Sadly, I just have a basic one-speed-fits-all air assist. I’d love to be able to easily dial it up and down though, so I’ll file this away for the next time we’re purchasing hardware. Thanks.
You should consider a pancake compressor.
I use one and it is a Jewel for probably about $150
Just add a ball valve to your air line
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I have a Y junction in my airline. One goes to the laser head and the other has a short tube with a fish tank air tap which lets me bleed of some of the output. This lets me lower the output to suite the job I’m doing. Cheap but effective.
Great tips on the air assist, thanks.
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If the air flow is regulated, a lower air flow pressure should help…
I had to go from a pump to a compressor, I need more than the pump could deliver.
i set 99% and speed 100. if you have it cutting at 60%, it is generally super and the speed is 300!
What about using small as posible tabs and set the final cut on a different layer just for tab cutting, then you can adjust the air pressur to a minimium for the purpose of the small tab cutting.
What about using small as posible tabs and set the final cut on a different layer just for tab cutting, then you can adjust the air pressur to a minimium for the purpose of the small tab cutting.
Yeah, that’s actually a really cool idea. I was jostling that sort of thing around in my mind, but reading what you wrote concisely here makes me want to try this. It would presumably work on acrylic as well.
The problem with my setup in particular is that my air assist is completely manual (and currently having problems with laser misalignment with repeat cuts, even without moving the parts 
). The former I could deal with in various ways based on the above comments, and the latter I could conceivably work around by keeping the job going the entire time and having a “null layer” that moves around very slowly with the laser off or virtually off while I make the adjustment to the air for the final “tab-cut” layer.
For the stuff we’re doing right now I’ve moved to just rearranging and separating the parts on the layout, but when we move to acrylic for this I’m going to definitely keep this in mind. I think/hope that the air could be down to a trickle for just cutting tiny tabs.
I use small magnets to hold the main piece in place. I have some 10mm x 1mm rounds for lighter work and some 3mm x 30mm x 10mm bars that ar MUCH stronger.
(and currently having problems with laser misalignment with repeat cuts, even without moving the parts ).
Have you enabled $1 to 255 to keep the motors locked between cuts, just a thought, to eleviate movement of axis position between cuts.
Easy to check when machine is idle, if motors are not locked you wil be able to move the axis by hand with no resistance. you will know if they are locked as it will take some force to move them!!!
As for Air adjusting the Pressure, a simple small and quiet airbrush compressor with a small tank to stop air pulsing! will come with a pressure regulator, can pick up on E-bay for about £50 2nd hand.
It will probably runn nearly continiously, put a PC fan above the head, to keep it cool, works a treat and pretty quiet for the money
Unfortunately to provide the amount of air needed for cutting these little guys don’t do it. Pancake compressor is next step up.
Agreed that the small compressor, is on the limit but tbh I Have used one for some years, yes it runs continiously, with the fan on it it does stay cool, I ran it at 10Psi at the flow rate of 20ltr’s per minute, I did through the constant noise although only 60db upgrade to a larger unit with 25 ltr tank that delivered 100psi at 140lpm, but even now i do not go abouve 25 psi cutting 10mm plywood, i dont think that cutting thin materials needs a massive ammount of air, on a diode laser, the other thing that steered me away from the pancake style units was they are NOT oilless and have a very limited duty cycle, and the output of the lower cost units is not much greater that the little guy, as mainly used as low volume low duty cycle dental type compressors,
As for cutting acrylic, i never use air just makes for a nasty edge with a diode,just a trikkle to keep the disgusting lens destroying vapours of the lens, same with etching just to keep the path clean and the lens clean, but yes bigger is better, depends on the budget available, pankakes are quieter but a decent unit comparabe to a twin head oiless compresser is x 4 and of course if you have a large area it could be running for hours unless it is capable of running air tools with a large resevour.
Just curious how much air do you use for cutting plywood, as we see advertised unless Co2 and a fair bit of power most hobby laser manufacures have not much more than fish tank pumps, with exception of the Ortur unit , that does produc some pressure but little output, people do seem to get good results, buy I found no benefit waking the pressure up on material cuts, admitidly the thicker the material it does help clear the debris 
re: “Have you enabled $1 to 255 to keep the motors locked between cuts, just a thought, to eleviate movement of axis position between cuts.
Easy to check when machine is idle, if motors are not locked you wil be able to move the axis by hand with no resistance. you will know if they are locked as it will take some force to move them!!!”
I have not actively changed this, I was not aware of it! I don’t have the laser set up right now, so not easy to test.
I guess my offhand question would be why it works sometimes and not others. And why would it only be off by a sub-mm?
When the machine returns to home, if there is any and i do mean any tension in the cables or cable tracks , as the motors are not locked the smallest ammount of movement will show up.what is the point of homing if when the homing cycle has finished the axis are free to move until you press start?
I do when leaving the machine on but not in use between jobs sleep ($SLP) the Motors , then re home before the next job. saves the motors gettng hot when sitting idle!
Yeah, I was wondering if tension might be an issue. Especially because it was working fine for a few months (with really lightweight use, like maybe a couple hours of experimenting once every week or two.
That said, it’s not a matter of having the axes sitting around waiting to be bumped or something like that. Running two consecutive passes during the same run, whether that’s via a single layer with 2-passes, or creating 2 identical layers and letting them run one after the other, those both work perfectly. But if a 1-pass job stops and I immediately click start again, then it’s mis-registered.
I don’t have homing switches installed, but I did buy a pair for exactly this purpose. I’ll save the reasons why I haven’t installed for another thread. But there’s no homing or moving stuff around between passes, it’s simply a matter of the laser moving slightly away from the job when it’s done. Or so it seems.