I’m having a heck of a time cutting through 3mm Baltic birch plywood. I have run it at 100% power at 2 mm/sec , 6 passes, and not getting cut throughs. I was just wondering those with 50 watt lasers what settings are you using to cut through 3mm Baltic birch plywood?
Thanks
Bob
I can cut through 3mm birch ply in six passes with my 7w diode.
There is something not setup correctly there. I would expect yours to go through in one pass easily at a fair speed.
I’m using a 60 watt (real 60 watt tube) at 25 mm / second and 65% power for a clean single-pass cut.
You’ll want to measure your tube and use TheGoogle to determine your true power for that laser. You’ll also want to locate the maximum recommended current draw for that tube. If you don’t have an ammeter in series with the ground lead of the laser tube, it’s a valuable accessory for getting the longest life from your device.
Running your laser at 100% means you’ll be reducing the lifespan of the tube. At the speed and power setting you’ve noted, it’s possible that you’ve reached the end-of-life for the machine.
100% on both Min Power and Max Power? Or just Max Power? Your profile says, “Chinese Laser” for the machine type, which is like saying, “my car has wheels”. 
If you have a Ruida controller, at or below 10mm/sec, the controller uses the Min Power value only, so if you are doing really slow cutting, and aren’t setting that, that’s your problem. If you cut at 10.1mm/sec or higher, the controller ramps from Min Power up to Max Power as you get to the requested speed.
This lower value is also commonly called ‘corner power’ as it’s the power setting used when the controller slows for sharp corners.
Oz, I do have both settings at the same power level. I am just curious as to what others with a 50 watt Chinese laser are cutting 1/8 Baltic birch plywood with. I want to find out if I am expecting too much or this is common or am I around the settings. Nothing scientific, just seeing what others with the 50 watt are doing it with.
Bob
Have you done a ramp test to check your focal length? I would recommend doing that if you haven’t.
Also check to see if your beam alignment is correct. If the beam is hitting the nozzle on the way out, it will make the nozzle warm, and the beam weak.
I’ve got a 80w chinese red&black (Ruida controller) and cut 3mm Baltic birch at 35+mm/sec and 65% “indicated” power in a single pass. 65% gives the maximum allowable current for my tube.
If your machine won’t cut it at 15-20 mm/sec in a single pass then I think something is wrong. Bad focus, mirror misalignment, etc.
5mm plywood, 700mm/min (12mm/sec) 80% (18Ma). 50Watt cloudray tube. Singe pass.
Hope that helps
David
50W Cloudray Tube in a Blue and White Chinese Laser
6mm Ply @12mm/sec 68% Power
Make sure your focus lens is in correctly. It has two sides, a convex side which is a slight hump and the concave side which has a slight indent. The convex side should be up in a concave side should be down.
60w tube
4.5mm ply@18mm/sec 65%power one pass.
Are you sure that you don’t have a ply issue. I had a bad batch not so long ago and I had terrible issues cutting it. Would take 3 to 4 passes but then the cut edges were burned so black leaving black soot all over the face of the ply and not the nice golden brown I would get normally.
I changed the batch and I am back to good cut most of the time.
It was upside down, Imagine that. What is the best way to clean a lens? Mine has a lot of buildup on it now-I’m going to try and clean it with denatured alcohol. Its caked on pretty good since I have been playing around with it in wrong for a couple weeks at very high power
Bob
I’m glad to hear it was an upside down lens. Alcohol and a very soft cloth is the best way to clean your lens.
That’s great news, easily done.
Glad you found it.
Cheers
David
So I replaced the tube on mine with a tube from lightobject. 3000% better. Found out my tube was a 30w tube not 50.
My 50 watt is stock. With clean lens and proper focal length I cut 3mm birch at 35% power and 10 mm/sec and get nice clean cuts.
FYI, I know you had your problem fixed, but I thought I would add something that I ran into yesterday. I was trying to cut through 3/4" Spruce, and after 10 passes at 80% it wasn’t cutting all of the way through, not even close. I changed the cut settings so that the minimum and maximum was 80% and it blazed through it in 2 passes.
(130w)
Interesting. I do 20mm/s @ 80% with 2 passes. I’m going to have to try your way too and see how that does.
I should have added that is with one pass on the 1/8". I also cut 1/4" at 50% power and 12mm/sec in one pass with clean cuts.
With a light object 35W tube we can cut 6mm baltic birch with one pass at 5mm/sec, 16mA tube current.
here’s the tube.
https://www.lightobject.com/Laser-Tubes/SPT-35W-CO2-Sealed-Laser-Tube-for-Small-K40-Laser-Engraving-Machine
Can’t say enough positive about LO tubes. We’re now into the 4th year at our Makerspace (150 members) with the same 35W and 45W laser tubes.