Laser Sintering Patent to Expire?

Is it true that the laser sintering patent will expire in February 2014, which will allow open source 3D printers to be made that can make things from more materials, including metal and ceramic?

Maybe...

You can make a laser sintering printer right now if you want to:
SLS Wax Printer (prints in wax)
Focus SLS Printer (prints in nylon-like PA2201)

and other folks are working on systems that can do metal:
Metalbot.org

I'm not sure patents are the main thing holding people back, in this case.

Here is what dragonator said about his Focus SLS printer on its Thingiverse page:

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dragonator
Nobody has gone into SLS desktop printers because it is unknown, really hard and dangerous (high powered lasers). Powder management could be a health issue, but I think it is mainly this: no real prospect for usable parts in experimental printers and too many unknowns. (for SLS and 3DP)

I haven't had a single usable part, just some experiments. Everything I do is completely unknown.

I am currently planning to convert Focus to 3DP printer, because I need a break from the hell that is SLS printing. I need to rethink SLS before I will continue with that.

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dragonator
SLS is one of the most versatile techniques, but this is about the hardware available. I simply miss too many things on Focus (heated buildbox, scanner, inert gas chamber) to yield any results. The laser is too low powered and the carriage is too slow.

I cannot print in SLS because I have huge amounts of shrink, enough to displace previous layers and enough to warp a 3mm part 1mm. All hardware needed to have less shrink is not and will not be available due to the used hardware on focus. To properly sinter, I need scanners with galvo's, High powered laser that can melt without additives to the powder, heated buildbox and chamber.

At this point of the project it is way easier to convert Focus to 3DP. All hardware necessary is already there. I might design an SLS specific printer one day, but that is a €3000 project, and I lack proper funding and time for that.

I wish you luck with the SLS printer. It helps me sometimes set a project aside and work on something else while my subconscious works out a difficult issue. Perhaps while you convert Focus to 3DP your subconscious will provide an insight for SLS.

The €3000 isn't a huge amount, maybe a few hundred people would donate €5, if you have a convincing plan and ask for donations.

What advantages are you expecting from laser sintering?

I think the problem with laser sintering is that it does not scale down well, that is for $30,000 machine it has advantages and the cost can be absorbed into the price, but for a $2000 machine it is just a lot of problems, and a cheap solution is not going to be much better accuracy or faster than a good FFF printer. Lasers require some careful engineering, and can be horribly expensive especially for metal. Micro-fine powders need to be obtained from somewhere, and are just really nasty to handle.

I think uv resin printers are a more promising avenue in the near term, you don't need high power laser and handling liquids is much easier.

bobc Wrote:
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> Micro-fine powders need to
> be obtained from somewhere

[www.filastruder.com]

Price compare - 3D printers lists well over a hundred FFF printers with various features and prices. Plastic is a really good material for many things, but it is not the only material. The competition in FFF printers will eliminate some of the 100+, and some of them will work on a printer for another material.

Some things must be made of various metals and ceramics. Scientists have developed a nano-scale 3D printer. They also have developed plastics that conduct electricity, plastic transistors, and other devices now made from silicon, metal and ceramics. In the not too distant future, I expect electronic devices will be made without silicon, metal and ceramics.

I am curious about what open source manufacturing machines will be developed next. And, I think one possibility is develop additional types of manufacturing processes, including molding and robotic assembly. After all, continuous extrusion of monofilament is already on the agenda. I have seen suggestions about making electronic devices, and no doubt there are others. Someone is at least thinking of how to make all the parts necessary for a RepRap, and I expect it will be done eventually, probably fast enough to make our heads spin.

Quote
bobc
Micro-fine powders ... are just really nasty to handle.

This is true. A lot of people underestimate this problem. I worked with a powder-based printer, and I liked it, but the powder got absolutely everywhere. Everything in the same room as the printer got coated with powder, it would track out into the rest of the building... well, you get the idea. Not something your housemates are going to let you set up in the laundry room.

An entirely integrated robotic system that handles the parts and cleans them off, complete with airlocks and other contraptions might work...

Quote
EdEarl
Someone is at least thinking of how to make all the parts necessary for a RepRap, and I expect it will be done eventually, probably fast enough to make our heads spin.

I hope so! But at this rate it might take a while. Lot's of people want to make printers. Hardly anyone cares if they self-replicate.

Quote
EdEarl
Is it true that the laser sintering patent will expire in February 2014, which will allow open source 3D printers to be made that can make things from more materials, including metal and ceramic?

Patents are not the issue... in fact, as has been mentioned by Matt, a few people have built at least semi functional SLS printers. Here are some of the issues we face: [www.metalbot.org]

I think the patent you are referring to is currently held by the "IMPALA" project: [www.metalbot.org]

Building a SLS printer that can make parts in metal will be significantly harder than building one that just does plastics.

Powder ingress is on the (currently substantial) list .

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3D Metal Printing and more - visit [www.metalbot.org] !

I cannot access the metalbot site. I get this error:

403 - Permission Denied

You do not have permission to retrieve the URL or link you requested, /
Please inform the administrator of the referring page, (none) if you think this was a mistake.

is the link correct ?

thanks,
mihai

Do both links fail?

Here is a direct link to our forum which should work perfectly: www.metalbot.org/forum

We are in the process of overhauling the current site... sorry for the inconvenience! If it continues to give trouble please contact me via PM here or email: info@metalbot.org .

Edited 1 time(s). Last edit at 08/27/2013 03:11PM by Hazel1919.

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3D Metal Printing and more - visit [www.metalbot.org] !

both link failed ...

regards,
mihai

Both links work for me, if a bit slow loading.

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Help improve the RepRap wiki! Just click "Edit" in the top-right corner of the page and start typing. Anyone can edit the wiki!

Well, the only patent that really mattered, patent 4863538 also known as "the roller," expired in 2011.

There is one key difference between laser sintering machines produced by 3d systems and everyone else(pretty much just EOS). EOS uses a knife to spread a uniform layer of powder across the powder bed. This doesn't work that well and EOS only does so because of a patent dispute with 3d systems. So what 3d systems uses is a roller that counter-rotates across the powder bed. This is one of the key innovations that Deckard invented that transitioned laser sintering from making 'blobs' to making 'parts.'(Here's a nice history of SLS)

Even though the patent expired, not much seems to have changed. I'm pretty sure EOS still uses their knife edge system.

But if there are a bunch of laser sintering patents expiring, then I'd expect see some Chinese machines start to get sold in western markets. We have no idea what the Chinese are up to as far as additive manufacturing goes other than they don't follow our patents.



Powder is pretty messy stuff, it gets everywhere I used to work for a company doing mass manufacturing of Laser sintered parts. When you walked in the building you didn't so much smell the powder as taste it. Even with vacuuming around the machines and a negative pressure part removal area, it still got EVERYWHERE!

SLS is also very hard. The sintering process is quite sensitive to temperature. The slightest bit of convection in the build chamber can drastically decrease part quality. Having a heated bed also really helps quite a bit according to the math of sintering.

As far as the Focus 3d Printer goes, the parts it made actually look pretty good for first prints. Compared to the first SLS prints ever, they're damn good(see below). Warping could probably be eliminated if supports were fabricated in, just like in the DMLS process.



Speed will have to be improved, but using a cheap laser scanning system and a more powerful laser should solve this.

@bobc you can usually obtain cheap high grade powders from your local service bureau. Often times they'll sell you "overflow" powder that isn't quite up to spec. Contrary to popular belief, the powder doesn't recycle all that well, but if you're testing out your own laser sintering machine it should be fine.

I'd imagine you'd be able to get much better accuracy too.


@Hazel1919, the Impala project does not use SLS, it's using laser engineered net shaping(LENS).

I have to agree with Gene,
I used to work with SLS in the late 90's and its really messy. Cleaning out the machine, breaking out the parts from a block of powder which requires a blast chamber and compressed air. Sieving the powder back into the drums and adding a percentage of new powder. It floats in the air and covers everything.
Then you need a nitrogen filled build area or it all starts to burn, leaking nitrogen can kill you.
The whole build area including the already lasered portion and the powder ready to be added has to be heated to almost the melting point of whatever is being used. This is to take the strain off the laser, the powder is raised to almost melting point and the laser finishes off the last few degrees.

Maybe it will be possible to do this at home one day but I don't see the advantages over SLA or 3d printing using repraps. Maybe for printing metal SLS would be better but even that makes more mess. We hat to put the printed metal parts into a furnace after printing and then place pieces of metal next to the object in the furnace. When it heats up, the metal pieces are drawn into the printed metal structure which is not made of real metal but is a kind of resin/metal mixture. It's not something that most people could do at home even if they could manage to build the machine.

This is really technology for a fully equipped workshop.

Good luck to anyone who builds this though, it will be nice to see it on youtube. I heard the 1st prototype SLS machine was built inside an oven with a glass top filled with nitrogen. The laser sat on top of the oven and shot down to the powder. That might be a good place to start.

Edited 1 time(s). Last edit at 08/31/2013 04:47AM by mikefiatx19.