18 Stainless steel Boss 3655

I have an HP 3655 150 watt laser
I am trying to cut 18 gauge stainless steel.
I have cut it once before about 5 months ago.
so here are my settings.
Power 90 Speed 10
Cut through start and end = 3.00
So after getting an excellent calibration, I send the
project to the laser.
The laser head moves down the oxygen comes on
the laser fires, the head moves back up and the
whole process begins again and continues until
I stop it.
Any help would be appreciated!!
Thanks in advance!!


Not many people have a metal cutting head on their laser. You are sort of a unicorn with your setup. :slight_smile:

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Yeah I am starting to feel like that!! Thanks for the reply tho!!!

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Can you post the LBRN file here, or send to Support@LightBurnSoftware? It sounds like you might have something odd in your settings if it’s not following the path of the part, and just doing the start / end points.

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circle test.lbrn (11.9 KB)
Thanks for any help!!!

You have perforation mode enabled, and a kerf offset. Are these intended?

No sir. I do not even know what that does.

Double-click the entry in the cuts and layers list. Turn off Perforation mode (make the toggle red), and set the Kerf offset value to 0. Then re-run the file.

Wow…That definitely helped!
So now it is going thru the cutting motion.
After adjusting the oxygen it kind of cut thru with a splatter effect.
So I adjusted the oxygen some more and it quit cutting and just
marked the stainless.
I adjusted the Oxygen back to 100 and still the same.
I adjusted down to 85…same thing. I adjusted up to 120 same thing, barley a mark.

For the actual cutting settings I’m going to refer you back to Boss’ support - they should have guidance for this, and I haven’t worked with metal cutting or oxygen feeds before, so I’d prefer not to kill you with bad advice. :slight_smile:


Sounds like you have an oxygen problem either not enough or not hitting at the right spot any acc and the proper oxygen it should cut

OZ… I really appreciate you. Have gotten ALOT of insight redaing your responses to peoples questions. You are the Main!

Jimsher…I think you are right…I was running out of oxygen so that may have had something to do with it.
I am getting my tank refilled now.
Will let ya know how it goes with a fresh tank.
Thanks for your response!!

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Did you get the issue resolved? I’m still in the process of getting metal cutting dialed in but have a couple ideas I could share if you’re still working it out. I have a Boss HP-2440. It seem to me that the power and speed should be about right though. I’ve only cut 22 guage mild steel and stainless so far.

No I have not. I refilled the tank and got busy with other projects. Would love to get this right tho!!

You might already be aware of these things but here’s my 2 cents worth.
Make sure the ground wire is attached to the piece you’re cutting,

Did you have your air compressor running? I initially thought when in follow mode compressed air wouldn’t flow. I need to test to be sure but I now think it does. So air could be mixing with the Oxygen causing a poor or no cut-through.

Is the period in your cut through time a typo? “Cut through start and end = 3.00”
I’m thinking you meant 300. If so that’s about what I’ve been doing. 250 to 300. That’s on 22 guage though, 18 guage might need more delay and mine might be longer than necessary.

Do you have any thinner material? 18 guage is the max SS cut thickness for the laser isn’t it? In my experience with trying to learn a new cut process or machine starting out at max cut thickness would be tough.

Another variable with the metal head is that the lens is in the tube that screws on from the top and the cone threads on from the bottom so it seems to me that the focus could be off quite a bit based on how far the bottom end is threaded on. I wish I would have measured mine before I used it. I don’t think I’ve changed it from where it was but I wasn’t paying much attention to it initially so could have.

Ground wire yes.
Compressed air disconnected, Oxygen only connected.
3.0 was not a typo in the cut thru time, however I have tried it with 300 and down to 0. No change at at.
I have tried thinner material and get the same results.
When I first bought this machine I actually cut 16 gauge stainless with no problem. So I am confused.
I have adjusted the lens up and down quite a bit.
I sure do appreciate your input!!!

Strange that it was working well before but not now. I’ve been wondering about the focal distance also. With the cone being threaded part way on from the bottom and held in place with the hand tightened locknut it opens a possibility for that to come loose, get turned in or out a bit causing the focal length to be changed. I think mine is pretty much where it was before I started using it but I wish I had taken a measurement or counted how many turns it was threaded on so I could be sure.

I’m having trouble with follow mode. I’m not getting the raising of the head and recalibration at each new pierce of a cut file or height adjustment of the head while cutting and no matter what I set follow height to after calibration the cone is about 3/16 off the material.

I’m not getting cut through at that height on 22 guage stainless but if I lower it manually to around 3/32 I get a real nice cut. That’s the only other think I can think of. Don’t know what you’re running for a follow height but maybe a little closer to the material would help if you’re not already there.

Is your follow mode working properly? Have you had any problems like I described above?

Only a suggestion, if you haven’t already tried this, but what about cleaning the lens if it’s been a while since you first had success? I have no metal cutting experience beyond stainless shim stock with air only - very crappy results but it was just a fun test for my home built machine. I do know that my lens gets dirty quickly through my testing on various materials and I clean it fairly often.