Researchers at the University of Helsinki in Finland have succeeded in producing nano-sized metallic copper particles that melt at temps as low as 15-200C.by TheGuy - Controllers
Please re-read my sentence: "which can make its own parts"; every other adaptive aspect of reprap stems from that. First you complain that reprap projects are diverging, then you insist on evolution. Yes, we know all about Stratsys and patents, it's been mentioned. I notice you didn't comment on my last line either, I guess you were right in your first posting when you said "Call me a troll" thby TheGuy - General
It doesn't look like you're making suggestion for healthy and useful change, Reprapper. It looks like you are attempting to coerce others to follow your "lead" with vague threats of corporate take over and project failure. This is a healthy project with a dynamic community of committed volunteer workers. It has self-organized with a minimal guideline provided by Dr. Bowyer's steady hand and someby TheGuy - General
Hmmmm... wonder where my last comment went. Perhaps I was too abrasive and someone in authority erased it. I'll rephrase: I think "reprapper" is full of bologna. Reprap isn't failing at all, new technologies often take 20 years to reach fruition so reprap is far and beyond exceeding expectations. "Reprapper" should feel free to help develop the documentation and other problems sited. The amountby TheGuy - General
Let's see... Custom irrigation implements, abrasion resistant cultivation tools, assorted brackets. Also I'd like to print a julia fractal from the magnetic class of equations with a 4 head (or 4 material head) setup. Conductive, semi, insulator and paramagnetic (embed ed blend of manganese and cobalt particles) in a self-similar scale free arrangement. I suppose I could get by without the semicby TheGuy - General
There's a whole collection of posts about just such plastic and plastic bag re-use over in the thread "Reusing the plastic" here: I think those bags could be cut into strips and fed directly into the extruder with the right feeder mechanism.by TheGuy - General
Greg Egan has some good stuff. 2 other cool books are "The adolescence of P-1" and "Code of the lifemaker"by TheGuy - General
Here's another related article about "Solder made obsolete by growing copper pillars" which looks to play right into a lot of the electro-deposition stuff Adrian has been writing about too:by TheGuy - General
Some things to keep in mind: Conduction is largely a surface effect. Sure the bulk conducts, but electrons like to travel the most at the surface. Signal and power are 2 different things. Signal doesn't require the high conductivity you might want with power (to drive a motor for instance) eutectic metals are probably fine for sending signal maybe even up to driving an LED. Keeping power and siby TheGuy - General
It works! chemical engineers at Princeton have produced exactly the effect I was thinking of. 100 nanometer line widths! Check it out:by TheGuy - General
A simple laser cutter, the head of which could fit directly onto a reprap machine. Could be used as a polymer hardner too if it's hot enough to cut... Was gonna post this under machining, but no one seems to read that forum. Rock on reprap!by TheGuy - General
How about using a couple sets of small rollers to feed a plastic bag directly into the extruder head near the bottom of the drive screw? The last set of rollers could preheat the plastic film a bit. I understand that a strand is what is currently being fed into some extruders, a twisted plastic bag makes a pretty ok piece of rope. Would be heck-a neat to be able to recycle bags directly into partby TheGuy - General
Reprap has inspired a future-discussion scenario over at the Center for Responsible Nanotechnology. All 8 scenarios are worth reading but in Scenario #2: Positive Expectations, Reprap plays a central role. Rock on Reprap tribe!by TheGuy - General
Hi Fernando, how's the work o UV curing going? Oscillatory movement is an intentional part of electrospinning but I see no reason it would exist undamped in a controlled circumstance. The inertia of the filament is also a usable property although my thoughts on using the ES steering method with plasma spraying instead of electrospinning would leverage flow properties in the manner you suggest.by TheGuy - General
Spent my spare 3.5 minutes today tinkering with polymer mono filament and an electrostatic module. Easily got 7 inches of deflection from 7.5kvolts at 80hz. So the extruder head I envision could cover at least that much area with minimal expense. Picture 2 electrodes at right angles (or 3 at 120 degrees) connected to such an E-S source via some of those high voltage transistors. Or alternately, 2by TheGuy - General
Hey! What happened to my original post!? somebody chopped it out. I don't want to have to type that all in again! [ whoops! my bad, it got moved to page 1, sorry ] Glad everyone agrees that it is a sufficiently crazy idea. Those are usually the tastiest. I can't imagine someone mobilizing all the individual components to make the thing though. Would cost a pretty penny but work great. Interestinby TheGuy - General
Oh, I forgot to mention: this design would have almost no moving parts. I.E. no framework, no threaded rods, no end-stops or gauge wheels. Just those components that moved materials into the extruder head. Everything else would be achieved by magnetic or electrostatic steering.by TheGuy - General
Ok, this is far from simple or easy or cheap but it is definitely crackpot. I'm borrowing from 4 or 5 technologies for this idea. fluidization: plasma spraying: electrospinning: cathode-ray displays: So what you can do is, following one of several different paths to it, get your polymer into a liquid state as per the usual extrusion step but as it emerges from the nozzle you apply a powerfby TheGuy - General
You asked for crackpot.... It seems to me the limiting factor on an extruder nozzle is its dimensionality. The tip of an extruder has (fractally speaking) nearly a dimension of zero, a single point. So how about you stretch out the extruder, making it a line instead? A wide, thin nozzle like those used by cake decorators to make flower petals. That way you could lay down much more line at onceby TheGuy - General
Was gonna post a separate thread for this, but after searching the forums for ultrasonic and piezo motors/engines I found this line of thought which seemed more appropriate. Have any of you looked into ultrasonic or traveling-wave motors? They are used in cameras and such. They exist in both linear and stepper forms. More info here: The advantage here is very high degrees of precision in theby TheGuy - General
To whomever it concerns, the List of available files page ( ) has been corrupted by some bunghole advertiser. The link is fowled up with a cloud of links.by TheGuy - General
I live in southern Oregon, would love to communicate with any fellow raprappers in this part of the world.by TheGuy - Oregon, Klamath Falls RUG
Found an interesting article about some high level thinking on machine replication. The original article is from "IEEE Transactions on Robotics." but a synopsis can be found at Physics News: I especially like the point about simplicity being an integral part of efficient replication and that they had study a lot of the defining elements of replication. Reminds me of those fractals which draw enby TheGuy - General
Just did a quick Altavista search for peroxides and ultraviolet and immediately found far too many interesting links. I'm wandering in the back of my mind if anything like one of the metal oxides could be set up to contribute the necessary oxide under ultraviolet light? I'm not much of an organic chemist but something about that from my studies of catalysts is pinging my subconscious. Would be niby TheGuy - Polymer Working Group
Someone could mount a cheap digital camera and a laser right onto a reprap architecture and just use that to scan with. I bought a decent 640x480 pixel camera at Walmart for 16$US on sale. A simple line generating laser marker can be bought for about the same to give a bright illumination to just one set of points. The camera would need to be mounted at an offset angle to give actual elevation vaby TheGuy - General
Hi Fernando, thanks for the contribution to my idea. As far as the photoinitiators go, I'm guessing about the chemistry at this point in time, but both camphor and quinone are readily available materials so I'm keeping my eyes open for natural analogs while researching these synthetics. I think we can figure out something a lot cheaper than 16$ a gram. Thanks also for all the great links, I've beby TheGuy - Polymer Working Group
Well now, Adrian, you got to cut me some slack. When I searched for "UV curable" and etc. it didn't bring up that reference. How was I to know I should search for "dental fillings"? That camphoroquinone reference is righteous though. Now I can search out a cheap, less viscous form of acrylic resin and have a photoinitiator to tailor with, thanks! Maybe I can even use a polyester resin and get aby TheGuy - Polymer Working Group
I checked prices on UV curable resins and they run between about 25P/49 USD and 48P/95 USD per kilogram. Found those prices here: so there might be cheaper alternatives. From what I've read it seems all these UV curable are methacrylate based compounds which are usually quite a bit cheaper than the above prices.by TheGuy - Polymer Working Group
Re: Forrest, Please read thoroughly before commenting. As I said in my post: "a UV polymer could be extruded from a syringe with several of these LEDs positioned a couple millimeters above the layer being deposited. The polymer would remain liquid inside the opaque syringe but would harden once deposited." My idea was to use an extruder rather than a tank, as I said. Extrude the liquid monomerby TheGuy - Polymer Working Group