Everyone loves lasers it seems. How realistic is the idea of ripping a laser unit out of an old DVD-burner, and using it to heat, melt or etch? Is such a unit capable of enough power to melt the ABS/PE/PLA types of materials we're talking about here? If it can melt, we might have the possibility of a variant RepRap with a build tank, acting on layers or powder, SLS style. That method has its advantages to a lot of things we want to build. It does not require support structures, and improves resolution (to the grain size of the power). admittedly, it does require tanks, and sounds messy. Ian. [en.wikipedia.org] https://reprap.org/forum/read.php?1,22221,22221#msg-22221 Sat, 06 Jun 2026 00:06:27 -0400 Phorum 5.2.23 https://reprap.org/forum/read.php?1,22221,25681#msg-25681 https://reprap.org/forum/read.php?1,22221,25681#msg-25681
One essential point is the adhesion between the already fabbed body and the new placed tray/bit, then you adress the accuracy (step-resolution, tray-diameter or bit-size), material selection/changing, surface-finish and some other aspects defining the usability/seriousness of the fabbed output.

The area of interesting possibilities and methods is virtually unlimited - try it and/or make it!

Viktor]]> VDX General Thu, 30 Jul 2009 17:22:31 -0400 https://reprap.org/forum/read.php?1,22221,25680#msg-25680 https://reprap.org/forum/read.php?1,22221,25680#msg-25680
Surely if you are inducing currents to heat the media, the resulting EMF will blow the media away from inductor, and probably all the other particles of media...?]]> TheRuttmeister General Thu, 30 Jul 2009 17:19:27 -0400 https://reprap.org/forum/read.php?1,22221,25679#msg-25679 https://reprap.org/forum/read.php?1,22221,25679#msg-25679 -------------------------------------------------------
> ... unfortunatelly the TIG-plasmabeam will blow
> away the powder, so you can't build homogene trays
> or surfaces 8-)
>
> Another common method is blowing metallic powder
> through a plasmabeam so molten droplets will land
> and fuze to the surface ...
>
> Viktor

What about focussed induction heating?]]> annodomini2 General Thu, 30 Jul 2009 16:45:20 -0400 https://reprap.org/forum/read.php?1,22221,25643#msg-25643 https://reprap.org/forum/read.php?1,22221,25643#msg-25643
So try first with simpler/common methods and when this works, evolve further :D

Viktor]]> VDX General Thu, 30 Jul 2009 05:05:08 -0400 https://reprap.org/forum/read.php?1,22221,25642#msg-25642 https://reprap.org/forum/read.php?1,22221,25642#msg-25642
Would it work any better if you dropped the conducting tip down to touch the AL, so instead of an arc forming it instead acts like a resistance welder?]]> TheRuttmeister General Thu, 30 Jul 2009 03:56:52 -0400 https://reprap.org/forum/read.php?1,22221,25641#msg-25641 https://reprap.org/forum/read.php?1,22221,25641#msg-25641
Another common method is blowing metallic powder through a plasmabeam so molten droplets will land and fuze to the surface ...

Viktor]]> VDX General Thu, 30 Jul 2009 03:08:52 -0400 https://reprap.org/forum/read.php?1,22221,25639#msg-25639 https://reprap.org/forum/read.php?1,22221,25639#msg-25639 There would probably need to be some work done to get fine resolution, but TIG equipment should be much cheaper and safer than lasers.

And by using TIG kit... I esentially mean fitting a TIG tip in the same way as an extruder, and pumping enough current into a bed of powdered AL to get it to melt/sinter. Hopefully the AL itself, whether melted or still in the powder form would conduct enough for this to work.
It would still probably need protective gases and stuff like that.. and I doubt the resolution would be too great to begin with...

But is it an interesting thought? or just a silly idea?]]> TheRuttmeister General Thu, 30 Jul 2009 02:18:40 -0400 https://reprap.org/forum/read.php?1,22221,22607#msg-22607 https://reprap.org/forum/read.php?1,22221,22607#msg-22607 Corwin General Thu, 02 Apr 2009 12:46:55 -0400 https://reprap.org/forum/read.php?1,22221,22604#msg-22604 https://reprap.org/forum/read.php?1,22221,22604#msg-22604
Typical sintering/soldering CO2-lasers with 5 to 20 Watts power will have focus diameters of 0.5 to 0.2mm and the price in OEM is maybe the same, so they're much more effective ...]]> VDX General Thu, 02 Apr 2009 07:17:01 -0400 https://reprap.org/forum/read.php?1,22221,22602#msg-22602 https://reprap.org/forum/read.php?1,22221,22602#msg-22602 SnailRacer General Thu, 02 Apr 2009 06:44:34 -0400 https://reprap.org/forum/read.php?1,22221,22596#msg-22596 https://reprap.org/forum/read.php?1,22221,22596#msg-22596
You need a really sophisticated piece of software which handles online energy-measurement respective melting/sintering line-speed (energy dissipation over daytime and occasionally dimming through clouds)]]> VDX General Thu, 02 Apr 2009 03:39:09 -0400 https://reprap.org/forum/read.php?1,22221,22586#msg-22586 https://reprap.org/forum/read.php?1,22221,22586#msg-22586 R.J.Bowman General Wed, 01 Apr 2009 19:45:58 -0400 https://reprap.org/forum/read.php?1,22221,22541#msg-22541 https://reprap.org/forum/read.php?1,22221,22541#msg-22541 Gene Hacker General Mon, 30 Mar 2009 23:37:11 -0400 https://reprap.org/forum/read.php?1,22221,22535#msg-22535 https://reprap.org/forum/read.php?1,22221,22535#msg-22535
Aswome, good to hear. You were making some great progress for a while and then it kinda died before you had managed to release any of the plans. Looking forward to see what you come out with.]]> Colecoman1982 General Mon, 30 Mar 2009 16:36:06 -0400 https://reprap.org/forum/read.php?1,22221,22529#msg-22529 https://reprap.org/forum/read.php?1,22221,22529#msg-22529
Minor change of subject, but CandyFab is relaunching soon. :)]]> Windell Oskay General Mon, 30 Mar 2009 14:52:55 -0400 https://reprap.org/forum/read.php?1,22221,22321#msg-22321 https://reprap.org/forum/read.php?1,22221,22321#msg-22321
[www.corrosionspec.com]]]> colecoman1982 General Wed, 18 Mar 2009 13:55:18 -0400 https://reprap.org/forum/read.php?1,22221,22320#msg-22320 https://reprap.org/forum/read.php?1,22221,22320#msg-22320
[www.blastingaccessories.com]]]> Colecoman1982 General Wed, 18 Mar 2009 13:48:37 -0400 https://reprap.org/forum/read.php?1,22221,22319#msg-22319 https://reprap.org/forum/read.php?1,22221,22319#msg-22319
[www.greenhillsupply.com]

They seem to want $2.25 per pound for a 50 pound bag of 60 mesh and finer acrylic media. Not sure how fine these guys can go, but I've seen it listed at much finer grades. Using Wikipedia, I tracked down the density of acryilic as 1.19g per cubic centimeter. Assuming my math is right, that comes to $2.25 per ~381 cc or ~$0.10 per cubic inch. This seems to be a little less than 1/3 of the cost of the, above mentioned, plastic powder coat material.]]> Colecoman1982 General Wed, 18 Mar 2009 13:40:39 -0400 https://reprap.org/forum/read.php?1,22221,22307#msg-22307 https://reprap.org/forum/read.php?1,22221,22307#msg-22307
Now the objet printer is interesting it uses an inkjet process to deposit a photopolymer and then UV cures it. I wonder if you could do the same on an inkjet using a photopolymer "ink refill?"]]> ppeetteerr General Tue, 17 Mar 2009 21:25:25 -0400 https://reprap.org/forum/read.php?1,22221,22306#msg-22306 https://reprap.org/forum/read.php?1,22221,22306#msg-22306
Brian D]]> BDolge General Tue, 17 Mar 2009 21:12:40 -0400 https://reprap.org/forum/read.php?1,22221,22295#msg-22295 https://reprap.org/forum/read.php?1,22221,22295#msg-22295 cptwinder General Tue, 17 Mar 2009 17:11:11 -0400 https://reprap.org/forum/read.php?1,22221,22285#msg-22285 https://reprap.org/forum/read.php?1,22221,22285#msg-22285 ppeetteerr General Tue, 17 Mar 2009 16:16:23 -0400 https://reprap.org/forum/read.php?1,22221,22276#msg-22276 https://reprap.org/forum/read.php?1,22221,22276#msg-22276
One possible source for powdered plastic is in the form of blasting media (as in "sand" blasting). A number of companies make blasting media from thermoplastics such as PVC and can provide it in very fine grit form. You would have to buy in bags of at least 50lbs, but I don't remember it being too expensive. You might even be able to find it in dark colors that might improve the absorption of the light energy.]]> Colecoman1982 General Mon, 16 Mar 2009 17:40:39 -0400 https://reprap.org/forum/read.php?1,22221,22228#msg-22228 https://reprap.org/forum/read.php?1,22221,22228#msg-22228
One problem, though, is how to get the positioning system to move fast enough to take advantage of the higher resolution and get get stuff printed in reasonable amunts of time without resorting to an optical positioning system which is kind of expensive.

The other problem is getting polymer resins in fine powder form. Most resins come in 3 mm pellets. Powdered product is out there but buying it in something smaller than 20 kg bags could prove a little tricky.]]> Forrest Higgs General Sun, 15 Mar 2009 07:45:07 -0400 https://reprap.org/forum/read.php?1,22221,22221#msg-22221 https://reprap.org/forum/read.php?1,22221,22221#msg-22221
If it can melt, we might have the possibility of a variant RepRap with a build tank, acting on layers or powder, SLS style. That method has its advantages to a lot of things we want to build. It does not require support structures, and improves resolution (to the grain size of the power). admittedly, it does require tanks, and sounds messy.


Ian.


[en.wikipedia.org]]]> ian918m General Sun, 15 Mar 2009 04:17:57 -0400