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DMLS -Direct Metal Laser Sintering- Build Steel Parts for CHEAP

Posted by Tim Ruffner 
Process

Utilizing the DMLS process, metal parts of the most complex geometries are built layer-by-layer (down to 20 microns) directly from 3D CAD data, automatically, without tooling. The parts have excellent mechanical properties, high detail resolution and exceptional surface quality. The process melts the metal powder entirely, creating a fine, homogenous structure.

Benefits

DMLS enables the formation of cavities and undercuts which, with conventional methods, can only be produced with great difficulty, if at all. Additionally, when a part needs to be tested and re-designed over and over, the lead time for receiving a traditionally tooled part can create a large bottleneck in the final production process. Previously, casting the part was the only traditional means of bypassing this process. However castings had limitations and depending on the functional needs of the prototype, a cast part could possibly fail if performance tests are desired on the prototype.

Now, GPI reduces the design phase timeline from weeks to days for the delivery of parts, allowing time for multiple redesigns and builds. Depending on size and geometries, in some cases the turnaround time for a part can be as little as a few hours. Furthermore, these parts can undergo functional testing in the environment for which they were designed. This technology opens up the ability for designers to imagine the impossible solution, because it is now possible with DMLS.

DMLS AND PROTOTYPING LINK CLICK HERE TO LEARN MORE
Sounds great. Now can you provide a link to your design for the home-built metal sintering system for hobbyists?
You can use DMLS to build parts for any home built projects in a cost effective manner. Let me give you an example.

A person creating a motorized pedal bike using a 5 HP briggs and stratton motor is almost finished with his home built project, however his crank shaft is using a bearing that is copper based and fell apart. DMLS makes the part in steel and all together as 1 part. So the bearings and the part are made together as a whole and it is a specialized part. Now he was able to make his part and finish his motorized pedal bike and can cruise around town.

That is just 1 idea, but other ideas pertaining to home-built projects would be Home Inventors who are coming up with an idea, DMLS technology is to help these inventors finish their projects and to start marketing it.

Another option would be 3-D printing...3D printing allows you to prototype the project before it is put into production.

Learn about 3d Printing by clicking here
VDX
Re: DMLS -Direct Metal Laser Sintering- Build Steel Parts for CHEAP
October 12, 2009 11:50AM
... bearings made from sinterted steel-powder spinning smiley sticking its tongue out
I do them bearings all the time from sintered powder, amazing I know, great product it is smiling smiley Technology has come so far !!

What types of prototype method is everyone currently using ?

I understand traditional CNC is easy for metal parts that are not highly geometric.
Re: DMLS -Direct Metal Laser Sintering- Build Steel Parts for CHEAP
October 28, 2009 09:24AM
Direct Metal Laser Sintering requires buildup of powder, layer by layer, followed by fusion with a laser.

In other words, it's a laser cutter with a powder bed. This should be hackable by combining an off-the-shelf laser cutter with Fab@home or even CandyFab technology. From there it's all about finding the right settings.

It may be necessary to work under a nitrogen or carbon dioxide atmosphere, as steel powder is highly flammable under the right conditions;

I've not seen an open hardware design for a laser etcher or cutter, but that would make me a happy fellow indeed. :-D
Re: DMLS -Direct Metal Laser Sintering- Build Steel Parts for CHEAP
October 29, 2009 03:18PM
I've not seen an open hardware design for a laser etcher or cutter, but that would make me a happy fellow indeed. :-D

Tim, would you be interested in helping us design one? It could be sort of how Adrian used his Stratasys FDM 3D printer to make RepRaps.

(I wonder how soon before commercial fabrication machines come with shrinkwrap licenses: BY OPENING THIS CARDBOARD BOX, YOU AGREE NOT TO USE THIS MACHINE TO MAKE OTHER FABRICATION MACHINES THAT SELF-REPLICATE!)
Re: DMLS -Direct Metal Laser Sintering- Build Steel Parts for CHEAP
October 29, 2009 04:58PM
LOL Sebastien. Or they're zoned like DVDs....
Hi,

I'm a French student studying the DMLS process and I'm very interesting in what are you saying, but I need some help.

I know that DMLS machines tend to be hard to set and position work accuratly. There are two main issues associated with accurate work location on DMLS machines:

* The build platforms upon which the metal is sintered do not have any form of positional location to the main build chamber within the sintering machine.

*The datum point for the laser in not known. The laser has a home position that is based on the positioning of the mirrors that reflect the laser beam into the build chamber.

So I'm looking for a procedure to allow the datum position of the laser to be measured and thereby related to the position of the fixture.

Thank you
VDX
Re: DMLS -Direct Metal Laser Sintering- Build Steel Parts for CHEAP
November 12, 2009 12:46AM
... recently i've got a 50Watt Ytterbium-fibre-laser which is capable of cutting thin steelplates or melting metal-powder (or other materials too).

My plans are to place the optic head along my CNC-millhead, so i have a defined reference-position of the laser spot when homing the machine.

First i'm working on cutting and engraving, but the next step is a feeding support for powder, so i can test with direct powder sintering - for metal-powder i'll need inert gas, so this is a more complicated process, but i have some samples of glass- and rock-spheres around 0.05 and 0.1mm diameter, what's good to feed/apply and should be melting/sintering without inert gas too ...

Viktor
VDX
Re: DMLS -Direct Metal Laser Sintering- Build Steel Parts for CHEAP
November 13, 2009 12:29AM
... for getting a feeling of the limits of the laser i made some tests and asked an application guy from the manufacturer - with a simple focus-lens i've got a spotsize around 30 microns ... with a 'beam-widener' and 1:5 enhancing the beam diameter befor the focus-lens i've got a spotsize between 10-15 microns (couldn't measure it better with my equipment at home) ... and with optimal adjustment i should get a minimum focussize between 5-4 microns smileys with beer

The only 'problem' now - my powders aren't fine enough to test the limits eye rolling smiley

I have black (very good absorpting) rock-spheres between 100-200 microns, glass-spheres around 50 microns and three grades iron-spheres around 50, 10 and 5 microns (but here i need inert gas eye rolling smiley).

So my minimal sintering accuracy is actually defined by the size of the spheres - here i'll have to find finer granulities ...

Viktor
Re: DMLS -Direct Metal Laser Sintering- Build Steel Parts for CHEAP
November 13, 2009 01:34AM
VDX Wrote:
-------------------------------------------------------
(but here i need inert gas eye rolling smiley).
>
>
> Viktor

For trials, little bottles of CO2 or CO2/Argon used by small welders as a suggestion
Re: DMLS -Direct Metal Laser Sintering- Build Steel Parts for CHEAP
November 13, 2009 01:37AM
Viktor,
Where did you get the laser from and how much was it?

What sort of lenses do you use?
Chris


[www.hydraraptor.blogspot.com]
VDX
Re: DMLS -Direct Metal Laser Sintering- Build Steel Parts for CHEAP
November 13, 2009 01:55AM
Hi Chris,

... i've got the laser for free - we're a small community across Germany where we can exchange help, spare parts and ideas for our different DIY-developments grinning smiley

The lenses are common ZnSe-lenses - either as single focussing lens or as 'beam-widener'-telescope ...

Viktor
VDX
Re: DMLS -Direct Metal Laser Sintering- Build Steel Parts for CHEAP
November 13, 2009 02:01AM
annodomini2 Wrote:
> For trials, little bottles of CO2 or CO2/Argon
> used by small welders as a suggestion

... i have have all sorts of gasses on my daywork, but for realizing this at home too i'll need some more time - actually i'm building an exhausting-system for the laser, usable too for soldering and such, so my children (9 and 11 years old) can start with their own handicraft ...

Viktor
Re: DMLS -Direct Metal Laser Sintering- Build Steel Parts for CHEAP
November 24, 2009 01:23AM
Don't use CO2! You'll end up with a brittle mess. You probably didn't need me to tell you that though. :-)

I'm quite excited that you're working on this. I'll be keeping an eye out for where this goes!
VDX
Re: DMLS -Direct Metal Laser Sintering- Build Steel Parts for CHEAP
November 24, 2009 01:47AM
Hi Sam,

... yes, i know, it's the Carbon changing chemistry - but sometimes a specificied CO2-Argon-Mixture can result in interesting steel-/alloy-properties grinning smiley

My intention is to use Argon, as it's common and therefor not so expensive like other inert gases.

Recently i tested in air with low power DC and the black 0.1mm-rock-spheres ... they're highly absorptive, so melting wasn't a problem.

But with DC it's even below 2 Watts to much power for micro-sintering - i produced remelted much smaller microspheres (nanospheres?) from 50 microns down to sub-microns eye popping smiley ... or received bigger molten 'blobs' with defocussing instead of agglomerating the spheres to a solid surface.

Here i have to adjust the power- and timing settings so i'll stop the laser when the single spheres are fluid, so they can fuse with their local neighbours in a range of maybe 50 microns around instead of evaporating and recondensing as 'nanospheres' winking smiley

Viktor
Vik: When I used to work in a coffee shop, we had a cream whipper that used little cartridges of compressed nitrogen. Check with a local catering supply company and see can you source some of these, they'd be perfect for single-use atmosphere conditioning!

If you couldn't get the right part to mate with the valve, you could just have a small linear actuator push the release inside the valve to let out the nitrogen.

Careful not to do this while holding the cartridge. Boyle's law and frozen fingers.
VDX
Re: DMLS -Direct Metal Laser Sintering- Build Steel Parts for CHEAP
November 25, 2009 03:13AM
Hi Cathal,

... don't worry, the gas-support is on the way smiling smiley

I have some pnematic/vacuum tools as valves, 2-/3-way-switches, connectors, tubes and such ... and found yesterday in our german CNC-forum some more festo-parts for switching and directing gas-flows, so now i can build some more really sophisticated setups for pure or mixed gases or vacuum.

The bottles aren't a problem too ... i'm a (the last years passive) scuba-diver and have some of the tools and assemblies for 200bar/7.5bar and in my daywork we order regularly 10l-bottles of different gases (2000l infill) or 50l-bottles of Nitrogen (5000l infill).

AFAIK a 10l-bottle of Argon isn't so expensive and i can refill some of the gases in smaller bottles like 0.5 litres for testing purposes.

It's only the lack of time realizing this all at home ... i have some other time-consumpting tasks (daywork and family) running in parallel, which have higher priority eye rolling smiley

Viktor
Sounds excellent! I'll look forward to seeing your results.
Good job you didn't take my advice in the meanwhile, because someone contacted me off-forum (he couldn't post here for some reason) pointing out that those cream frother cartridges use Nitrous Oxide, not nitrogen.

BIG difference!
VDX
Re: DMLS -Direct Metal Laser Sintering- Build Steel Parts for CHEAP
November 26, 2009 07:28AM
... "Nitrous Oxide", also known as "laughing gas", would have made my day grinning smiley

Viktor
Re: DMLS -Direct Metal Laser Sintering- Build Steel Parts for CHEAP
November 28, 2009 01:50AM
VDX Wrote:
-------------------------------------------------------
> ... "Nitrous Oxide", also known as "laughing gas",
> would have made my day grinning smiley
>
> Viktor


Save it for the car grinning smiley!
Accelerate Your Product to the Market with Rapid Prototyping :

This is one of 4 total blog posts that I currently have on typepad. I started with the first blog being Bring Your Invention or Idea to Life. From concept to development to design to production then finally marketing.

http://www.communitymarketing.typepad.com/my_weblog/2009/12/accelerate-your-product-to-market-with-rapid-prototyping.html

All I ask is you check it out, add a comment on the blog based on your experiences and you can also comment about my writing skills and content. Add what you can to the post as we all want to learn more about what you have utilized or want to for that matter.

http://www.communitymarketing.typepad.com/my_weblog/2009/12/accelerate-your-product-to-market-with-rapid-prototyping.html

Regards,
Tim Ruffner
tim@gpiprototype.com
I am very interested to see where this is going smiling smiley ...

DMLS unit uses a argon chamber, decompresses the chamber so all the oxygen is released. Oxygen levels must not exceed 7.

A YAG or Fiber Optic laser would be optimal.

Simple thompson bars can move the recoater arm and belts for each plate one for the built plate the either for the vat. Something like a stepper motor would work perfect.

I can see the machine working but the biggest hurdle being the software...and or hardware to recognize files to be printed.

You can check out some info over at GPI... They have spec sheets and what not posted on their website all about DMLS. GPI PROTOTYPE DIRECT METAL LASER SINTERING DMLS
A lot of people want to know the costs involved with producing a part using the DMLS machine in order to DIY. Be pretty bad ass to have a machine make your own parts to make another machine winking smiley

DMLS Blog about Direct Metal Laser Sintering Parts by GPI Prototype

Tim Ruffner
So I took all your comments into thought, edited the video and BAM here it is. I know it still might be a little cheesy, however you can tell we made some big changes. Here's the deal. If you can guess JUST 2 of the changes we made, I'll hook you up with a $50.00 credit toward any prototype service here at GPI. It may not seem like a lot but hey it's something (also a thank you for taking the time in watching both videos). Rate the video on youtube please and post a comment. If you are guessing on the 2 changes then please add me to your network on linkedin using this email. TimR@gpiprototype.com

Here is the Link. Please let me know what you think. (yeah I made that rhyme)

http://www.youtube.com/watch?v=88BPmL8cGAo

Thank you so much for participating, your feedback obviously was taken into effect, which is why I edited the video. I appreciate it very much!

Tim Ruffner
GPI Prototype - DMLS - Direct Metal Laser Sintering
[
gpiprototype.com]
Leave a comment here or on the blog and I will address them as I can. A lot of people wonder what the parts look like right out of the machine and if the steel is dense enough for finishing. We did our R&D and finished Steel and Cobalt Chrome parts. I just want to share the info with you! http://www.bit.ly/c5JRJI or visit http://directmetallasersintering.blogspot.com

Tim Ruffner
http://gpiprototype.com
DMLS - Direct Metal Laser Sintering
Tim (or anyone knowing): What kind of price range am I looking at to assemble a DMLS rig? I am leaning towards a Prusa rig to start but i am researching other add-man techniques along with costs and levels of effort to setup/operate/maintain.

The link provided showed a dollar amount of $650 which i am assuming was the cost to manufacture the one part and not the cost of the printing rig itself...hence my inquiry here...

Any rough price-range for the printer itself would be helpful...
Has anyone considered something similar to a laser printer? It's just a rotating prism and a laser that turns on and off. Line by line, it creates a two-dimensional image. Layer by layer, it could create a 3-dimensional object. Just a thought from a newbie, I don't really fully understand how direct metal laser sintering works.
VDX
Re: DMLS -Direct Metal Laser Sintering- Build Steel Parts for CHEAP
July 24, 2012 12:42PM
... this is used in some scanning optics for SLS-3D-printers - but most common there are two galvo scanners positioning the beam ...


Viktor
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