etching help

Sorry, I'm not familiar with Mazak codes, but-
When I'd etch/mark on material, depending on cutter path, I would see the machine slow way down from commanded feedrate. The machine/controller couldn't maintain a high feedrate through any kind of sharp corners or detailed geometry.
Unless there's some way to control 'effective power' according to actual feedrate, try reducing commanded feedrate and power, and experiment.

Rate of pulsing will affect the appearence. Try setting the pulse rate so you get one pulse per .005inch to .010 inch of travel. Peak power and duty cycle - don't know, but try an average power of 100-300 watts, and see what happens. Once you get a fairly uniform result, you can tune parameters for appearance.

(why pulse?) If power density is too low on the part surface, nothing happens. Pulsing is a way to get high enough power density to affect the surface, without putting so much power that you burn through.

cheers
Jay


Jay Maechtlen

I have Mazak TX-48 (1000W). I use the following to etch (5" FL and 0.060" tip.

%
O9000
(AIR ETCH)
G82P1Q1R1
M52
M32
M20
M22
G4X0
G82P600Q200R30F150
M52
M99
%

I had a similar problem on my 4kw Amada machine. The problem occured when switching from etching to cutting. I had a large reduction in power set for the etching. When it would go from cutting a part to etching the next, the machine was still using way too much power (couldn't drop power fast enough). I solved the problem by leaving the power level close to the cutting power, but reducing duty (and possibly frequency, I cannot recall) severely). It was then easily able to change from cutting to creating a consistent etch.

Alright,

First and foremost you shouldn't need any hyperpulse, superpulse, etc, etc. The only reason these are there is because in the past it was tough to pierce through thick materials with only 1500 Watts. Therefore, resonators use to spike the power up to 1.5X to 2x the actual power.

You can use normal pulsing in your machine by simply having less than 100% Duty cyles. Depending on the etching quality you are trying to achieve, you can use either nitrogen or oxygen. Oxygen will probably etch the material better with low power (P1500/Q1000/R15), and nitrogen will do better (on Stainless) with a bit more power.

Now, the first thing you should do is to etch everything first and cut later. Specially if you are using both oxygen (for etching) and nitrogen (for cutting). This can cause contamination on both and the etching quality suffering the most.

Your machine should be able to handle this without a hiss, like anything else, it's trial and error. Make your life easier, get the etching out of the way and then cut.

Thanks for all the input. I have always done my etching first then cut. Maybe I am looking for to much in my etch. How good does it get? Can you get etches to have a constant depth? Is it comon for the nozzel to plug up? Oh this is all mild steel I am playing with. No need for Nitro.

Have you tried etching with compressed shop air instead of pure O2? We had this problem and got great results with .2 bar shop air with appropriate etching power and feed for the material being etched. Pure O2 can burn too aggressively. We also run an etch line on the waste skeleton area of the sheet prior to every block of etching to purge the line of pure O2 or nitrogen so that the etching will be consistent.

Ok, another thing or two-
1- you can run the nozzle pretty high, and a pretty low gas pressure.
2. variations in depth will probably be due to varying speed- and that will be due to commanding a higher feedrate than the machine can perform on that contour.

Some controls have a way to control power according to actual feedrate. If you hhave that, it could help a lot. If not, then you just may not get a totally constant depth of etch.

When cutting into a sharp corner, the extra power mostly goes through the cut slot, and the material carries away some of the extra, and the gas flow also carries away some of the heat.
When etdching, ALL the power is there on the surface. If you can't control power (or pulse width, or pulse rate) according to speed, then maybe the best you can do is SLOW DOWN and adjust parameters to get a good result at that slow speed.
What speed and power are you currently using?

cheers
Jay

Jay Maechtlen

Sorry my computer took a dump andI have been down for some time...

My speed and power are G82P0050Q100R50M67F39.

sorry, I'm not familiar with the Mazak macros and commands.
What does that means in terms of:
feedrate in inches per minute?
cw power?
frequency?
duty cycle? (or is it pulse width?)
what feedrate does the machine actually maintain during the commanded contour?

regards
JAy

Jay Maechtlen

power is 50 watts, frequency is 100, duty is 50, and feed rate is 39 inches per min.

At 100 Hz, the dots should be about .007 inches apart, right?
Up the power and reduce duty to 5% or so-each pulse will make a notceable 'dot' on the material. The spacing of the dots will tell you how much the feedrate varies as it moves around the contour.

Some lasers don't 'like' running at very low powers, and aren't consistant when doing that.

Try 200-300 Watts, and 10% duty, see how it does. Once you get a better mark, you can up the frequency to smooth out the mark, but try the power and duty first.

Let us know what you see!
Regards
Jay


Jay Maechtlen