I know, I know… I don’t have a MOPA, but can I still engrave like brass coins with a logo on it with my JPT 50w Fiber?
Never have done deep engraving as well. Not even really sure where to start with the logo either. I mean if you have a logo, how do you turn a flat piece of line art into something with depth?
I’ll find some vids on the YT, but they usually just show the final results. I can’t spend an hour on 1 coin either. I guess that depends on speed, power, freq and depth of the engraving.
Send something to view or read about if if I can actually do it.
Thanks… I believe this could be a revenue stream with a couple of my customers on the gulf coast. I have to find some vids on how to create or laser away material to get the depth. I don’t need a lot of depth, but some.
I think they are using a converter to make .stl files, a multi layer/ multi power type file. I don’t know anything about it other then from reading their posts,
If you have a 3d stl object file you can use stt2png and convert it to a grayscale. With a fiber you can select an image mode of 3dslice and it will create a layer for every level in the grayscale… this probably explains it better than I.
This is from the galvo beta area, so I have to cut/paste it… as most don’t have access…
This is from Oz on how 3dslice works.
With 3D Slice, each pass is thresholded to the current threshold value, and the result is run as a 1-bit image. If you use 256 passes you get exactly one pass per gray-level in the image. Every pixel at or below brightness 255 for the first pass, every pixel at or below 254, then 253, and so on.
If you choose 128 passes, you get every pixel at or below 254 for the first pass, then 252, then …
It “clusters” the layers together into batches if you use fewer than 256 passes, and will duplicate some layers (with even spacing) if you use more than 256. 384 passes would duplicate every 2nd layer. 512 passes would duplicate every layer.
All very interesting. Yeah, I can’t devote 1/2 hour of time to a coin that a reseller might want to charge a customer 5.00 for. I was thinking of how to create another revenue stream with my customers on the Gulf.
Hey Jack. All I have is an image of the customer’s logo. I have in Adobe Illustrator, and I have it in LB, that I’ve been using for the stuff.
I do intend on watching the vids though, and try to figure this out. It might be something that I can sell to, lets say the student body at a school or something.
All of them took over 2 hours each… such is life… there are some changes I made to speed things up, but it still takes lots of time to remove that much material… boring to sit there and watch the same thing over and over…
If I try to get more material out per pass, it seems to leave the brass with discoloration…
3D Slice is only available with a fiber… so your device, in all likelihood, is set for one of your other lasers…
Never tried that work path… can you explain in more detail how you do this?
From the photo, I agree, but it was engraved pretty well then I did a pass to blacken the unengraved area. Viewing angle makes in look rather deceiving from reality. You can easily feel it.
I’ve never found a good cleanup pass for these coins… if you know of one, pleas let me know…
I’ve dropped the power increased the frequency, interval and q-pulse… Never comes out shiny.
I have multiple lenses and I find that makes a rather large difference in your reslts with setting from a shorter or longer lens…
Don’t, hoping you did. Brass likes to be a bit difficult. I don’t do coins in brass, but if I did they would probably go into the pin tumbler or the vibratory cleaner afterwards. Ultrasonic cleaner might be even better.
The coins are not dirty… I can see it with the microscope that it’s the texture… varies with frequency/q-pulse… it’s pretty sensitive to too much power it goes from ok to dark rather quickly…
A bit off topic and if we want to discuss it further, maybe we can move it…
I had a couple questions about what the specification state and what my JPT MOPA will actually do…
This says adjustable frequency range is 40 - 4000 kHz…
I’ve looked that over, I have same or similar. zoom in and “Adjustable says 1-4000”, and the line above that says “Full” full power 40-4000, both specs agree with the threshold frequency chart. Full power from 200-500 pulse from 40KHZ
Anything shorter then 200 pulse the frequency needs to go up to achieve full power. I’m no expert but that’s how I read it.
I’m not smart enough to fully get the 3rd chart, but it appears to show the peak of the pulse no where near the center of the pulse by varying degrees except around the 80ns mark, but I’ve a bit of a color handicap so not quite sure. Do you think 0 on the t/ns scale is also the peak of the frequency waveform? Or is the peak of the pulse the center of the frequency waveform?
I think maybe you aren’t looking at it from the right angle…
A fiber is pumped up by (usually multiple) dpssl into the surrounding fiber area, then another dpssl fires down the fiber center allowing it to discharge very rapidly… Have a very nice diagram
It’s incredibly fast getting to it’s peak, but it takes time to dump the rest of the energy… so the peak is fast then it slows as the energy in the fiber drains…
I’m not that great at this level of explanation… However Russ Sadler has a video that shows how these fiber lasers operate at a pretty low level, but still comprehensible by laymen like me… about 32 minutes into the video… It’s about co2 and fiber… but the fiber part was a good presentation of the types.
Great video, thanks. Watched it twice.
One thing I noticed is his last chart the t/ns 0 is at the far left, where the chart above the zero is 250 ns to the right. Total duration of the longest pulse is about 350 +/-, where we are 500+/-. He had a 20W, must be a smaller pulse range then our 60W
