Looks like somebody wants to set up an X-prize for making a "RepRap Von Neumann":by Gene Hacker - General
The 2013 Solid Freeform Fabrication Symposium proceedings have been published, so we have details of how UTEP printed a motor. Apparently, they also have a nice method of embedding copper wires into prints by pressing heated copper wire into the print.by Gene Hacker - General
@MattMoses looks like it was presented at the 2013 Solid Freeform Fabrication Symposium as: "3D Printing of Electro Mechanical Systems" by Efrain Aguilera, Jorge Ramos, David Espalin, Elaine Maestas, Fernando Cedillos, Dan Muse, Eric MacDonald, and Ryan Wicker. Unfortunately, conference proceedings haven't been posted online yet. They will probably be posted here pretty soon. It also looks likby Gene Hacker - General
The details are scant, but it appears this electrical motor was printed by stopping the print mid-way to wrap wires and embedding magnets into the print. It should not be hard to replicate this with a reprap.by Gene Hacker - General
QuoteIs this because of metal porosity reducing the metal strength? Metal porosity decreases fatigue(degradation due to oscillating stress) life. Vehicles are generally designed to have a fatigue life of forever for liability issues. A car whose frame breaks randomly is probably not a very good car. EBM is done in an airless environment(one can't shoot electron beams in air!), but HIP'ing is stiby Gene Hacker - General
@garyhlucas, that sounds like Electron Beam Direct Manufacturing(EBDM), which is the LENS process's electron beam based counterpart.by Gene Hacker - General
QuoteDo you believe it will be possible to print the frame, engine, suspension or drivetrain of a car? If not today, then within a decade? What is the biggest difficulty with doing this in your opinion? You could print the frame today, but it would probably not be worth it. Electron Beam Melting(EBM) could be used to make parts of the frame out of titanium alloy possibly lighter than any other mby Gene Hacker - General
@johnrpm that's almost exactly the idea behind voxel printing. Though using electrical discharges for welding would certainly be novel.by Gene Hacker - Delta Machines
Printing stuff out of thin air is currently impossible, most current additive manufacturing processes do not directly transform air into workable parts. Now as far as electronic components go, resistors are trivial, the resistance of conductive ink is fairly high. The hard part is making something that isn't a resistor. Transistors have already been done. Only problem is that they are glaciallyby Gene Hacker - General
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 systemsby Gene Hacker - General
@ MattMoses seems like it shouldn't be too hard to make new relay contacts by printing a mold, which should last a lot longer than a single relay contact, for low melting point alloy and doing electroforming to make the contacts. Perhaps relay contacts can even be 'regenerated' by electroplating on to them. That's going to be quite a bit of contacts to replace though. Changing step rate is notby Gene Hacker - Developers
@VDX, that's similar to Voxeljet's continuous printing system. Although the printing happens in a 45 degree plane.by Gene Hacker - Developers
@MattMoses, I assume the sound card is failing due to the relays fatiguing? Perhaps we should use a solid state control system. In fact this early cnc machine happened to use a fair number of solid state magnetic amplifiers for it's control registers. This brings up another obscure data processing technology: magnetic logic. Magnetic logic is logic based around magnetic saturation of ferriteby Gene Hacker - Developers
@mung, I can't seem to get your distro to run. I try to login with the default password, but it keeps telling me it's incorrect. Also, what information do you want from the oscilloscope?by Gene Hacker - General
@nicholas.seward, you can certainly produce PZT via laser sintering. You can also produce other high-grade ceramics like superconductors(!) using laser sintering, though it looks like a fairly complicated process. As far as PZT goes it looks like there has been more success using PZT mixed with photopolymer slurry and a stereolithography type process.by Gene Hacker - Developers
Got a raspberry pi, a scope, and a stepper motor driver, so I'm willing to test when I have time. As far as the voltage issues go there's this:by Gene Hacker - General
Pretty much everything they said is doable, but I doubt it. Only thing that is suspicious is the price. Sure you can print a multicolor object at 25 micron, but it will cost you lots and you'd be better off aiming for the industrial market. I suspect they could do something like RichRap's experiments in color printing. They will probably have trouble sharply transitioning between colors. Thougby Gene Hacker - Developers
The only reason for using primitive technology like fluidics or relay computers is because they are easy to replicate. It'd be pretty hard to produce our own microchips without a "billion dollar fab." Sure a reprap constructed with relays/fluidics may be slow, it may be inefficient, but the point is it will replicate. One will still need a pretty advanced computer to generate the paper tape, buby Gene Hacker - Developers
@WillStevens depends on what you mean by complex circuits. Back when relay computers were common, UNIVAC built a simple completely fluidic computer called the FLODAC: dl.acm.org/ft_gateway.cfm?id=1464112&type=pdf NASA investigated making some fluidic stepper motors for actuating stuff inside the high radiation environment of a NERVA engine. It also has some nice info on designing fluidicby Gene Hacker - Developers
@WillStevens I'd try to stay away from printing the tape, storing a long length of rigid plastic tape is going to be difficult. It might be better just to use paper tape instead. If you are using relays that operate at ~1 Hz it might make more sense to move to fluidics which can operate at 10s of Hz easily. Fluidics are also a bit easier to print than relays as one doesn't require nails or coppeby Gene Hacker - Developers
Well if you want a steampunk stepper motor, I've designed a simple one based around a pneumatic wobble motor: It uses three inflatable silicone chambers to move a cycloidal ring gear around an inner rotor gear in the same way as the motor described here: It should have about 108 steps per revolution and about 0.9 Nm of torque. It is designed as a prototype, but if it was made bigger and withby Gene Hacker - Developers
This idea has been proposed many times before, but not necessarily using RepRaps, see NASA's Self-Replicating Lunar Factory summer study, James Dyson's self-replicating desert solar powerplant, and the Lackner-Wendt's auxons. More recently, Metzger et. al did propose a self-replicating ecology that incorporated 3d printer. That being said, no one's ever built one.... References:by Gene Hacker - General
I'm amazed at how functional printed harmonic drives can be, though I'm curious how long they will last. Any chance you could run one of these until failure, possibly with a mechanism to count rotations? Also what kind of torque can these things hold and how big are you thinking of making an arm? And if you're making a manipulator or walking robot, you really ought to see if you can't print a tby Gene Hacker - Let's design something! (I've got an idea ...)
There's no reason you can't use a paste extruder:by Gene Hacker - General
We probably could, the robots they made were printed with a FDM type printer, and they have the software they used to evolve robots available for download here: It shouldn't be too hard of a task to write these evolved robots into STL files using openscad and what not. Though if you are referring to evolving printers that's going to be a bit harder. At the very least we could do some evolutby Gene Hacker - Robots!
Why use fusion, when you can pave solar cells? There's quite a bit of interesting manufacturing processes you can do in ubitquitous high vacuum. You can even make structures from a concrete-like molten sulfur-regolith mixture using contour crafting:by Gene Hacker - General
Well, you can do electroless nickel plating, as is often done with stereolithography prints, then plate to that. Though electroless nickel is a really messy process involving chemical that aren't exactly environment or people friendly. Also, check out this really cool example of what you can do with electroless nickel and 3d printing:by Gene Hacker - General
While you may not be able to print strong materials, you can distribute material smarter. You can effectively make a "material stronger"(per unit weight). Using a process called topology optimization you can find the strongest, lightest way to distribute material in a part, you can often increase the specific strength of a part by about 1.5. Of course, this isn't the only thing you can do as Marby Gene Hacker - Let's design something! (I've got an idea ...)
I really don't like the term killer app, especially when we're talking about reprap. There's a little something called the "long tail phenomenon" that is quite relevant to us. I don't think customized insoles are reprap's killer app, as there customized insoles out there that are customized by baking them in a home oven then standing on them. A local camping goods store also has this hiking packby Gene Hacker - General
No, we need at least 60 watts of power(from one of the most efficient machines by far, probably more given that power input hasn't been measured) in order to run. At 60 watts(assuming no reprap host, best case estimates) I'm getting something like 3.3 hours of run time which is enough to make a solid plastic cube about 2 inches on the side. This probably isn't enough for some of the big parts onby Gene Hacker - General