LaserUser.com Forum (formerly RDWorksLab)

One other factor to consider with air-assist (besides the kind of air pump / compressor supplying the air) is the kind of nozzle you have on your laser. From what I understand (i.e. take this w/ a grain of salt because I haven't experimented with this personally), you really want a nozzle cone that directs the air very close to the surface that you're cutting. Among other things, this means that the ideal height of a nozzle cone is related to the focal length of the lens.

For example, if you have a nozzle that is perfect for a 1.5" (focal length) lens, then the nozzle tip will be (let's say) 1.25" from where the lens is mounted, or 0.25" above the surface of the wood you're cutting.
If you then put in a 4" (focal length) lens, that same nozzle will be 2.75" above the surface of the wood, resulting in very poor airflow into the cut.

Regards,

-Jeff

Jeff- the 4" lens goes in the other end of the lens tube, which makes it much closer to the nozzle of a 2" lens. There are many nozzles and some extensions to get the focus to what you desire. I use shims also so all my lenses have a 7mm focus gap.

Gene Uselman wrote: Fri Jul 16, 2021 Jeff- the 4" lens goes in the other end of the lens tube, which makes it much closer to the nozzle of a 2" lens. There are many nozzles and some extensions to get the focus to what you desire. I use shims also so all my lenses have a 7mm focus gap.

My lens tube has mount points for both 4" and 2" as well. And my current focus gap is 6mm.

I got the compressor hooked back up to the machine today. Much cleaner cuts so far, and the water trap is working great. And so far I've managed to not destroy my last lens haha. I still want to know how the compressor contributed to that.... but hopefully it was a one-off. I ended up ordering a half dozen new lenses from cloud ray lasers with expedited shipping and should have them mid-week... so running out of lenses wont be on the radar again

Learn something new every day in this job

Hi

Pretty new to this but it may be a case of news eyes looking at things as I've been going through a steep learning curve with a 2nd hand machine.
As part of the learning for the machine its demonstrated some odd behavior which has led me to this amazing forum and all the research.

1st thing i noticed in your post is that you stated "85%" power .. do you have an analogue milliamp meter installed to see what the true output is of the machine ?

85% power is the current from power supply not the capability of the laser. You might be putting 110% power through the laser as the power supply could be more powerful that the tube installed,.
Not sure how expensive or clever you cutter is but the rule of thumb that i have learnt is if your running the cutter at much more that 65% power you'll be killing the tube and shortening its life span.

This will result in drops in power from the tube during a cutting session so a power IE 50% on 4mm ply would cut like butter at minute 3 but at 7 minutes not be cutting half the depth... It will also change the profile of the beam.

So check vid s on youtube about Millamp meters and the output of laser to make sure its set right .. From what i have read so far much past 60-65% you only get fractionally more cutting power but reduce the life VERY quickly.. My money is on getting a new tube.


Watch the Russ's vids the ones talking about tube failing .to see if your symptoms remind you of what your getting ..
https://www.youtube.com/watch?v=JfRpa9Y5Woc


I am newbie so if I'm wide of the mark do excuse me !

Good Luck

Andy