I can see a custom vac table working for production purposes… a plate that has been milled with proper clearances to hold all the saved portions without getting cut by the laser. Of course, that is not a workflow that works well for one off diy projects the wife keeps coming up with.
Yeah, I’d kinda like something ready to go if I come up with some crackpot idea I want to try. 
I wonder if there is some way this can be tackled with some sort of dissolving adhesive. I am thinking along the lines of like how pla is used for dissolving supports on printers. Maybe something that dissolves in something that won’t kill the wood.
On a side note… not sure how ply compares to paper… but those sticky cutting mats work well for dragknife stuff. That may be a good compromise if the wood can be lifted cleanly too… this would get expensive though as those mats are not cheap. Nm… probably not good to breathe burned sticky pad lol.
Or the machine operator! It’s a whole new ball game when toxic fumes are in play. And I wonder what to believe, a number of things I’ve read say no laser cutting of ABS but I was looking at a cutter/engraver on Banggood and one of the answered questions said you could cut white ABS?
What solvent’s used to dissolve PLA? I know some where or another in the past I read of someone freezing material to the table for CNC machining. I was wondering if there was any potential in the material used to ‘dry-mount’ photos but that’s a wax so it wouldn’t be good if there was glue/paint in the future of your work piece.
Usually whit is PVC and black ABS but I’m sure there are exceptions IT will cut it it just gives off poison fumes 
Can and should are usually 2 separate things. Bone and leather are not toxic but the wife almost killed me for etching them in the house so I consider them toxic also 
Not that it means much but the Banggood blurb specifically said white ABS, to be taken with a grain if not the whole shaker of salt I’d guess.
I haven’t looked but I wonder if there might be something like low-temp hot-glue sticks that would provide enough hold and be easily released with a heat gun?
I clear the garage out and lock my dog out when finishing an abs print… before venting the heated enclosure. My garage has an excess of ventilation including a 600cfm exhaust fan. I could not imagine that in the house though.
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I don’t bother holding mine down too much.
I bought a piece of the plastic light diffuser stuff. I put my thin plywood on top of that. I tape down just the corners if I’m using forced air to help blow out the cracks.
Little pieces fall through the holes in the plastic as they’re cut out. The larger piece won’t move from the air blowing on it until the final cut is complete, so it doesn’t seem to be an issue.
I don’t worry about the bow in the middle of the thin plywood. What I’ve found is the laser seems to do ok with any ‘normal’ bow. If the plywood is extremely warped, I won’t use it.
I can gab a picture if this doesn’t make sense.
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Actually, it does. 
And thinking of the light diffuser material I guess it’d also be possible to drill a few hole and use a few strategically placed zip ties if need be.
All this talk has me primed to pull the trigger on a doide this weekend. Here’s 2 that are available, what do you all think?
https://www.amazon.com/NEJE-Engraving-Interface-Adapter-Suitable/dp/B08HV3BWPX/ref=sr_1_3?dchild=1&keywords=neje%2Blaser%2Bmodule&qid=1611284944&sr=8-3&th=1
Budget is not a huge concern, but I don’t want to dip into C02 laser territory and I read the cheap ones work great (if not better) than the pricey diodes. I read in other threads that the 2.5W lasers may be better… that the more powerful ones just have a larger dot. My thought is cutting time won’t be as much an issue for me vs the quality of the end results. So like if I can cut finer details with a 2.5W but it just takes twice the step downs of 7W, I am ok with that. However I can’t find any 2.5W doides available now, so figure 5W would not be so bad?
I do have a compressed air blast already installed on my mpcnc that I plan to use with it. I’m also running grbl, so pwm is of course a requirement.
I for one will be interested in hearing if that’s the case, maybe too many years fooling with bikes/cars thinking more power is always more better. 
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My first laser was a 3.3w. The less powerful laser would not cut through 1/8" plywood. It didn’t matter how slow you went or how many laps you took around the design, it would only cut so far and then it seemed to stall. I’m talking, 10 laps at 1 mm/sec. If you start going too slow, the laser creates more char and can’t seem to cut past that.
After upgrading to a 7.5w laser, it cut through the 1/8" plywood in 3 laps at ~ 2 mm/sec.
While the smaller laser might have a smaller beam, it also takes longer to burn/cut the design. And we’re talking ‘microns’ here in beam difference. We’re not saying the 3.5w is ~1mm and the 7.5w is 3mm. We’re talking fractions of a mm difference. Time makes a huge difference in useability. One of the first things I burned took 4.5 hours. I can run the 7.5w laser roughly twice as fast. That’s a lot less time having to babysit the machine on a larger cut.
Also, you need to consider how you’re going to interface it to your controller. You have the TTL board selected, which I think will work fine with the Marlin controllers we’re using with the MPCNC. I had to get the PWM board to make it work with my GRBL board on my engraver.
This is the one I ended up buying. Looks like it’s currently unavailable.
https://www.amazon.com/dp/B08ML93ZJQ/ref=emc_b_5_t
I don’t have much going on today. I’ll spend some time in my shop taking pictures and doing some test burns. Anything in particular ya’ll want me to test/do?
Hey David, due to the lack of availability I ended up with the 3.5W oxlaser. I was very tempted to go for the 7W neje but price and skepticism got the best of me.
I have worked with it for a bit now, and found that 1/8" ply typically takes 10passes at 20mm/sec. 1/8" balsa in 3 passes at the same speed, but depending on the grain quality really (heavy grains can take 6 passes to get through). This is with a pretty strong airblast though, and a vented grid type table.
I am sure the 7W would be much faster for cutting, and now I’m kinda lamenting not spending the extra on it. I have not figured out how to get through 1/4 ply yet, even with… I forgot how many passes… like 50 at 16mm/s or so. Maybe if I slow it down it would get through.
Have you gotten further with cutting 1/4 materials?
I spent last weekend cutting more stuff out of 1/4" ply for the wife. The 7w definitely does it better. I did have issues with my settings being not quite perfect for the cheaper plywood I am using. I had to re-cut a few of the designs because the first one didn’t quite go all the way through.
You’re running into the same issue I had with the smaller laser and thicker material. Once the material gets a good char inside it, it seems the laser just stops cutting any further.
I know the 7w is pricey compared to the ~3-3.5w, but for me it was well worth it. I just wish I had saved the money from buying the initial laser.