Lasers !?!
Posted by SebastienBailard
|
Lasers !?! December 08, 2010 03:01AM |
Tansen, (and other Labitat.dk folk)
Did you see the reprap-dev discussion about your work, and relevance of lasers?
http://reprap.org/pipermail/reprap-dev/2010-December/002038.html
Cheers,
-Sebastien, RepRap.org library gnome.
Remember, you're all RepRap developers (once you've joined the super-secret developer mailing list), and the wiki, RepRap.org, [reprap.org] is for everyone and everything!
Did you see the reprap-dev discussion about your work, and relevance of lasers?http://reprap.org/pipermail/reprap-dev/2010-December/002038.html
Cheers,
-Sebastien, RepRap.org library gnome.
Remember, you're all RepRap developers (once you've joined the super-secret developer mailing list), and the wiki, RepRap.org, [reprap.org] is for everyone and everything!
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Re: Lasers !?! December 08, 2010 09:09AM |
Hi
I think this quote is useful here "Its important to support all ways to belief"
Yes I have see the discussion, you can see the discussion so far below the dotted line;
Here's a few thoughts?
The route to dimensionally finished parts
An existing route to produce dimensionally finished parts is CNC combined with EDM ( electrical discharge machining) but these are high tool force processes so each different shaped article requires specialized attachment method by a highly skilled operator.
Electron beam melting printer and Focused Ion beam milling is a path to producing dimensionally finished parts.
Parts that have excellent metallurgy and surface finish, using low tool force processes.
SLS on the other hand produces near finished parts, so it is still needed to mill, grind and polish after printing, or severely limit the design to take this in to account.
The other problem is as Adrian Bowyer says " we will probably never be able to reprap a laser" so we have this cost factor; Nd Yag Q pulse lasers that are powerful enough to correct/ vaporize the metal errors are currently around 100,000 euro each.
Lower power lasers can sinter parts producing high porosity near finished parts ( ie not equivalent to milled / grinded metal parts).
Come on board and join any of the projects. Here Ebm , SLS has also a forum on reprap elsewhere.
kind regards
Rapatan
------------------------------------------------------------------------------------------------------------------------------------------------
Have you and the rest of the Labitat.dk reprap team experimented with
laser-sintering? It should be much easier to prototype.
Yes, but their goal of electron beam melting would be many times more useful if successful. Electron beam melting produces many times stronger parts than SLS and can be used in areas traditionally limited to milled and cast parts. There is a reason NASA is keen on this stuff
It's a lofty goal but I'd hate to distract the only team working on it with the arguably less useful goal of SLS.
Cheers,
Rob
On Thu, Dec 2, 2010 at 12:53 PM, Leo Dearden wrote:
Viktor, (or anyone?)
Do you have any information about (IR) absorption spectra for metals? I'm thinking specifically about laser soldering, but metal sintering is interesting too. Is there a good reason to choose 808nm vs 975nm for these purposes?
On 2 December 2010 11:48, Viktor Dirks wrote:
... powder-lasersintering is much simpler to realize than EBM - powders from plastic, ceramics and lignin (thermoplastic dust made from wood) or gold can be sintered with air, most metals reacts with oxygene, so need an inert atmosphere of nitrogen or argon.
Common fiber-coupled 9Watt-laserdiodes with 808 or 975nm wavelength can be bought for around 300 Euros from Lumics, i'm working with salvaged 5Watt-diodes with 975nm or 1Watt-diodes with 445nm, what's enough energy for engraving dark organic materials or melt many powder types ...
Viktor
Am 02.12.2010 11:43, schrieb Sebastien Bailard:
Tansen,
Regarding
[reprap.org]
Have you and the rest of the Labitat.dk reprap team experimented with
laser-sintering? It should be much easier to prototype.
Cheers,
-Sebastien
Viktor Dirks wrote:
... for ebm you need high vacuum, as te electrons can't pass any
atmosphere ...
Metal powder sintering can be achieved with a laser in inert gas much
easier, as you don't need a such rigid/stable sealed chamber needed for
vacuum.
I tried with 5Watt-diodes @975nm, whats melting all sort of absorbing
powders, even metals, but for on air oxidizing materials i'll need a
stream of Argon (pure Nitrogen is often enough too) on the melting spot
or better a chamber around flooded with Argon.
Much better sintering is with the 50Watts-fiberlaser @1070nm - i can
reduce the spotsize down to 5 microns for real superb accuracies, but
its melting mineralic and metallic powder even with 1 Watt energy at a
spot of 50 microns size ...
Viktor
I think this quote is useful here "Its important to support all ways to belief"
Yes I have see the discussion, you can see the discussion so far below the dotted line;
Here's a few thoughts?
The route to dimensionally finished parts
An existing route to produce dimensionally finished parts is CNC combined with EDM ( electrical discharge machining) but these are high tool force processes so each different shaped article requires specialized attachment method by a highly skilled operator.
Electron beam melting printer and Focused Ion beam milling is a path to producing dimensionally finished parts.
Parts that have excellent metallurgy and surface finish, using low tool force processes.
SLS on the other hand produces near finished parts, so it is still needed to mill, grind and polish after printing, or severely limit the design to take this in to account.
The other problem is as Adrian Bowyer says " we will probably never be able to reprap a laser" so we have this cost factor; Nd Yag Q pulse lasers that are powerful enough to correct/ vaporize the metal errors are currently around 100,000 euro each.
Lower power lasers can sinter parts producing high porosity near finished parts ( ie not equivalent to milled / grinded metal parts).
Come on board and join any of the projects. Here Ebm , SLS has also a forum on reprap elsewhere.
kind regards
Rapatan
------------------------------------------------------------------------------------------------------------------------------------------------
Have you and the rest of the Labitat.dk reprap team experimented with
laser-sintering? It should be much easier to prototype.
Yes, but their goal of electron beam melting would be many times more useful if successful. Electron beam melting produces many times stronger parts than SLS and can be used in areas traditionally limited to milled and cast parts. There is a reason NASA is keen on this stuff
It's a lofty goal but I'd hate to distract the only team working on it with the arguably less useful goal of SLS.
Cheers,
Rob
On Thu, Dec 2, 2010 at 12:53 PM, Leo Dearden wrote:
Viktor, (or anyone?)
Do you have any information about (IR) absorption spectra for metals? I'm thinking specifically about laser soldering, but metal sintering is interesting too. Is there a good reason to choose 808nm vs 975nm for these purposes?
On 2 December 2010 11:48, Viktor Dirks wrote:
... powder-lasersintering is much simpler to realize than EBM - powders from plastic, ceramics and lignin (thermoplastic dust made from wood) or gold can be sintered with air, most metals reacts with oxygene, so need an inert atmosphere of nitrogen or argon.
Common fiber-coupled 9Watt-laserdiodes with 808 or 975nm wavelength can be bought for around 300 Euros from Lumics, i'm working with salvaged 5Watt-diodes with 975nm or 1Watt-diodes with 445nm, what's enough energy for engraving dark organic materials or melt many powder types ...
Viktor
Am 02.12.2010 11:43, schrieb Sebastien Bailard:
Tansen,
Regarding
[reprap.org]
Have you and the rest of the Labitat.dk reprap team experimented with
laser-sintering? It should be much easier to prototype.
Cheers,
-Sebastien
Viktor Dirks wrote:
... for ebm you need high vacuum, as te electrons can't pass any
atmosphere ...
Metal powder sintering can be achieved with a laser in inert gas much
easier, as you don't need a such rigid/stable sealed chamber needed for
vacuum.
I tried with 5Watt-diodes @975nm, whats melting all sort of absorbing
powders, even metals, but for on air oxidizing materials i'll need a
stream of Argon (pure Nitrogen is often enough too) on the melting spot
or better a chamber around flooded with Argon.
Much better sintering is with the 50Watts-fiberlaser @1070nm - i can
reduce the spotsize down to 5 microns for real superb accuracies, but
its melting mineralic and metallic powder even with 1 Watt energy at a
spot of 50 microns size ...
Viktor
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