Laser cutting a 1x4

Does anyone have cutting numbers on a poplar 1 x 4? I want to cut down some 3/4" thick poplar to make the rest of my box, but don’t want to damage anything.

Not sure it can be done to any level of satisfaction.

ah… really? that’s fair. I can cut 3 copies of the other material i suppose.

Not sure if you’re looking for qtr inch or three-quarter inch. I’ve done qtr inch and think I started with the PG Maple settings. I’ve done pretty thick poplar (either half or three quarter - I’ll have to check). Cutting that required multiple passes but was still a good cut and not all charry or burned up. I can’t access my project log right now but I don’t think it took more than 3-5 passes as I’d not have patience for anything more :slight_smile:

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Wait… Is it not supposed to be black along the edges? What do you do to get it more of a brown color? We’re using qr code material, so I just assumed everything was on the level but it was pretty charred.

You want the power/speed to just cut through - that results in the toast color on most materials. Black (especially wipe-it-off black) is either too much power or too slow a speed. This is where running calibration templates helps a lot.

For really thick stuff - 1/2"+ you’re going to need multiple passes. When you do that, you’re going to want to up the speed or dial back the power. You may find that 3 passes of full power at X speed will work but result in black charring (or even burning) but that 4 or 5 passes at 100 power and X or X+ speed reduces or eliminates the black.

The first time I start using any material, I will run a series of cut & engrave tests to get a sense of how the material lases. That gives me a starting point for any real project I’m going to do. I keep those test samples and Sharpie them with the settings so I can grab it off the shelf and have the starting values I know will likely work pretty well.


I’m confused the post’s title suggests you want to cut a 1" x 4" board, but in the text you mention 1/4 poplar and maybe using a band saw to re-saw a 3/4" board into what would presumably be a bit less than 1/4" thick boards???

If you want information on cutting 1/4" thick poplar, at the bottom of this long post is my experience.


A 1x4 in the US is generally 3/4" by 3 3/4" (ish)… I’ve been told it’s a way to cut costs but that could be totally made up. I would guess it’s just shorthand. I am working with a 3/4"x 3 3/4" 1’ piece of poplar.

We bandsaw 1/4" thick boards, sure, but I’m experimenting trying to figure out if you can simply cut a 3/4" thick piece from our excess materials. After some experimenting, it’s doable, but definitely not time saving. After 5 passes, it began having flare ups and so I cut the run as I didn’t want to smoke out the lens and potentially damage something. We’ll stick to 1/8" and 1/4" boards for now.

The confusion came from your text in the original post. The title said 1 x 4 but the post said 1/4.

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Ah, I see now. Got it. I changed it to a 1x4.

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Not made up. It’s based on the old green vs dried lumber dimensions. The green wood was cut to 1x4" and it would dry to something less. Most all commercially sold wood is now kiln dried and ends up with a pretty standard size - not many people build with green wood.

The made up stuff is plywood. It used to be that half inch plywood was half an inch thick. Now it’s 15/32 or less. Since ply is manufactured, they slice the veneers a little but there’s no drying or other post-manufacture process changes that affect its thickness, just extra profits from every 15 sheets. :slightly_smiling_face:


I just did this with Oak instead of poplar but I imagine its pretty close to the same. I removed the crumb tray and stacked two pieces on top of each other to get 1 1/2". Then using proofgrade Medium oak settings I was able to get really good cuts from that. For my project I didn’t need amazing accuracy but from what I can tell it worked great.

I’m still confused. 3/4” is really thick. Thats like 19mm.

Hi, could you please share the settings you used to cut 1/2" thickness?
I’m trying to cut 1/2" plywood and haven’t been able to yet
Thank you!!!

If you ping me next week I can check. I’m on the road for business now though so can’t look now.

I did Poplar which might not translate to 1/2" plywood though. Solid wood, especially one as relatively soft as poplar is more consistent than plywood with its multiple layers and unknown glues. Plywood is some of the toughest stuff to cut because of the glue, embedded knots and voids that are all invisible. Testing with multiple passes is necessary which is how I got thru the poplar hardwood.

Got it! makes sense. I’ll send you a note next week to check
Thank you!

If I were going to do this, I would use three or four separate cut lines stacked on top of each other (no fill, just stroke), of different colors. That will force the UI to do them in separate stages, so you can go in and manually set each one at a different (lower) focal height. The way you tried it, your laser was focused at the top of the board, and on each subsequent pass you were that much further off. As the beam reaches down into the cut, it becomes increasingly de-focused on the current height of the cut channel, and will cut worse and worse, increased charring and all the bad stuff you experienced. Try this one again with staggered focal heights and I bet it will do much better.


Good suggestion.