3D model maker

Use the Mcor Technologies type of 3D paper printer to cut thin sheets of metal rather than paper. Each thin piece of solderable metal is coated with a thin film of solder top and bottom, or just top or bottom for the first and last metal sheet that is cut. The printer stacks the cut sheets together with a solder/heat compatible adhesive, or a metal adhesive if higher heat handling solder is not needed, to make a 3D metal object (5). If using solder, the object is "fired" in a 180 190 °C /360 - 370 °F common kitchen oven to melt the solder and bond the metal sheets together to create a 3D metal object. Expansion and contraction during heating and cooling would be calculated into the design for various metal types.

EDIT 2013-02-02 Additional ideas regarding combining sand casting or lost wax casting in order to economically produce products from iron or other more robust non-solderable metals (see links)

Edit 2013-01-27: I should add that this desktop printing concept is designed to be low enough in cost to place in home workshops or a small business with access to a common household oven or no oven at all if metal adhesive only is to be used rather than solder - when using aluminum or tin foil for example. This machine is designed to work only with relatively inexpensive solderable metals rather than materials like titanium or platinum. Existing 3D metal printers are larger and more expensive, and the 200 watt lasers needed for these machines are illegal for a commoner to own.

On another note: For kicks thin sheets of magnetic material could be cut to make a 3D object. The printer would not assemble the objects. A human or robot would assemble the pieces like a puzzle similar to (see link)

Edit 2013-8-17, 2014-10-02 Markus Kayser (1) has found a low cost way to use solar power to replace the laser in laser sintering 3-D metal printing. Kayser is currently 3-D printing glass, but metal, powdered or otherwise, can be melted via a Fresnel lens as well (2). A Fresnel lens is available on the cheap by removing the lens from old rear projection TVs found on Craigslist for free or a bit more. If the sun's beam can be focused to a finer degree with other types of sunlight focusing mechanisms, the detail of the finished product will increase. The solar 3-D printer could create a mold out of sand, then liquid metal could be poured in the mold. Microwaves will melt metal. No focused beams required as metal powder will attract and absorb the microwaves by unknown means; one could utilize microwave sintering for metal 3-D printing (4). See also "Directed Energy Weapons" (3) Then there is eddy current induction heating that melts metal. How tightly can the currents be controlled and directed in order to heat and melt each "stack" of metal particles. To hold layers together, maybe magnetism could hold ferrous metal particles together until the Curie Point was reached.

Edit 2013-08: Example of thin stacked metal sheets used commonly in production of electric motors -- in this case to reduce eddy currents (5)

Edit 2013-10-01: It just occurred to me that there is way to focus microwaves - the same way paint is focused - with a stencil. The Mcor Technologies 3-D paper printer, if converted to cut metal sheets in the same way it cuts paper sheets, could produce "negatives" that could be called Faraday stencils. The Faraday stencils would block microwave energy from going anywhere but to the "positive" portion cut out of the negative. The metal would only melt in the positive portion. No doubt that swapping out the negatives to create each new and different layer of a complex one off product would be too time consuming and process intense even for a robot, but would work OK on a product in which only two or three stencils were required, like a simple metal box or aluminum ribs for a constant chord airplane wing (6). However, if a single, infinitely formable, Faraday stencil could be created on the fly for each layer, perhaps Eureka would be apropos. Oh boy, now more to think about. Maybe a ferro fluid manipulated by magnets in the same way that magnets bend light in electronic televisions to form a multitude of quickly changing images. But, the heat of the microwave sintering process could create a "Curie Point" problem that would disable the magnets and consequently foul the the stencil images. Tallyho! on to thoughts of alternative methods.

Edit 2013-10-03: Instead of Curie Effect impacted magnetism, maybe varying frequency sounds could be used move the metal particles around, or to manipulate the shape of a Faraday stencil, with a controlled Chladni plate type of affair. Also, the Faraday stencil usefulness would be limited by the frequency of the microwaves. If the Faraday stencil had focusing holes to small, the microwaves could not get through to sinter the metal particles. Lasers will also lift and move objects (7), but the lasers required may be too powerful or expensive or illegal for home use. So many flies in the ointment there are, but so fun to think about.

Edit 2013-10-05: A 3D printer can use ceramic as a printing material (8); ceramic or other home 3D printable materials that could withstand the heat of melted metal (10) may be able to act as a mold for complex metal 3D objects like a sphere made of bent rods (9). If I recall correctly, some objects, due to their unusual shape can't be cast because a mold can't be made that will separate properly; in this case laser sintering would have to be used or less complex parts could be printed and assembled to create a complex design like a watch movement.

Edit 2013-11-09 OK, maybe electron beam melting [11] is the hot ticket for DIY 3-D metal printing. An illegal 200 watt laser is not required for EBM , but a "high" vacuum is. A 10^-4 meters of mercury vacuum is required for electron beam welding, which may require a multi-stage vacuum pump, which may not be doable on the cheap, but would be legal to own. A electron beam is also required; I am currently trying to determine if an electron beam generator, with the power required to melt metal, with "steering" controllable by a home PC, could be DIY produced at a low cost and with a small footprint.

Edit 2015-03-04 The Mcor paper 3D printer could create the model object that one would pour casting sand around. The metal poured in the casting sand would burn the paper out (though likely pollute the cast item it required critical strength) similar to lost wax casting. Just a thought.

Edit 2015-03-06 Paper mache printer. Make the printing material out of CHEAP ground up newspaper particles (shredded in an old blender) and glue resembling the consistency of the food paste used to make cookies and such on 3D printers for food, or the consistency of the hot plastic used on 3D plastic printing machines. Print out the object for final use or for a casting mold.

2016-02-28 Steel reinforced epoxy is not metal but it's start. This material has a tensile strength of 2424 PSI and will handle temperatures up to 300 degrees. The downside is the material takes six minutes to set and therefore take maybe six minute between layers. Maybe cyanoacrylate and other steel reinforced glues could be developed for specific applications. JB Weld has a long history of astounding metal repair accomplishments. [13]

2017-5-2 Use high heat JB Weld to bond the metal sheets together. Or use JB Weld high heat as an ink in a regular 3D printer. Search Google for "soldering sheetmetal" for more information on the original idea.