1/4" birch cutting issues

I’ve had my Glowforge Pro for a month and I’m having some issues. I love the Proofgrade materials, but for the majority of what I am making I need materials with no finish on them. So I have been trying to sort out the settings for 1/8" and 1/4" birch plywood. I’ve read pretty much every post I can find on this issue and used some of the tips suggested by @TexanGothic, @jules & @davidaspitzer . Nothing has worked with any reliable certainty. When trying to cut 1/4" birch plywood I am having all kinds of issues. I have had decent success with the 1/8", but the 1/4" is a mixed bag. More failure than success. I wish Glowforge made a wood proofgrade product that doesn’t have a finish on it, but they don’t. I’ve tried 3 different suppliers of birch plywood and they are unreliable. I tried @davidasptizers speed tests to see if I could sort out the settings, and I did tests from 150 down to 110 at full power. The best cut was at 110 but the wood scorches around the edges of some of the cuts. I would prefer not cutting everything twice out of 1/8" and then gluing them together as some have suggested. That’s a lot of additional work and not really how I want to go about making these complex pieces. Any thoughts on what I might try?

This will be unpopular, but unfortunately, the glowforge is not the ideal tool for this.

You’re looking at a long frustrating process to try to get a 45w laser to reliably cut 1/4" ply, and it’ll end in failure if reliable is key. It’s just not the right tool.

Upgrade to a 60-100watt laser by someone else if 1/4" is key to your plans. Otherwise, get comfortable with 1/8" is my best advice.

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i will say this. if you’re looking at 1/4" birch, but not 1/4" BALTIC birch, you’re making a mistake. the baltic birch has more requirements for what the interior substrate consists of, so you’ll have far more consistency when cutting. generic plywood can be all over the place. both in interior substrate as well as quality control (think “voids” and poor materials).

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Definitely use Baltic Birch. Regular plywood sucks from a consistency standpoint…there are air pockets, glue plugs, knots and even Bondo inside it, and that can be impossible to cut with any laser. (Any of the above will cause that scorching you’re seeing.)

The baltic birch is manufactured to a better quality standard. There might still be an occasional issue, but a lot fewer.

Amazon is a good source for it.

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amazon is good, but if you can find a local supplier who will cut down sheets for you, it will be a lot cheaper per sheet. especially if you need it in any great volume.

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I appreciate your honesty and your feedback. What’s been challenging is that the 1/4" does cut beautifully, some of the time. The first sample cut of one shape was perfect, but the more complicated designs have been a bust.

It’s baltic birch.

Thanks @jules. I read the posts about plywood before ordering it.

Thanks @shop.

Even 1/8" baltic can vary and be inconsistent. It’s a great material and I use it a lot, but occasionally you get a weird batch or even just a local issue.

There are ways to help identify this in 1/8" to an extent, but even then you’re not guaranteed anything:

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Thanks @evansd2.

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Hey Dac,
Yeah I’m sorry you’ve struggled with that. I’m sticking to 1/8" personally. I like the golden edge and have found a workflow that works for me with very consistent results. But yes, gluing together is time consuming and messier. But I know your pain, it would be awesome to have 1/4" with the golden edge and reliable cuts.

-Brad

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I have ventured into 1/8" wood and not so happy with it. I use mostly 1/4 but all the way up yo 1/2"
These folks have consistent quality of Baltic Birch at prices that are as reasonable as reasonable for the quality and service…
Ocooch Hardwoods - Supplier of Thin Wood for Scroll Sawing, Carving Blocks, Intarsia wood, Plywood for scroll sawing, and more.
I had no trouble cutting and engraving this out of 1/4" Baltic Birch…


with full power, 350 speed

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Thanks, Brad

@rbtdanforth , I ordered some plywood from Ocooch this morning before I posted. I’ll let you know how it works out.

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See if you are getting real Baltic Birch - your suppliers may be providing plain Birch plywood (birch veneers over who knows what inner plies vs baltic birch veneers over baltic birch plies). Ask for a full sheet and if it’s not 60"x60" it’s likely not BB.

Then if you’re getting scorching at 110 but it cuts through, try something like 150 & 2 passes or 200 & 3 passes,

If you want to get really tricky, make as many copies of the item in your design file as passes - then color each one differently. Stack them on top of each other and in the GFUI set each one with the same power/speed and 1 pass but change the focus height to the material thickness for the 1st pass, 1/2 the material thickness for the 2nd pass and 0.1 for the 3rd pass (if you do 3 passes). Each one will focus lower in the material and clean the cut above it a bit as well as cut more with less (or no) charring/blackening.

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I know the Menards Baltic birch is a different breed. It’s “Baltic birch” but 4x8’ sheets - the kicker is that the 4x8’ sheets use an exterior glue rather than an interior glue like the 5x5’ sheets.

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Thanks @jamesdhatch. I’ll try these suggestions. I appreciate the help.

Which is not permitted in the BB standard (there’s an EU standards definition that applies - kind of like champagne).

There is some standards compliant BB in the 4x8 size made by some Russian companies and I believe there is one domestic manufacturer that makes it as well but it’s a special order large dollar product - I doubt any mass marketer like Menards would ever sell it.

The whole point of the standard is that it’s consistent. Different glues don’t support consistency. And that’s a big issue in laser cutability.

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@jamesdhatch , I tried cutting several pieces of 1/4" baltic birch with your suggestion of 2 - 3 passes at 150-200 today . I had mixed results so I tried a low tech version of your suggestion of doing 3 passes at different focus heights. That seemed to do the trick. It took 4 -5 tries to get the settings right, but I had about a 95% success rate. I just made three custom settings and cut the same design 3 times doing one pass at 200 full power at .23, one pass at 200 full power at .115 and one pass at 130 full power at .1. That cut fully through @95% of the lines. Most of the pieces just fell out and the few stubborn ones just took a couple of swipes of an x-acto knife to release them. Many thanks for the suggestions. I really appreciate your help.

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