Is there a reason why the number of passes is limited to 50 passes ?
I have a optlasers 6w and using it to cut birch-ply i need 260 passes. (yes i know, and i have nothing more than time to wait until it finishes 
)
I can do this by creating duplicates and layering them with z offset always strating from where the earlier layer stopped. But its harde with complex designs.
Is there a way to reduce the limit or could maybe next updates remove the limit ?
Is there a reason that going slower isn’t an option? Or adding air assist? 260 passes is excessive - if it’s taking you that long, you’re likely carbonizing the material and reducing the effectiveness of the laser. A 6W should be able to cut 3mm ply in about 2 passes, running 3mm/sec with air.
Oz is absolutely right to call it excessive, you get nothing but ashes out of the many laps, believe me, I’ve tried running 20+ laps with my prezice focused 5.5W diode laser. “Normal/standard” 3mm playwood, there is no way, sorry.
I started with lasers maybe a week a go and the reusult that i get with around 200 passes 600mm/min is shown in image below.
with slower speed the burn mark on the surface is much worse compared to faster speeds, thats why i am cutting 600mm/min
The image described
The purple marked texts are the ones that was cut with 600mm/min
The hexagons was printed 150mm/min (and the purple marked lines goes through the material. the hexagons are not going through. The values above hexagons are passes and the z-step is the thickness of the ply (4mm) divided by the passes)
It may be carbonized inside, thats true
What i try to cut
The ply i try to cut is hardwood (birch) with 7 layer (the purple marked lower line) and 3 layer (the upper purple marked line) plies. Softwood ply i understand could be cutted faster with your given settings but hardwood i find hard to believe that could be cutted that fast, according to my tests.
Excessive air ?
The laser i use is optlasers plh3d-6w-xf and it has a powerful fan that blows air downwards.
So when you talk about excessive air, can you describe what you mean ? -> Is it like just some kind of small nozzle (5mm) blowing air and what is the source of the air, could it be a fan that conducts air through a pipe printed with 3d printer or similar ?
Those cuts look really wide, so I would guess that you are out of focus. Also, 600mm/min is 10mm/sec. You should be going closer to 2 or 3 mm/sec if you’re trying to cut through.
For cutting you want to “inject” air directly into the cut because it blows out fire, feeds oxygen into the cut, and clears smoke out of the way of the beam. Using a small compressor or air pump through an inflation needle works well.
Yes, the wide cuts are with 3mm/s or actually 150mm/min speed. And the focus is at 60mm. Its not very accurately measured int these cuts but focus is +/- 1mm
The narrow cuts are with 600mm/s and mainly because the cut mark is better with my current setup.
The hexagon text is engraved with 1000mm/min and the line texts 1500mm/s 20% pwm.
The text should state am i out of focus or not ?
Air compressor is out of the question. i dont want the compressor noise but if i would do it with some kind of fan, do you have any suggestions or links to a complete or printable known good solution for air assist ?
images below should show what kind of air assist it has from scratch.
Maybe it would be just enought to make a narrow nozzle to the aluminum nozzle shown in last picture.
But is it a no-go to “recycle” air in the enclosed system ? (the cnc is enclosed in a box blowing the smoke outside through the wall)
You do not need a shop compressor for air assist.
Loads of people use these kind of air pumps which you see a lot in the fish tank business:
Thats nice @jpjacobs . Do you think 60w is enough or more than plenty for lazer purpose.?
I might suggest you could benefit from a bit of research as to the effect of adding air to the lasering process to better understand the concept of what is happening. The volume of air and the pressure of the air being supplied are the important bits to evaluate. The wattage of this air pump is not.
This is an example of how to do this for a diode:
https://endurancelasers.com/how-to-make-your-own-air-nozzle-for-the-laser-cutter-full-video-guide/
Your laser looks really high-tech and I also think you have the “real” 6 Watts that are on the label. But, without an air nozzle, pointed directly at the focal point, it is very difficult to achieve a good result. Focus point +/- 1mm is not good enough, it should be 0 plus half of your material thickness, make a ramp test it always pays off.
May I ask what the laser costs?
There you can find all alternatives. from 450$ to 1000$. Most powerfull led is 12w
My cnc upgrade set costs around 900$ including powers, cables etc.
I found from my country a similar compressor for 49€ (~55$) which give 35L/min i.e. 2100L/hour.
Since this is very hard to know, and you guys at this forum propably are very experienced already. What specs do you recommend or does it need to be at least 60L/min ?
The one in this video is said to be 420L/min. https://www.youtube.com/watch?v=JmHXHqkt1Qk
http://www.hailea.com/e-hailea/product3/ACO-500.htm
seems to be 280L/min.
But its for a 10w laser. Just thinking that can overkill of the air amount affect negatively on cutting with lower power laser ?
you have to take all the air you can get, in my humble opinion
After thinking a googling hours and hours, i decided to go with a compact “universal” compressor that can be also used to other things also, since there is no silent air assist devices that would be good.
I found one that states 180L/min for around 85€. I’ll return for results when the system is setup and tested
So i hooked up a 59dB air compressor (it is really quite) BLACK+DECKER BD 100/6-ST
which states 105L/min air flow. With a tiny nozzle that i use that came with a cheap air pistol gets quite sharp and hard pressure.
Now the The lazer cutted 3 layer birch hard plywood very well. I couldnt see here when it went through but i blazed the upper cut-line 10 passes with 0.02 z-step and it burned it like a berserk 
with 100mm/min speed
The line above the purple markings was cut with 600mm/minutes and i didnt count how many passes i took but maybe around 20 and it went also through with a 1cm bridge left but i’m amazed how much the airpressure helps. Only problem is the “dust” marks left when the nozzle is blowing with ~45 degree angle from the front side of the laser beam. I probably need to get the air blown like the pro lasers pointed straight down from the beam hole.
Next thing is to create metal grid base so that i better see when it cuts thourgh and maybe the bottom side of the cutted material wont burn in that way.
Thanks folks for helping me out with this issue that got a little off topic 
