is there any material that a laser will harden? like a powder into plastic?

[rich santana]

i was thinking about trying to use the laser as a 3D printer of sorts. i've seen some companys that 'print' in powder with a binder. ends up a tangible piece. i figured there HAS to be something out there..porceline, aluminum oxide, something?? any help?

[Rodne Gold]

A laser primarily works by Vaporising stuff , I think the power density is too high , but why not try with some of the stuff the 3d printers use.

[paul mott]

Inspired by the CandyFab project, I made this little bicycle from 3 layers of caster sugar. Made as a joke really but I never got around to trying finer particle materials such as Printer Toner etc.
One word of warning - many small particle materials are explosive and / or ignite easily.

Paul.


207028207027

[Dan Hintz]

One major issue you would have is creating a consistent Z-depth. The 3D printers screed a very thin layer of material over the freshly-lasered object, something you will need to do manually. Your layers will likely be quite variable in thickness, which also has the downside of either lasering too well (melting features, collapsing walls, etc.) or not enough (creating voids, walls that aren't attached, etc.).

[paul mott]

Dan,

The layers can easily be made consistent thickness using "frames". My attempt used 3 frames and of course the Z depth was adjusted for each frame.

(Perhaps you might like to take a look at the Candy Fab project and see how they have adjusted the Z axis downwards for each layer).

Paul.

[David Fairfield]

Its an interesting question I looked into a while back. I experimented with "embossing powder" which you can find in a craft store in the scrapbooking section, with the rubber stamp materials. Its a very fine plastic bead which melts and solidifies to make a raised embossed effect. I was not able to get consistent or usable results.

A side note, you can do a sort of 3d printing with the laser, by cutting topographic contours out of thin material and stacking them up. Alignment is assisted by cutting locator holes for dowels.

Dave

[Richard Rumancik]

I've pondered this question as well but so far haven't stumbled upon the right material. It's very likely there is something that will fuse rather than vaporize when heated; it is a matter of settings. One issue is keeping the material in place - you'd probably have to run without air assist but even the carriage motion during rastering moves the air a lot. As far as actually making a 3D object I don't think this approach is likely to be very promising. It might be possible to use it for 2.5 D raised areas on a flat surface. I was thinking of using it to create raised text on plaques similar to the thermographic printing that David alludes to - embossing powder is used on business cards and invitations. Some polymers foam up when heated and their volume increases - I was visualizing doing a shallow raster, filling with powder, and then re-rastering to make it rise above the surface. But I haven't found a material that will do this.

If your objective is a real 3D part then I would say that there are machines out there designed for this and the laser engraver is not a very suitable alternative.

A lot of 3D printing technology uses UV light rather than infrared (co2 laser) light to harden liquid polymers. But there just might be a material used on some of the laser-sintering type fabricators that would work. One problem is getting access to small quantities of material - if you know someone who has a laser-sintering type fabricator maybe you could get a few grams of material to experiment with. Keep in mind that these materials are quite expensive - the companies make money on the materials similar to the way ink of ink-jet printers is sold.

Keep us posted on your progress.

[Sotos Patistas]

Its an interesting question I looked into a while back. I experimented with "embossing powder" which you can find in a craft store in the scrapbooking section, with the rubber stamp materials. Its a very fine plastic bead which melts and solidifies to make a raised embossed effect. I was not able to get consistent or usable results.

A side note, you can do a sort of 3d printing with the laser, by cutting topographic contours out of thin material and stacking them up. Alignment is assisted by cutting locator holes for dowels.

Dave

Regarding your side note.....

Yup. :)

[rich santana]

i was kind of thinking like a thicker version of Cermark, perhaps maybe, sounds stupid but....volcanic ash is supposed to crystalize when hit with high forms of heat...
i know i sound like a quack, but i think just finding the right substance. and i was thinking the Z axis could just be programmed into the file....
i dont know, just have this cool laser and wanted to do more with it...

[Mark Conde]

Google Smoke Wood. It's a powder that can used as an infill. First you raster engrave. Then use smoke wood powder and the laser transforms the powder to a solid infill.
Not sure if this fits your needs or not, but you can get good results.

[Richard Rumancik]

Rich, if you Google "laser sintering" (sometimes called selective laser sintering) you might get some ideas as to what materials are currently used in 3D rapid-prototyping equipment. Laser sintering can include metals, but the lasers are probably have a lot more power than normally used for engraving. But perhaps you can find something that will fuse with a small laser engraver.

As to whetther you can adapt a laser engraver to make 3D parts - seems to me that that would be quite a major rework. Most of the engravers do not have a programmable z axis. You would also need to design some kind of delivery system for the material you wish to use. The firmware for laser engravers is not "open" so you really can't easily hack into the software. It sounds like a pretty major development project.

[Dan Hintz]

I cannot remember the name of the University offhand (in the US, if memory serves), but I know about 1-2 years ago one of them announced a number of materials they designed that were dirt cheap and were capable of high-resolution models. They were mostly ceramics. They starting working on the materials due to the high cost of what was currently available... though I found it ironic at the time they mentioned not having decided yet if they intend to "open-source" the recipes or sell the final product.

[Joel Ifill]

yes there are several industrial processes. Direct metal deposition, and selective laser sintering are the first two that come to mind. http://www.youtube.com/watch?v=SYbw1oSzPVA&feature=related http://www.youtube.com/watch?v=gLxve3ZOmvc I think the problem you'll find is in the hardware setup besides the laser. I.E most of these systems use loose powder or dedicated heads to deliver material into the beam. There's also the whole family of UV curative polymers that use a liquid resin that can be made solid. I think the problem there would be laser energy of the wrong wavelength but I've never dealt with those machines.

I'm sure there's some material out there that could be bound or sintered quite easily, but there's a lot more to think about besides just the laser part. in terms of having Z axis control to step your table down, and then having software that could slice your model at the right resolution.

I only know about these things as I during my day job I've done research and evaluated laser sintering and DMD processes for all sorts of tough metallurgical engineering problems. We have a few DMD systems and one of the plastic rapid prototype machines, but that uses an extrusion head similar to a real fine hot glue gun. I would look up various sintering compounds or maybe even some ceramics, but be prepared for a lot of headaches in other areas

[rich santana]

thanks for your answers all. i opted for the big budget and spent 5 bucks on ash from Mt. St. Helens. i spread it thin, but not super evenly across a piece of aluminum. i first vectored it at 100% power and .05 speed. it resulted in little shiny balls. they stayed together (each ball) and couldnt be broken down by fingering it against rough surface. that made me at least happy. then i rastered a circle at 100/5 and it actually made circle, that although it would rub apart, it stayed together enough to pick up. interesting thoughts. oh yeah, then i hit a pile of it with a propane torch and the torch wouldnt touch it.
i'll let all this bounce around in the brain for awhile. thanks again for all the comments. very inciteful, and i will do some more sintering searches.

[Martin Boekers]

I wonder if a powder material would work, if it would be possible to make say a box, fill it with powder, then place a sheet of glass over it
and focus through the glass when lasering would work?

[paul mott]

I wonder if a powder material would work, if it would be possible to make say a box, fill it with powder, then place a sheet of glass over it
and focus through the glass when lasering would work?

Not with a CO2 laser at 10.6um - You may perhaps focus through a disc of silicon though.

Paul.

[Dan Hintz]

I wonder if a powder material would work, if it would be possible to make say a box, fill it with powder, then place a sheet of glass over it
and focus through the glass when lasering would work?
Not with a CO2 laser... a fiber/YAG is what's you'd need for such a setup.

EDIT: Didn't realize there was a page 2 yet... Paul beat me to the punch.