HPDF optics for universal laser systems

[Roger McDowell]

Does anyone know if there is a generic version of the HPDF optics available for universal laser systems. I'm wondering if this would be worthwhile to cut mother of pearl.

[Kevin L. Waldron]

Heat from the lens will usually burn the Pearl.....(HPDF is hotter and closer to the material than a normal lens....We've cut a lot of pearl and it takes fair amount of power and have found that the longer the lens focus the better even though the beam is wider... We have two different Universals and have HPDF for both machines as well as a number of other lens.)

Blessings,

Kevin Waldron

[Dan Hintz]

Heat from the lens will usually burn the Pearl.....(HPDF is hotter and closer to the material than a normal lens....We've cut a lot of pearl and it takes fair amount of power and have found that the longer the lens focus the better even though the beam is wider... We have two different Universals and have HPDF for both machines as well as a number of other lens.)

Blessings,

Kevin Waldron

Closer to the material is irrelevant... it's not like the beam is a heating element from your oven, so distance makes zero difference.

HPDFO has a much higher power density, which means it will ablate material more quickly with a low HAZ, generally a good thing if you can ablate the material completely.

[Kevin L. Waldron]

Dan,

With all due respect........ playing the piano is harder than telling someone how to do it...... if you haven't done pearl..... don't think you have a clue........ in a lot of ways it's a lot like trying to laser a mirror on the reflective side. Heat causes the material to calcify/chalk and the sparks will burn the lens if your to near ..... ( We offered cut pearl for a number of years so we do have some experience in this area) The secret to pearl is multiple passes.... relatively fast with a large amount of power. Use different colors multiple times in Corel so as to make the machine go all the way through your file and start again. It is not uncommon to have 8-12 passes depending on the thickness...... inlay pocket will need to be .003 smaller .... at least for us on the male part. I lost interest in doing this is the reason we quit......very time consuming and different pearl required a gentle hand in knowing what to do.

Blessings,

kevin

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[Dan Hintz]

Kevin,

Perhaps your initial comments were not clear as to your actual intention, then? The way you wrote it, it suggested the beam itself was hotter... nothing in what you wrote suggested it was the lens in danger from radiant heat coming from the material being processed.

[John Noell]

I engrave a lot of pearl shells for a local black pearl farm. Trying to get a clean cut in whole shells is extremely difficult. Even relatively deep engraving often results in bad edges. However, the thin laminated pearl (and abalone) shell sheets do cut nicely (with care). I'd much rather cut wood/plastic/leather than try to cut pearl. And the pearl dust you get is really nasty abrasive stuff.