I want to burn the asshairs off my cat from 10 feet away, please help

[Insecure Sockets Layer]

Not really, but close. :crackup:

Hi!

I am attempting to construct a so called "Sub Surface Laser Engraving" (world famous for shitty monochromatic 3d pointillism) prototype machine for plastics and call it "Sub Surface Laser Beam Micro Machining".

and I am here specifically to rake in all y'all's advices on constructing the light source.

Wattage:

to be even more precise, I wanted to ask if any of you have a chart or an excel sheet or something that can help me find the diode or technology with the highest wattage per dollar. However, I want to reach a target of 10-40W, so I presumably wouldn't get very far with 5mW diodes


Wavelength:

Between approx 400 and 1050 nm.

Here, for example, is the transmittance spectrum for polycarbonate. (from wikipedia). For SSLBMM, we need relatively high transmittance.

Operation:

Can be pulsed or intermittent if continuous is not possible.

I was thinking I could arrange multiple diodes on a dome assembly with a common focal point and collimate them, redirect the beam through the gantry and finally have a precision focusing assembly as a printhead - so it doesn't really matter if the light source is clunky.

Purpose:

While this is not the primary goal, a derivative of the technology I want to test may eventually lead to pantaloons that completely eliminate swamp ass while still keeping your butt toasty, or semimagical waterproof boots that only let water in, but not out. (if you would want that, I don't know if you would want that.)

Research so far:

CO2 laser @ 0.1Wp$ (can not use because the wavelength is too long)

homebrew HeNe laser @ 0.02Wp$
808nm 500mW @ 0.05Wp$
DTR's NUBM44 @ 0.06Wp$

What are your guyses thoughts? currently I'm eyeballing the NUBM44. :thinking:

TeaLDeeR:

Nice to meet ya and how are y'all doing on this fine day? :beer:

 

[diachi]

Feel free to try it with CW diode lasers but I don't think you'll have much luck (Read: I'm almost certain you won't have much luck). Simply pulsing CW diode lasers won't make it work either - they use Q-Switched lasers in the commercial machines, those can achieve much higher peak powers (10s to 100s of kilowatts with pulse durations measured in the 10s to 100s of nanoseconds.) - which is required for this type of engraving to work. There's a reason commercial SSLE machines cost tens of thousands of dollars and more. The laser is only one part of that large cost...

If I had to pick I'd go with fiber coupled 808nm diodes, you can gets lots of power, it comes out an a nice homogeneous beam (Easy to focus to a small, clean spot) and you can run fiber direct to your print head which is much more convenient. Those are relatively cheap (Usually still $XXX, even as used/surplus), you can even find them used/surplus on eBay fairly frequently. You still need to figure out how to quickly and accurately focus it to different points in the Z axis, while also moving the beam in the X&Y axes. Again, even if you pulse a diode, you're not going to reach the power levels required.

Not sure why you bothered mentioning the $/W value for HeNe seeing as they only go up to a few 10s of mWs at best. Biggest one I've ever seen was 30-40mW and 4ft long.

TL;DR: There's a reason SSLE machines are expensive. Feel free to experiment but don't get you hopes up too high. You need high peak powers, thus something with a Q-switch.

 

[Encap]

TL;DR: There's a reason SSLE machines are expensive. Feel free to experiment but don't get you hopes up too high. You need high peak powers, thus something with a Q-switch.

Exactly Diachi -- an SSLE machine is not an easy to accomplish, low cost, home built toy.

Insecure Socket Layer:
Looks like even used SSLE machine are $10,000 and up.

Before you get too far out on a limb, ou might want to speak with an SSLE consultant and find out if what you are considering to do is even viable and what costs might be---no need to reinvent the wheel ---SSLE is well known since the 1990s

Here is one guy who knows SSLE glass work: Subsurface Laser Engraving - Best Glass Paints for the Glassware Industry | OrmoSol

He says: " As a consultant for 3D subsurface laser engraving I help companies to make the right choice. After all there is a lot of money involved. 3D laser engraving machine prices range from 20,000 usd up to 500,000 usd.

The choice of the machine is not only about the budget, it is also about what products a company wants to make. Are you into corporate gifts and 3D crystal awards or do you want to have a shop in a mall producing personalized items on the spot? If you produce corporate gifts what will be the quantities you produce? What is a good supplier of optical glass blocks? Are you thinking about glass signs, glass furniture or architectural applications?
Buying a subsurface laser engraving machine involves even more. What spare parts do you need to have on stock, which supplier has a good service, how can you learn to do some maintenance and troubleshooting? What are the power supply requirements? How to laser a 3D model into a crystal ball? Is there any difference between a 3D crystal laser engraving machine and a subsurface laser engraving machine?


All these questions have to be answered before you buy a machine. To help companies making the right choice and avoid disappointments, I act as an independent consultant, not connected to any supplier. With the knowledge gained over the years, from 1998 until today, I can help you to make the right decisions and start up as smooth and quick as possible. This is very cost effective in the end!"

contact: Contact Us - Best Glass Paints for the Glassware Industry | OrmoSol

:can:

 

[Insecure Sockets Layer]

Hi!

Feel free to try it with CW diode lasers but I don't think you'll have much luck (10s to 100s of kilowatts)

The thing is, I don't actually need to break down the molecular structure with the laser alone. Evaporating or burning it should be enough.

If you are concerned about the fact that even a powerful laser is not very efficient (because well, the work piece is transparent) for a proof of concept it would suffice if I mated a dark plastic plate to a transparent one and work in 2d if it doesn't work at all.


I mentioned hene because it has an acceptable frequency and I (probably wrongly) assumed that it was scaleable



I'm looking at the 808 more in depth now. I'm assuming you recommended it because it's a staple product and thus easier to find

 

[Insecure Sockets Layer]

You miht want to speak with an SSLE consultant .

Here is one guy who knows SSLE glass work: Subsurface Laser Engraving - Best Glass Paints for the Glassware Industry | OrmoSol

He says: " As a consultant for 3D subsurface laser engraving I help companies to make the right choice. After all there is a lot of money involved. 3D laser engraving machine prices range from 20,000 usd up to 500,000 usd.


:can:

Yeah I've been on his site yesterday I think. it looks like it hasn't been updated since 1999, so I didn't write him yet. (although this seems to be a common theme in the laser community, no offense pls )

but I don't want to engrave glass. I want to use a really wide beam angle (up to 45-50° incident) on possibly dyed polymer sheets.

BUT!

I will write him. promise.

 

[diachi]

Hi!

The thing is, I don't actually need to break down the molecular structure with the laser alone. Evaporating or burning it should be enough.

If you are concerned about the fact that even a powerful laser is not very efficient (because well, the work piece is transparent) for a proof of concept it would suffice if I mated a dark plastic plate to a transparent one and work in 2d if it doesn't work at all.


I mentioned hene because it has an acceptable frequency and I (probably wrongly) assumed that it was scaleable



I'm looking at the 808 more in depth now. I'm assuming you recommended it because it's a staple product and thus easier to find

Yes, but it's very difficult to evaporate or burn a material that only absorbs a smaller percentage of the beam. You need real high power density, so that the fraction that is absorbed is still a lot of power. It's easier with plastics because they don't conduct that heat away as quickly as glass and such, and also have lower melting/boiling/ignition temperatures. That said, you still need LOTS of power over a short pulse in a very small spot. Energy density is important too. What kind of spot size are you aiming for?

That might work with a 2D setup and 2 layers, one of which is black. What are you trying to achieve? It may be easier to come up with a solution if we know more about your project and possible budget.

808nm is a good choice if you need lots of power for a reasonable price, it's already used in lots of industrial processes including pumping other lasers. Lots of fiber coupled options available too which is useful in lots of applications. 808nm diode lasers are also one of the most efficient types of diode lasers.

 

[Encap]

Yeah I've been on his site yesterday I think. it looks like it hasn't been updated since 1999, so I didn't write him yet. (although this seems to be a common theme in the laser community, no offense pls )

but I don't want to engrave glass. I want to use a really wide beam angle (up to 45-50° incident) on possibly dyed polymer sheets.

BUT!

I will write him. promise.

From what I can see glass is the prefered material for SSLE to work well.

You might want to check out: http://www.vestamid.com/sites/lists/PP-HP/Documents/Polymers-Lasers-EN.pdf

They say: "3D motifs can be laser-engraved in normal, commercially
available acrylic glass, but resolution and brilliance are significantly poorer than in silicate glass. The poor quality of sub-surface laser engraving of ordinary polycarbonate has so far prevented the use of acrylic glass for this purpose."

However they have developed and nanomodified polycarbonate that make a good result possible ---they say: "To make colorless, (highly) transparent polymers laser-markable and sub-surface engravable, nanoscale laser absorbers
are required with a very narrow particle-size distribution and highly homogeneous distribution of the nanoabsorbers.
Only in this way can excellent high-resolution markings with good contrast be achieved. These nanoabsorbers can be
adjusted for the laser wavelength required.
For deep lasering, the surface of the object on the side where the laser beam penetrates is also required to be perfectly
plane. If, for example, the surface is waved on a macroscopic scale, the text obtained is also visibly wavy."

 

[Insecure Sockets Layer]

What are you trying to achieve? It may be easier to come up with a solution if we know more about your project and possible budget.

I'm trying to etch microchannels into the plastic to serve as a delivery and mixing method for a "lab on a chip" type thing.

i'd say the maximum budget is $1000, but I'd much rather do it for 100

To make colorless, (highly) transparent polymers laser-markable and sub-surface engravable, nanoscale laser absorbers
are required with a very narrow particle-size distribution and highly homogeneous distribution of the nanoabsorbers.

I hope that I don't need to carbonize (split up the molecules) to achieve my result. And foaming shouldnt happen (which requires an immense amount of energy, because you have pressures that approach infinity) because there is always an outlet to either atmosphere or vacuum (i am considering machining it in vacuum if tests indicate that the plastic takes too long to vent)

as for the "nanoabsorbers" I considered the option of using appropriate dye in the polymer and a very wide angle beam. the resolution I will get is up to the gods.

sounds solid so far?

btw thank you guys for taking your time to look at and vet this project. it's really appreciated!

 

[steve001]

I suspect the optics required to do this type of engraving are many and expensive. I doubt you could build this machine for $100.

 

[diachi]

I suspect the optics required to do this type of engraving are many and expensive. I doubt you could build this machine for $100.

I don't see how you'd do it for even $1000. I don't even know if it'd work...

It may be a good idea to test the concept on a commercial machine if you haven't already.

 

[Insecure Sockets Layer]

I suspect the optics required to do this type of engraving are many and expensive. I doubt you could build this machine for $100.

1x large collimating lens

1x large, maybe fresnel, focusing lens

100x (hyperbole, or is it?) diode focusing lens, maybe fiber optic kits, heat buffers

1x mounting scaffold

could get tight.

 

[Insecure Sockets Layer]

I don't see how you'd do it for even $1000. I don't even know if it'd work...

It may be a good idea to test the concept on a commercial machine if you haven't already.

Well, good thing I intend to try ;D

I considered doing it with a classical crystal engraving machine, but doing what I want to do requires a significantly higher load on the machine than doing graphics (they only insert tiny dots, I need to remove material.) Additionally, the workflow and the software involved would likely need to be modified.

The advantage of having my own machine is that I can play around with materials and tweak it.

However, I will ask around.

 

[Benm]

If you want to do any sub-surface work i'd reckon you'd need a well defined collimation point somewhere below the surface. Multimode lasers will not be your friends in such attempts.

 

[Insecure Sockets Layer]

If you want to do any sub-surface work i'd reckon you'd need a well defined collimation point somewhere below the surface. Multimode lasers will not be your friends in such attempts.

What's a collimation point?

I suppose I could insert an absorptive collimator after the collimating lens to further clean up the beam if necessary, and if really really necessary split and prefocus the different wavelengths or filter them out completely...

 

[Encap]

What's a collimation point?

I suppose I could insert an absorptive collimator after the collimating lens to further clean up the beam if necessary, and if really really necessary split and prefocus the different wavelengths or filter them out completely...

From what you have been indicating and saying I would guess it isn't going to happen unless you know of or or can find a shop that can do exactly what you want. If not there probably are good technical reasons why it isn't being or can't be done. I think what you imagine can do the job , can't --SSLE and lasers do not work the way you imagine they do.

Check out what is being done and can be done in the real world before you waste a lot of money and find some experienced and expert advice--people that do what you want to do, if they exist.

THe best advices o far is Diachi's comment:

I don't see how you'd do it for even $1000. I don't even know if it'd work...It may be a good idea to test the concept on a commercial machine if you haven't already.

In any case, good luck in finding a solution.

 

[steve001]

What's a collimation point?

I suppose I could insert an absorptive collimator after the collimating lens to further clean up the beam if necessary, and if really really necessary split and prefocus the different wavelengths or filter them out completely...

I think that means point of focus.