I think that using a roller to spread a layer of powder is probably the best way to do it. Here's an example: Might I also remind you of all the trouble NASA is having with vibrating powders.by Gene Hacker - Powder Printing and Selective Laser Sintering
Or instead of improving smoothness, print it as 2 interlocking pieces with a printed silicone gasket.by Gene Hacker - Let's design something! (I've got an idea ...)
Z-corp prints can be impregnated with resin and made very strong: IE strong enough for skateboardby Gene Hacker - Mechanics
You all may know that getting clean water is a big problem in many place around the world and that the ability of reprap to print water filters would be quite beneficial. So xerox recently came up for an interesting design of water filter that doesn't require micro-porous membranes, but instead relies on centrifugal forces to filter out particles. In other words it can probably be printed out bby Gene Hacker - Let's design something! (I've got an idea ...)
Here's the manual on how to use perfactory, it should clear things up a bit: It is interesting to note that a deck of playing cards is used to clean the build area after a build. It is also worth noting that perfctory is gravity fed and doesn't use pumps to get the photopolymer into the basin. Here's the technical details on the materials it uses: Apparently some builds have to have some soby Gene Hacker - General
FYI epson cartridges are made of polypropylene.by Gene Hacker - Powder Printing and Selective Laser Sintering
Fernando do any of those chemicals dissolve any sorts of plastics? Can they be dyed for color printing? BTW anyone know where to get some linear slide rails cheaply? I am having trouble finding some for my printer's new y axis.by Gene Hacker - Powder Printing and Selective Laser Sintering
Just found last year 3d printers: Apparently they were able to make a polar 3d printer that did metal extrusion. They also made a 3d printer that extruded molten sugar into cold water. From the looks of the flickr photo set, it looks like they even have a working reprap.by Gene Hacker - General
Check out these new 3d printers made mostly from laser cut parts built by Victoria university: Unfortunately, they don't seem to have much in the way of documentation...by Gene Hacker - General
Wait a minute, isn't laser toner something like graphite or carbon, and isn't carbon the stuff they use in resistors?by Gene Hacker - Plastic Extruder Working Group
I found this interesting(see 1171 C. Phoenix): The basic idea is to use paper tape and a fluidic computer to control hydraulic arms to machine UV curable plastic. A fluidic control system has several advantages over an electronic and mechanical control systems: fluidics don't have to be built terribly accurately, fluidics don't need to be made of several different types of materials, fluidicsby Gene Hacker - General
WOW! The print quality is amazing, probably as good as z-corp. I seem to have hit a hurdle on my epson though...by Gene Hacker - Powder Printing and Selective Laser Sintering
A cnc machine maker has an almost completely automated machine shop for makingcnc machines(see 728): As far as replicating a cutting bit why not use amorphous metal: I've heard it could be used to injection mold razor blades. The only reason why amorphous metal isn't used to make razor blades is that razor blades made from amorphous metal might "last too long."by Gene Hacker - General
To keep the mirrors in place why not add a hole in the ball joint so you can screw in some 8mm threaded rod to keep it in place?by Gene Hacker - Let's design something! (I've got an idea ...)
Epson color stylus 980, supposedly fast.by Gene Hacker - Powder Printing and Selective Laser Sintering
Also made boing boing, another top blog:by Gene Hacker - General
Hey Scorch could you give me some details as to how you modified your printer? I just got me a cheap epson I hope to convert to 3d.by Gene Hacker - Powder Printing and Selective Laser Sintering
Why use EDM when you can use the simpler electrochemical machining: But having a homemade ECM or EDM machine would really cool, EDM is accurate enough to make the molds for coins.by Gene Hacker - General
We could do those pieces, check out what the fab@home guys did:by Gene Hacker - General
You know, some of the early syringe extruder designs should be capable of dispensing solder paste and holding onto SMD components. If we could figure out how to make the SMD holding head rotate 90 degrees, store and align SMD components, and mill copper clad then PCB production could be fully automated.by Gene Hacker - Mechanics
Wow, lot of great progress here, looks like we might be able to play a game of chess with reprap after all. We might also keep in mind that the chess pieces need to be easy to manipulate too. We might start printing out chess sets as a way to show what reprap can do, chess sets can be quite elaborate if 3d printed: I also am beginning to see a need for having two plastic extruders, each capablby Gene Hacker - General
This is reprap so I'll recommend this (http://www.molecularassembler.com/KSRM.htm), it isn't a book, but it is just as interesting as one. This is also interesting too (http://www.islandone.org/MMSG/aasm/). Or instead of reading books why not put that spare thinking power to use and design parts for reprap?by Gene Hacker - General
Wonder what Speaking of chess partner, are reprap's dimensions big enough to fit in a chess set on its extrusion bed. Maybe we could have reprap print out it's own chess set, board , and piece manipulator. A chess match may be in order...by Gene Hacker - General
Absolutely. Albeit a fragile a fragile reprap, as fused powder tends to be quite fragile. But if you have the printer, you could keep making replacements until you have achieved 100% replication. Only thing you need to be worried about is parts melting, I don't know if the plastic it uses melts below the temperatures reprap operates at, but even then you could still churn out replacement parts.by Gene Hacker - General
I'm not talking about buying plastic bags, I'm talking about using the ones that litter the streets and fields. BTW, they are trying to ban plastic bags where I live because they supposedly clog up the storm drains.by Gene Hacker - General
Or you could just melt the ferrites.by Gene Hacker - General
Check out this instructable on how to mold with grocery bags: The author recommends using an oven to melt the bags rather than a flame, which produces potentially toxic by products. If we could make a plastic bag "harvester" and a plastic bag "digester" for reprap, we could reduce the cost of reprapped goods. However, parts produced through this method aren't exactly pretty.by Gene Hacker - General
I found two things funny about this: Z-corp uses food coloring and this quote "The Z Corporation adopts a printer-head made by HP and solely develops its own control card for controlling the quantity of deposited binders because the powder needs a large portion of binders in its composition." In other words, Z Corp doesn't make their own nozzles and probably uses nozzles from commercial printers.by Gene Hacker - Powder Printing and Selective Laser Sintering
Since the milling head is pretty much nixed, why not use electrochemical machining? Where you cover the work piece in salt water hook it up to a positive electrode and move a small metal syringe shooting salt water hooked up to the negative electrode where you want to machine the work piece. It might be possible to replace the syringe with pencil lead in aquarium tubing, for cheapness.by Gene Hacker - General
So reprap doesn't have a working mill head, guess I'll design an attachment for the extruder mount that allows reprap to 'assimilate' dremels.by Gene Hacker - General