3D Metal Printer Projects?

I like the depositor/ powder level position and the main chamber. The collection and recycling system looks good too. Its a nice concept.

I have a couple of ideas/ suggestions though.

If you want to reduce vibration then why not just direct the laser with a mirror that is moved by steppers rather than move a whole slide. The maths will be more complex to direct it but it will be a lot faster and have very little vibration in comparison to moving the mass of a slide.

I would also suggest having the argon tank outside. That's a tiny tank to fit in there and they are very heavy being made of thick steel. Getting one of the even the small types in and out of a compartment could be a real pain and it would be easy to damage anything delicate by accidentally bumping it while maneuvering. Much simpler and safer to have a pipe coming out to an external tank.

---

Make your Mendel twice as accurate.
[www.thingiverse.com]

I think we've left the realm of the home user, entirely. Argon, lasers, ebeams...this stuff belongs in space. Can we simplify it? Save for the ignorant asphixiating (Argon) getting sick (chronic metal poisoning) being blinded (lasers) dying of cancer (metal powder particles) or acute sickness from vapors...I don't like it at all, sorry. I just can't see myself working it it.

I really like the ideas of induction melting vs. this. For the inert gas, nitrogen seems a better choice than argon for home use, and I think a vacuum makes sense but will be hard to implement. The added advantage of the vacuum is heat insulation though. Anyone have other ideas? At least with this method the main risks are slow vapor release and direct contact burns, I can see myself putting it in a garage, no question.

... you can add metal by galvanic processes - e.g. in a hypocritocal solvent, where the laser spot adds the energy/condition to start the chemical process of reducing metal ions to solid metal

---

Viktor
--------
Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]

VDX Wrote:
-------------------------------------------------------
> ... you can add metal by galvanic processes - e.g.
> in a hypocritocal solvent, where the laser spot
> adds the energy/condition to start the chemical
> process of reducing metal ions to solid metal

Okay, I see how it is. Especially for you, I designed the ambient Fresnel lens laser. IT columnates and focuses ambient light from your office into a small spot and liquifies everything on contact, generating plenty of gasses, lights, UV, and raw POWER.

Or would could just heat a filament of metal. Can't be that hard...erm, can it?

... it's a matter of needed and available energy (and wavelengths) ...

- for melting solid metal (wire/filament or the surface of a solid block) you'll need eenergies in the range of some ten Watts to Kilowatts in the IR range ...

- for melting metal powder some Watts to hundred Watts of IR are enough ...

- for starting chemical processes in an overcritical solvent you can get away with some Milliwatts of UV (e.g. a BluRay-diodelaser)

---

Viktor
--------
Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]

If you have a gas leak of either Argon or Nitrogen in an enclosed space and displace all the air you will suffocate. Anyone who does welding using any gas shielding should be well aware of this.

To be honest there are no truly safe ways to concentrate energy in to a small aria. An inexperienced user can hurt themselves severely with almost any power tool.

I can't see how you are really going to make any of these systems significantly simpler or safer. How will you print metal without metal dust or concentrating power or some other potential danger. You have to be aware and take the proper steps.

I don't think the average user is quite the target here yet anyway.

---

Make your Mendel twice as accurate.
[www.thingiverse.com]

... when handling with gases in an enclosed room you should have some precautions.

First/easiest is venting+exhausting, next step is an Oxygene-sensor, that triggers an alarm, when the concentration of O2 undergoes a level (we had 16 percents as trigger).

I was working for a company developing and building thermal conductivity sensors, that are precisse enough to measure concentrations of binary or trinary gas mixtures to some ppm's. And could be simply switched to 16 different combinations - e.g. Oxygene or Argon in Nitrogene

Have two of this sensors at home, one for measuring the Oxygene concentration in my basement, the other for testing weird ideas and firmware-optimizing.

But this type of sensors aren't cheap enough for us ... look for cheap singlechip Oxygene sensors instead ...

---

Viktor
--------
Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]

If we just look at how fast plastic printing has been developed over just a few years, we will see the same exponential rise with this technology. People just need to realize it means being able to manufacture Aerospace quality parts in their garages. The fact is, this is the bleeding edge.

To have a part in engineering this is an exciting priviledge! To think hardly anyone is working on what will be such a profound game changer. It has truly excited me!

There are many ways of simplifying this! That is just a rough sketch that I threw together with no thought of design. I simply put in the main parts with little thought to layout.

- Madkite, your two suggestions (external argon tank as well as mirrors and stepper motor) are wonderful ideas. They are just a few examples of how this can be improved.

Your point about using stepper motors is a crucial one. I have been wondering how to get high speed printing movement using a CNC. You can't... a CNC just won't cut it. The MECCO video below clearly uses mirrors, and that is just clever. We want an engraving action more that a CNC action.

Correct me if I am wrong, but a CNC is for cutting. For scanning large areas, we want mirrors. That, I am also assuming, means a smaller apparatus? Wonderful! What a great point.



With regard to simplifying the design... another example I can think of is having just one set of vent holes for the powder. (Don't know why I put three).

In the end I want something the size of a small fridge with I highly modular design so that individual parts are easy to remove and retrofit.

An important part of the design then is the frame because it holds everything together. We want a rack type setup where everything is held together by bolts and can be accessed easily.

- Simba, I have to politely disagree, but I respect your point of view. Simply because we are on the cutting edge does not mean that it's out of our reach. Just a few years ago any 3D printer belonged in space...

Also, most of the hazards mentioned are faced by anyone working with any metal (welders, sanders, laser CNCs). As for working with lasers, it goes without saying, wear the proper safety equipment. Besides the entire apparatus will be encased during operation anyway.

I personally love the DMLS process. However we have a pool of growing ideas...

- Madkites Hypersonic powder deposition
- Induction Melting
- Galvanic Process
- DMLS
- Metal Deposition

We need to do some tests on different powders to work out what wattage for given wavelength is required. It will be a function of particle size, speed of beam, wavelength etc...

Jethro.




.

Anyway whats wrong with space.

I always thought of mirrors more than moving axes. Mainly because all those silly military laser weapons had huge laser so you just directed the beam with mirrors. They never seemed to think that if it worked and was used lots the perfect armor would be just another mirror!

The mirror could be really light and tiny so only small, accurate and very fast steppers would be needed.

Gas tanks are a pain. I take everything over to my highly portable welder to weld as the tanks are so heavy to get out of the shed.

I will have to look up the galvanic process.

Now that something I would like to know. Where do you get the powders. I have some pure iron, aluminium and brass powder but I have not found anywhere to get anything else let alone aluminium alloys or plastics to try.

An DMLS machine could be modified or used as a base platform to do plastics too. So I think its really worth perusing.

---

Make your Mendel twice as accurate.
[www.thingiverse.com]

... the laser in your vid is a marking laser with most common a Q-switched NdYAG-laser, pumped by an arc-lamp or such. This devices are in price-ranges from 20k$ to some 100k$ ...

For scanning optics check the show-laser market - here you can get cheap chinese devices XY-scanning vector graphics with RGB diode lasers. Replace the lasers for more power and smaller scanning range, then you'll get a 'marking laser' for some hundred bucks

I have all the guts of an 25years old 3DSystem SLA-printer (electronics, optical head with XY-scanner, vat, Z-stage) in my 'scrapery' and will reactivate it by time.

With some luck I'll get a marking laser from 2001 similar to the one in the vid but with +100Watts of power, where the pumping lamp or driver is nonfunctional -- either I can fix the lamp, or I'll replace the NdYAG-laser (1064nm) with my 50Watts fiberlaser (1070nm) ... could be real fun

---

Viktor
--------
Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]

... for powders: - I've got some kilograms of different plastic powders and pigments for testing from a local company that makes granules for the injection-moulding industry ...
... lignin-dust from Tecnaro: [tecnaro.de]
... stone- and ceramic dust from a local company making gravestones
... some iron-alloy powder normally used for press-sintering from a scrap-yard
... carbonyl-iron microspheres with 1, 10 and 50 microns distribution from BASF -- factory was closed 1996, so not available anymore
... ceramic microspheres from Omegaminerals: [osthoffomegagroup.com]〈=1
... clay dust for cosmetic use from our local drugstore
... sand from the beach ...

---

Viktor
--------
Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]

Here is a source of cheap Titanium from china, the metal that interests me the most: TITANIUM

This is pure titanium 99.5 percent at $11-$14/Kg. The granule size is rated at 20-400 mesh, so I used this calculator to determine the granule size: MESH CALC

If I'm correct, the powder comes in size from 1.27mm to 0.063mm. Unfortunately much of the Titanium powder on the market is meant for Fireworks and so quality may not be high up on the concern list.

--

Viktor, that is just the information on lasers I was looking for! Where I can we find info on your build when you start it. I sounds like fun.

--

Just looking ahead quick, I have been thinking about warping due to contraction after cooling that Viktor pointed out. It looks like the EOS system runs hot... just look...



So it may be necessary to heat the powder bed until the entire part has been printed.

--

Uniformity of powder is one of the big challenges. I have been thinking about the best method for powder deposition. I like the idea of a wiper arm, with the powder in it, and tiny valves that open to let the powder fall through onto a curved sheet of metal that is being vibrated by an ultrasonic transducer so that each of the individual powder streams fan out evenly.

Perhaps a picture will explain better...





With this method, we want to avoid the below...



Jethro.

... for diodelaser I've collected some specs and infos here: [reprap.org]

My other lasers (50Watt-IR-fiberlaser, 40Watt CO2-laserengraver, TAE-N2-pulselaser with 337nm wavelength and 200ps-pulses @400kW) and the tools/applications with them are 'work in progress' ... mostly really slow paced, as I really don't have much free time at home

... but this could change soon

---

Viktor
--------
Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]

What is the galvanic process that's reducing ions to a solid?

Edited 1 time(s). Last edit at 03/21/2013 11:45AM by Simba.

... could be really different, depends on the salt/solution or chemistry or specific additives ... either heating the fluid in the spot near the surface, or add energy as UV-photons, so the equilibrium changes from a stable state to a chemical 'chain-reaction' ...

---

Viktor
--------
Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]

So I suppose this is what is needed... a DIY laser scanner. All that would be needed is to replace the low wattage laser with a high wattege one! Wonderful!

VDX Wrote:
-------------------------------------------------------
> ... could be really different, depends on the
> salt/solution or chemistry or specific additives
> ... either heating the fluid in the spot near the
> surface, or add energy as UV-photons, so the
> equilibrium changes from a stable state to a
> chemical 'chain-reaction' ...

You guys, this is an absolute win. There are so many challenges with heating and melting and lasers:
1. not mixing with existing reprap (DLP/FDM).
2. fumes
3. dangers of fire
4. warp
5. oxidation
6. redesign for each new kind of metal
7. powder inhalation
8. Most importantly, subliniear scaling of speed and energy requirements as the pars get bigger/faster, you need faster heating and cooling to get it working.

Doesnt a galvanic/ionic method solve all these??? how awesome if we could figure it out.

... you can find here some infos about laser scanning and the software for: [www.photonlexicon.com]

---

Viktor
--------
Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]

Simba, the Galvanic process definitely needs to be looked at. I for one do not understand it fully, but any process that makes things simpler, even a paradigm shift, is good. Simplicity, however, should not come at the price of quality.

Viktor, a whole forum just for laser scanners! Wow! Just what is needed... it is clear now, all of the professional DMLS systems use laser scanning.

The video below shows an arduino controlled laser scanner. I have a question though, what type of mirror can handle the high wattage we are planning to throw at it? I am guessing that you can't use a cheapo laser projector and just replace the laser pointer with a 100w fiber laser. How can we DIY this...



I have found this interesting presentation on Metal printing that outlines the different manufacturers. Presentation

In it, there was interesting information on the EOS system, and in particular the EOSint M 280, their flagship metal printer.

Some fun facts...

- Costs $680k per unit
- Has a build area of 9.85" X 9.85" X 12"
- Uses a 200w fiber laser (for an extra $50k you can have 400w)
- Printing TI64 with EOS costs $680/Kg
- Has an integrated nitrogen generator
- Can scan up to 7M/S (23FT/SEC)

$680 for 1 Kg worth of titanium printing is expensive.

At those prices, i'm curious. Why bother printing in metal if ceramics offer the same features (High compressible strength, high temp, long lasting, etc) only lacking in the key area that they are more brittle, and can't bend. For many applications this can be enough.

What do you think about ultra high temp Zirconia, and other furnace cements? I've wanted to 3d print them for a WHILE now. It would make stellar quality materials where feature sizes are 1mm or larger, you'd be hard pressed to break it due to dropping force even, and thats the cheap stuff, so how about high-end ceramics? They dry with water and can be baked in a standard toaster oven with ease

IT is $10/lb for zirconia adhesive. And you can't say many of these things for metals:

" Use temperatures up to 2400°C
High density
Low thermal conductivity (20% that of alumina)
Chemical inertness
Resistance to molten metals
Ionic electrical conduction
Wear resistance
High fracture toughness
High hardness"

applications:
" Precision ball valve balls and seats
High density ball and pebble mill grinding media
Rollers and guides for metal tube forming
Thread and wire guides
Hot metal extrusion dies
Deep well down-hole valves and seats
Powder compacting dies
Marine pump seals and shaft guides
Oxygen sensors
High temperature induction furnace susceptors
Fuel cell membranes
Electric furnace heaters over 2000°C in oxidizing atmospheres"
(Source : [accuratus.com])

About the conductivity, don't get to excited. I think about 600 C or so, zirconia vents off all its oxygen and becomes a pretty decent conductor. Not good for every day use !

Edited 2 time(s). Last edit at 03/21/2013 07:29PM by Simba.

The power a mirror could handle would surly be a simple matter of how much light it absorbs over reflecting. Absorbing too much would make it get hot and cause components to fail.

So it depends what kind of mirror it has and its properties to the wavelength used.

But also are factors of accuracy of the reflection and its movement. Which I'm guessing would come down to quality of manufacturing.

I have no idea if there are any data sheets on this otherwise someone could just get a cheep one and see if it gets too hot or blows up. Some simple fan cooling can sometime be all that's needed.

Its not something I have really looked in to but I'm guessing somebody here knows or has the bits and insane curious inclinatons required to try it out.

If you do have those inclinations just read about Isac Newton and Michal Faraday and you will feel much better and probably a lot less mental.

---

Make your Mendel twice as accurate.
[www.thingiverse.com]

... in the industry the 'time is money' approach is essential -- so they use high-speed, high-accuracy (and high-price) scanners and high power lasers, so the micro- to nanoseconds, the material is exposured to the laser are enough to melt it.

In the DIY-area time isn't so crucial, so a diodelaser with enough power to melt the dust in the spot, moved around with a XY-plotter can be enough.

For dark plastic powder (or solid) some hundred milliwatts are enough to evaporate or melt the material.

With IR-diodelasers with 5Watts and 9Watts of power I was able to melt (and evaporate) all sorts of dust from organic to ceramic or even metal, if it was black or absorbing enough of the energy.

This sort of high-power laserdiodes are in the range of 350 Euros per 10 Watts ... and I'm distributing salvaged diodelasers with attached fibers and 975nm wavelength for even cheaper (below 10€ per Watt), so would be a good basis for testing with 'space-technologies' in DIY

---

Viktor
--------
Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]

Nice one Viktor! What is the highest wattage laser that you can source? Perhaps a better question would be, what is the laser with the highest energy density, that you think will be affordable to hobbyists, that you can source?

The parts needed for a laser scanner are smaller and cheaper than those needed for a CNC.

So the motors we want to look at are called 'Galvos'. Galvo

In my experience, any website that sells a product without a price will be prohibitively expensive. So here is a hack job... Hackjob

For about $115 you can get the galvo motors and driver circuitry to make your own laser scanner.

Here is what you get...

1. two drivers ( X and Y)
2. two galvo engines ( X and Y )
3. two pcs spare mirror
4. two cables from the drivers to the galvo engines
5. two signal cables input
6. one galvo engines mount
7. one power supplier ( PSU )
8. one cable from the PSU to the drivers

Of course, the electronics used to drive 'show-lasers' at parties is not going to be perfectly suited to manufacturing a high tolerance part...

A major challenge, as Madkite has pointed out, will be the Math, the code to run these mirrors.

Further, what is Kpps? Thousand point per second?

As for better mirrors... here are some mirrors meant for C02 laser cutters. However, I am not sure if the mirrors are wavelength dependent. CO2 Mirror

The mirrors can be bought, for about $25, and come in the following forms...

K9 Glasses
Si
Mo
Cu

Which one will suite our purpose?

Best Regards,

Jethro

... I have some ten of the 5W and 9W diodelasers with attached 0.1mm fiber, that can be refocussed to a spot of 0.1mm without problems - see the regarding infos here (linked this previously too): [reprap.org]

The 5W diode needs max. 5Amps for full power, the 9W diode 9Amps ... but I'm driving them with below. 90% of this max-current, so they wont degrade when proper cooled.

The fibers are broken (the diodes are slavaged from burned fiberlasers), but can be precise 're-broke', so the end is clean and perpendicular for direct use without polishing. Will do polishing too sometimes, but have previously to collect the tools and bits for this ...

With this relative 'low' energies you can use any mirror that is metal coated on the top surface ... I'm sometimes using metal coated glass-mirrors from old copiers and laserprinters and cut them in short pieces.

But the most expensive part in a galvo-scanning head are the F-theta lenses, that focus the laser beam on a horizontal surface! - they have to be optimized for the specific wavelength and working distance ... so better start with the XY-plotter-setup ...

---

Viktor
--------
Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]

If super high speed is not your concern then why not make a mirror positioning system.

If you focus the laser with a fixed lens for a distance that is the distance of the mirror to the bed + the distance from the mirror to the lens then just have a flat mirror. Its not a huge machining feat to make up a gimbal type arrangement. Not for me anyway. Providing you design it with ease of machining in mind for the tools you have. You can print a fancy one after. Some small ball bearings and its nice and smooth and precise.

The positioning math is more complicated but not that bad. As long as a ratio to allow for smooth movement of a beam across a flat surface are allowed for the rest like start and finish angles are not all so complicated. That's just the math for right angle triangles. I did a beginners course in programming python and while programming is not really my thing its is easily capable of this. We must have some programmers here who this would be simple for. And if the angles of deflection are not too great then a smoothing ratio might not really be that important.

---

Make your Mendel twice as accurate.
[www.thingiverse.com]

Dear all,

I am seriously considering starting an open source project dealing with metal 3D Printers, so much so that I have a preliminary website up.

Those who are interested please PM me, I need suggestions, name for the project etc and I will provide more info...

To me it does not matter how long it takes to build up a community of interested people at it is a wonderful, long term project which I will work towards slowly.

If anyone has some experience with open source projects, I would be grateful for your input.

I just think that there is so much wonderful information in this thread, that I would like to compile it into a neat project.

Many thanks!

Jethro Hazelhurst.

My only concern is there are not really a lot of us.

Just look at this thread. I'm really enjoying it as there is literally nobody out there who its ever worth taking to about this kind of stuff. They just look at be blankly. Though I'm going down a little bit of an esoteric route I will admit.

But there its not even a handful or us.

And we are all trying different things. Which is fantastic as we may find what is practical and impractical or something new and maybe brilliant. But no teams of people anywhere in sight.

So, how much interest is there? Or is it that it all looks too scary to everybody so they don't say anything even though they think it is a good project for us to peruse?

Still a collection of information would be invaluably. Especially suppliers of unusual materials and specialist components. And all the knowledge and data to help others. Useful software too. And lessons from hard won experience.

---

Make your Mendel twice as accurate.
[www.thingiverse.com]

You guys (and/or gals), metal printer at home is a holy grail of 3dp. Let be honest, plastic parts can be fragile, light, and leave for want. Metal is far more attractive for many reasons, and let's not forget that is conducts heat and electricity well.

From what I've gathered there is enormous interest and people have not started the conversation because it seems so far out. But just look at shape ways and their big metal jewelry displays.

I suspect for everyone of us there are 100 others just watching, waiting. But please, try now to burn down my house or coal mine my canaries in the process.

Hey everyone, I haven't checked these forums in a long time, however if you look on the wiki you will find a lot of stuff on there about printing in metals and other full strength materials. I did almost all that library research.

You are talking about various methods of making stuff out of metal that may be pretty poor dimensional accuracy etc, but I was deliberately looking for approaches that could be used for full strength, full density, highly accurate (UT-5 or so), good surface finish parts (I forget how much), etc. production.

I won't talk much longer, cuz the stuff is there on the wiki for you to read, but there are a lot of free peer reviewed articles etc. For example, there are some on the method of making objects by firing particles at high speed at a substrate. I think they called it cold spray. It has some major downsides, though, in particular the malleability of the metal is all used up during the deposition process, so the result is a very poor quality, brittle part, prone to cracking. Also you cannot get full density with it, it is limited to a relatively poor density, and therefore strength.

The most promising approach I found was a hybrid approach called shape deposition modelling. They deposit a layer of metal, in this case stainless steel, and then machine it, then deposit another layer on top. The support material is copper because it can be easily etched away selectively from stainless steel with some nitric acid or something, I forget what exactly, but ss and copper is a common combo because of how readily the copper is removed while leaving the ss untouched.

The means to deposit the metal can vary, but I think simply dripping it on is probably a good approach. It is superior in many ways because the cost per kw is very low compared to a laser or any other heat source.

One of the main problems sdm had was the fact that the metal shrinks when it freezes. Mostly due to the phase transition, but some due to the temperature change too. This leaves residual stress in each layer. There are some docs that show in great detail the stress patterns produced during drop by drop addition of material. It is a large contractile force, which causes upwards curling. The object could be printed in such a manner that the curling is pre-compensated for by changing the shape being printed etc. or stress relief could be applied to each layer with shot peening or electropeening (a pulsed electromagnet that gives a kick like a single ball hitting the surface repeated at high frequency and scanned across the surface) or similar. One more approach would be to basically embed the object in ceramic as you go, and then heat the result while it is still embedded in ceramic so it cannot move, and hold it at high temp for a while to relieve all stress.

Some combo of these things might work... instead of ceramic, you might be able to use like a ton of copper I guess. I dunno. Also I wasn't able to find any ceramic materials that could be printed with. I have heard there are ceramics that are soluble in various solvents.

... I have to rearrange some other tasks to get more free time and buy all the parts for Argon shielding, but I'm definitely on laser-melting all sorts of materials including metals ... have powder, dust and microspheres from plastics (with pigments), lignin, glas, ceramics, metals and alloys.

Have different lasers too with wavelengths from UV to NIR and 10600nm (CO2) and sufficient powers to melt or evaporate the material.

But it seems to be only me (in Germany) working on this - have sold 6 IR-diodelasers in the last two years with powers of 5Watts and 9Watts, what's enough to melt powdered material ... but until now haven't get any feedback for this

---

Viktor
--------
Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]