm/m and 50% power with a single pass. Kerf was .057 (that is for my laser). When i called you wheel, your setting were 11000 mm/m 90% power, 16 passes and no Kerf setting. The number of times I forgot or just typed in the wrong setting were many. I would start fresh.
Red Raven