Focal Inch Data for .5 HRS

[LaserApprentice]

Referencing a previous thread "Cut Conditions for Mild Steel"
First of all I am a pretty new operator that mainly has experience in cutting thinner material (0.23-.097). I now am cutting up to .5 inch on an Amada FO-4020.
my cut is super jagged on the edges. This machine is new to the company, however is not new by any means. I believe the mirrors either need to be cleaned or replaced.
I just can not seem to convince my superiors. So I am trying to find any data on cutting conditions and track my progress. The Post I referenced is where I have
questions. The post has mentioned focal +.05 but another says I need to have a negative(Convex/Concave) I am just not sure where to being with trying to find out what negative
I need.
1/2 HRS
Feed Rate: 45.00 Pwr: 4000 Freq: 2000(Don't think this matters bc of Duty) Duty: 100 GasP: 0.08 Nozzle Gap: .03 Focal: - 0.217

Bottom line is that I am exhausting all other options before I move to the next step which is the mirrors. I really appreciate any and all assistance.
This Forum has been quite a lifesaver!

 

[LaserApprentice]

Ok so with cutting conditions listed.
Its not cutting all the way through.
Also when it goes to cut out part molten metal
bubbles up to the surface sealing the cut and
causing interference with my nozzle.
I did forget add I am using the 7.5" lens
with the 1.4 Double Nozzle. Centering is almost perfect.

 

[LASERNINJA]

1/2" is pretty tricky for some reason. I believe you're on the right track though.

If I were you, I'd get comfortable with 1/4", then 3/8" before you jump into 1/2.

What I mean is those materials have the same setup just different feed rates. 110, 70, and 40 respectfully (45 is a bit fast for an old machine).

With a good, clean, 7.5" lens, move the focus increments of 0.04" up and down. Don't be afraid of going 0.200 in either direction from where u r now.

I tell people it's like being a little kid on the sidewalk killing bugs with a magnifying glass. Kids don't know which way to move the lens, they just do it till there is carnage. Same principle applies here. There is now magic number that someone can tell you, you just have to look for the acceptable range your self.

 

[LaserApprentice]

LASERNINJA,

First of all thank you for the encouragement. I tend to do very well with 1/4 and under and machine cuts like butter through those thicknesses. I do have a 2110 Alarm (Oscillator Internal Mirror Cleaning) which I was finally able to schedule a tech and now parts are on order. To be completely honest I would like to believe that the reason I am struggling with cutting this thickness is mainly starts with the material quality and from there it just snowballs into condition of optics and cutting conditions. Again, I appreciate your response and will keep keeping on! FYI this is what I have found to work the best at this time:

Feed: 36 Power: 3000 Freq: 700 Duty: 80 GasP: .06-.07

If I missed any other important parameter let me know.

 

[LaserApprentice]

Also about feed rate.

I adjust my feed rate based on lines in the cut. So if the cut direction is < and you have //// on your edge you would increase and if they were \\\\\\ you would decrease your feed rate. The reason for a feed rate in my original post is bc of my parameters the metal was holding a lot of heat. Also, cut was not being showing signs of slowing down the feed rate. I noticed today that my focal adjustments are not being reflected on my actual position for parameter B. I did a 0.0, -.280,& +.280 focal adjustment, 1 per part to compare and did not see a change. That's when I noticed my focal adjustment was not being implemented.

 

[LASERNINJA]

Excellent work!

That's what it takes... Patients, and making little changes, and being able to keep track of those changes and the effects they have.

There is a "bug" in amada software on the older machines. The software only reads line 1 of the cutting condition page. Regardless if u r on E4, E10 or whatever. Make changes there and see.

Also, that alarm you mentioned could be just a timer and not actually an indication of a problem with the machine. Most of the time, I clean every 6,000 hour of on time and replace every 12,000 hours.