I was trying to stay more or less "on topic" with both the fic and non, "on topic" being the topics of self replication, fabricators and their effects on society, societal change driven by technology, and tech books useful in a specific or general way for matter hackers. If we're gonna talk favorite sci-fi or general reading I have to warn you that every room in my house except the bathroom hby BDolge - General
Just to cause discussion..... Fiction- A is for Anything- Damon Knight >Post scarcity Dystopia at its finest Diamond Age- Stephenson >unavoidable Down and Out in the Magic Kingdom- Cory Doctorow >Post scarcity econ & soc 101 The Dispossed/The Lathe of Heaven- U K LeGuin >Post scarcity psyc 101 Schismatrix/Shaper/Mechanist cycle- Brucby BDolge - General
I like the signal vs power idea Guy. Here's an idea for a two mode conductor toolhead: Signal mode: The head positions itself over a connection point (component lead); the heating element moves down and across to engage the lead, after a moment for the lead to heat up a motor feeds a solder wire onto the heating element, after a few moments the land is filled and the head begins to travel alongby BDolge - General
Just a few semi-skeptical notes: First, here's a page about creating PCBs via copper plating: and here is the recipe for the plating solution, which is a fairly standard version: Now my reading suggests this is a not uncomplicated process involving conductive inks and large finicky designed tanks and that all the paths must be temporarily shorted together for plating to occur. More importantby BDolge - General
Being stranded in the good ole US of A I am having a hard time finding metric studding and was wondering if anyone knew of a close enough substitute for M5 threaded rod to use as an extruder drive screw? MSC and Grainger both let me down and local hardware is hopeless. I may have access to a lathe over the weekend so time is a factor. Thanks in advance! Brian Dby BDolge - Mechanics
So we're going to try for our next get together at noon Sat. the 9th. This should be a good chance to hang out with some cool tools as we're meeting at a home machine shop. Dave will send me directions so I can pass them along in case of direct contact. Hope to see folks there!by BDolge - Baltimore/Wash. DC (and environs) RUG
A quick note on the McWire version, At our recent RUG one member brought in his mostly complete McWire. He called it a good learning experience. His main complaint was that there was a lot of slop in the table movement, especially under load. While this probably not an issue for a small additive type machine, it will not scale well or support subtractive work. The model could probably be impby BDolge - Mechanics
My guess is that the clause is entirely non-transitive and intended to prevent people from "farming" the RRRF. By entirely non-transitive I mean that I take the phrase to mean that any item I buy from the RRRF is covered but any item I make with that item is not. Admittedly thermoplastic bought from RRRF is a gray area here. By "farming" I mean that due to the open source nature of the productby BDolge - General
Here's some info on a homeade injection molding device: The Gingery stuff is generally well written and based on experience, but can be a little hard to follow if you're not shop savvy. Interesting, but I don't see it as a RepRap component either.by BDolge - Plastic Extruder Working Group
Here is a link for a gadget sold for emptying out squeeze tube such as toothpaste and bathtub caulk come in: it's not too hard to imagine attaching a motor to this and using it to push goo out thru an orifice. Given the wide range of stuff (spackle, silcone rubber, glue, fast set epoxy, etc) that come packed in tubes this might be useful. Thoughts?by BDolge - Plastic Extruder Working Group
Given the responses I got I selected Saturday between noon and four PM as giving everybody plenty of travel time. The weekend of the 19th contains my wife's birthday, so I picked the 26th. Thus the first first meeting of the Baltimore-Washington RepRap Users Group (B-WRUG?) will be Saturday, January 26th between noon and four PM at 6 Wade Av. in Catonsville MD. Directions to 6 Wade Av: Takeby BDolge - Baltimore/Wash. DC (and environs) RUG
My guess (I'm not a polymer chemist but I play one on TV) is that the pooling shown won't have a big effect on the amount of pressure need to run the extruder. With vicous fluids resistance to flow is dependent on cross sectional size: small size = high resistance the relative size of the nozzle hole vs. the size of the pooled areas suggests that most of the resistance in the extruder is at theby BDolge - Reprappers
A couple comments.. A. One way to massively increase the number of materials that RepRap can work with (Which massively increases the number of things it can make) is to build in subtractive ability (milling, drilling, EDM, etc). The current frame probably won't support this due to lack of strength but any number of repStraps do and future models easily could. Subtractive work DOES require fby BDolge - Mechanics
I think it's time to break out the hardware and run some tests, but I don't have the time, so I'll shut up now.by BDolge - Plastic Extruder Working Group
This is not currently a homebrew process, but it is not hard to envision a set of machinery and procedures that would make it fairly straight forward. It is certainly no more dangerous than a lot of hobby pursuits. My point is that this is an area where the preliminary (Darwin level) work has not been done and that work will require people with particular skills if it is to go forward efficientlby BDolge - Polymer Working Group
Jay- Good idea with the pen, but remember that an exacto knife has to constantly change orientation so that the edge always faces the direction of travel. Which is probably not a bad idea for a toolhead but would require a constant flow of info from the cartesian system to the toolhead and the interpretation of that data, and is thus not an easy one. See you soon, Brian Dby BDolge - Mechanics
Wow- That last one is basically a software only solution. I mean yeah, you need a desk lamp, a checkerboard, 2 pencils and a ruler, but take a fiver to the dollar store and you're done. Limitations: one side rather than full 360, and probably not so good on dark colored objects but still...by BDolge - Plastic Extruder Working Group
followed by: The first gives the names of the best bacteria for lactic acid production and talks about how to keep them happy and provides some preliminary (but high tech and optional) steps for increasing the concentration of the lactic acid solution. The solution must then be concentrated to a useful extent (90+%) by distillation at 85C under a hard vacuum (1 mm). The second paper discussesby BDolge - Polymer Working Group
Just to avoid reinventing the anti-grav unit-- and obviously these are not integrated into the toolhead/table combo, but that is not a problem for me as I see the RepRap as part of a larger self reproducing workshop.by BDolge - Plastic Extruder Working Group
definitely on the laser cutter or perhaps its cheaper cousin the plasma torch. Both however should be dead simple once we have a router head as they are just 2.5-D heads, the main problem is finding a way to minimize the mass to be moved and protect the user from system failure. While we're at it how about a laser sintering head? Not for metal powder at first but for polyfoam or powdercoat materby BDolge - Mechanics
lost foam is lost waxes big and cheap cousin. Basically you create a version of whateveryouwant out of polyurethane (I think (I just know it as the pink stuff they sell in sheets down at the home store)) foam. You then add gates and sprues of the same foam and optionally coat the whole ting in plaster of some kind. Then you pack it in sand and pour in the very hot metal. Result: large noxiousby BDolge - Mechanics
some Other ideas: A dispenser for felt or other clothlike material A multi-part(5 or better) mixing syringe (with variable ratios) to allow the production of foamed materials or composites a syringe that can be refilled from a separate reservoir (small syringe gives excellent flow control but low capacity) a head for laying down solder traces for circuit boards and integrated electronics anby BDolge - Mechanics
I think the definition of what is a RepRap vs a RepStrap is going to be a fluid one for the next few years as the machines capabilities expand. The ultimate Reprap would be something you could turn loose on the planet's surface and watch as it made a working copy of itself out of dirt and air without any help. A Darwin machine can reproduce all of its' Darwin specific parts with the exception oby BDolge - General
Sebastien, I'm good, I just didn't want existing threads to jump about without notice. I like the new format, one suggestion; how about a forum for general or universal issues with printheads such as how to talk to the software and tool changer tech? Also are you planning to breakout the software and electronics forums? Thanks for all your work, Brian Dby BDolge - General
Hi Sebastian, If you move things significantly could you leave the old stuff (down to say the message list level) in place as hyperlinks to the new locations for a few weeks? Thanksby BDolge - General
I think this idea is fantastic!! It has always been my feeling that There were 3 big hurdles to be overcome before RepRap could really become self-reproducing. 1: strong rigid structural members - Replacements for the metal rods in Darwin- this is not a fundamental problem, either create a printer based on a sturdy plastic box (simple but uses lots of plastic) or find a way to use RepRaby BDolge - General
The candyfab project at is an offshoot of evil mad scientist labs and is doing good work and generating some activity in their forums. Also Make Magazines instructables feature has periodically had articles on CNC platforms (search under milling or robot) in fact one of these is the basis for the MacWire base as I recall. Also the good folks at CNCZone while devoted to subtractive tech have toby BDolge - General
Can we hierarchify (is that a word?) the forums? Thus: Level One Hardware, Software, General/Theoretical Level two under Hardware: printheads, movement stage, circuits and wiring, etc Level three under printheads: thermoplastic, syringe/pump/paste, subtractive/milling, sintering/fusing, etc and so on. The current divisions of People, electronics mechanics, and software are also valid.by BDolge - General
Can we hierarchify (is that a word?) the forums? Thus: Level One Hardware, Software, General/Theoretical Level two under Hardware: printheads, movement stage, circuits and wiring, etc Level three under printheads: thermoplastic, syringe/pump/paste, subtractive/milling, sintering/fusing, etc and so on. The current divisions of People, electronics mechanics, and software are also valid.by BDolge - General
By the seat of my pants I would say we are looking for a plastic that: melts between 120 and 200 degrees C does not manifest any undesirable fumes (or other bad behaviors) until 250 C low viscosity exhibits a volume change of <1% when cooling Is relatively chemically stable and insoluble is possessed of acceptable tensile strength and rigidity when solid is cheap is widely available To my knoby BDolge - Mechanics