Colin: You are correct about current consumption patterns, but these are distorted by the simple fact that eventually it becomes difficult to find things (short of potlatch) to spend a significant fraction of ones income on. Thus any car is a large part of my income, but no car is a significant part of Warren Buffets income. Aside from deliberate ostentation there is a limit to how many materiby BDolge - General
Odd and Random thoughts: Given the current highly subsidized energy regime and the global wage disparity it is often cheaper to buy completed goods (tee shirts, tube socks) than to buy the materials ( cloth and yarn) if one is buying commodity clothes at a big box store. This is the big reason that sewing is in decline as a household skill, it is simply no longer worth your time to do it if youby BDolge - General
Brenden: You seem to be conflating two distinct things: 1. There are some people who are not motivated enough by social rewards to work after their survival needs have been met. and 2. There are some nasty jobs that are done by people who have little in the way of skills or talents to offer. The first problem is true, and is true, as you point out, in a money/scarcity economy as as well as aby BDolge - General
Brenden: For "elevate" substitute "pay" and your problem is solved. Money is just a way for people to easily negotiate for what they want. If you call it wuffie or prestige or semolians doesn't matter as long as everyone agrees to trust it as having consistent value. Even in Europe where basic sustenance is treated as a right some people are still garbage collectors and sewer muckers. Peopby BDolge - General
Always with the slaves! Why is it that people, when trying to imagine a world outside of the known always fall back on emphasizing the worst of human nature when the best, or at least the better, is what normally prevails? (By the way, there are good reasons why altruism and cooperation prevail; call it system dynamics, game theory, coevolution, sociobiology or the golden rule, in social situatby BDolge - General
I just want to say that Jay acquitted himself very well in what was a self described "very tough room". Also just a few days before Jay ran a RepRap table at Robofest which you can figure out what went on there for yourself. Jay has become our lead RepRap evangalist in the Baltimore/Washington area. Thanks and Congratulations Jay!!by BDolge - Reprappers
So first, a pound of caviar is never likely to have the same VALUE as a pound of poo, unless you REALLY need fertilizer. They might have the same cost of production, but value is a judgement. I value many of my books more than my TV but the TV costs more. Similarly with my children vs. my house. Assuming technology makes the production costs of all objects uniform people will simply find valby BDolge - General
Perhaps I am confused, is PCL the same as "Friendly plastic" or CAPA? This was the original plastic tested on the extruder. It becomes very soft in hot but not boiling water. If that is not feasible has any thought been given to something like play dough or some sort of water soluble material?by BDolge - Plastic Extruder Working Group
Has anyone tried bonding other plastics to PCL? My thinking being that it's melting point is so low that it could be washed out of the finished object with hot running water, caught in an ice bath and recycled. If it was necessary to raise the thermal mass of the PCL it could be mixed with clay slip. This would make it melt more slowly but at the same temperature and possibly increase "grippynby BDolge - Plastic Extruder Working Group
They are called Hemostats, also Roach Clips, but that's just what I've heard.by BDolge - Reprappers
This months Baltimore/Washington area RepRap Users Group meeting will be Tuesday, April 29, 2008 from 7 PM - 9 PM. We will gather in Room 114, Smith Hall of Art, George Washington University 801 22nd St NW, Washington, DC 20037. For those of you who missed our last meeting, the reason for the change of venue is that this is the time and place for the monthly meeting of Dorkbot DC a group devoteby BDolge - Baltimore/Wash. DC (and environs) RUG
Why not simpley build a freestanding box just big enough for your Darwin to fit in snugly? If your goal is an enclosure for industrial design, safety and temp control I see no reason to attach the box to the machine. Just a thought.by BDolge - Mechanics
If you were to deposit layers of solved ABS and purposefully heat them above 50C you could create an interesting material; light, rigid, thermal and sound insulating and possibly useful as a sacrificial shock absorbing liner. Just a random thought.by BDolge - Polymer Working Group
This is already being done in a way:by BDolge - Let's design something! (I've got an idea ...)
By request this months meeting will be Saturday the 22nd starting at noon ending no later than 4pm, at my house in Baltimore at 6 Wade Av. directions follow: Take your best route to the 95/695 junction, head west toward Towson. Take the Fredrick Rd (Rt 144) exit (exit 13). Head South back over the bridge, immediately after the bridge and opposite exit ramp is a small brick building, turn leftby BDolge - Baltimore/Wash. DC (and environs) RUG
Welcome home Shaun! If you check at the bottom of the forums page there is a section for RepRap Users Groups, if you find one in your area it will be your best resource, if you don't find one, start one, it will become your best resource. Parts: The RepRap parts lister: can get you started, most of the stuff comes from McMaster Carr and Mouser but you can get it from Radio Shack and your locaby BDolge - General
Heres an alternative: If you do a google search on "inkjet printed polymer integrated circuit"you'll see lots of folks doing very similar work with a modified inkjet printer. This looks like it could be a game changing technology if it comes down to a tabletop level. Brian Dby BDolge - General
Burning out is the technical term for melting the wax as you discuss. The term covers the fact that sometimes wax pools in undercuts of the mold, as well as the fact that other things, like sticks or bugs can be invested and thus cast "from life". For that matter foam can be invested and burned out. As I said I want to try CAPA (low temp thermoplastic) in both an invest and melt out and a pourby BDolge - General
Andy- Are those wax mixes you're referring to extrudable? As in capable of being forced thru a .5mm hole and then retaining the resulting thread-like shape? Most waxes have a fairly abrupt phase change from solid to liquid, rather more like ice to water than like say silly putty which just slowly gets softer the warmer you get it. Those look like good carving waxes which tend to be hard withby BDolge - General
Re casting: a lot of people have furnaces for melting metal that are made inside 5 gallon drums, I knew a fellow who had a collapsible furnace that folded flat. Sand takes up more space but if you're willing to kneel on the ground to fill your flasks the whole thing will store on the floor of a closet. Melting and pouring need more space and outdoors but can be easily done in a pair of parkingby BDolge - General
A lot of good stuff here. I agree with DG that the workshop is an idea with a shelf life, but I want to focus on what can be done in the next few years by ordinary people to make their lives better. FDM is a great technology and definitely the heart ands soul (or bread and butter) of the workshop. And for a lot of people it will make way more sense to buy mass produced rods and bearings and wby BDolge - General
Well I happen to think that bronze is still prettier than iron and jewelry sales say most people agree with me. Iron tools probably won out because they were more durable than bronze, not cheaper. Iron shows up in the archaeological record in the same way you would expect any expensive item to, first in jewelry and decoration then in weapons, then in tools and everyday items. Iron was initialby BDolge - General
Forrest- I like the FDM ceramics, do you know where I can get some more in depth info? Still a ceramic hammer is lighter than a metal one (thus less efficient ) and prone to shatter rather than bend. Every material has it's best uses and there is no single way or substance that will replace everything else, especially when you start paying attention to people's aesthetic wants as well as theirby BDolge - General
Forrest, Yes, the Gingery lathe is a lot of work, that's why we want to automate the process ;-). Yes foundry work can be dangerous, so can traveling at 80 miles per hour. We have safeguards and procedures that protect us. I've done castings with bronze, zinc, aluminum, and iron. The basic rule is stay out of the way of the hot stuff. That and be able to put out any fire you start pretty mucby BDolge - General
I'm not trained in these sorts of things, but if I recall moore's law applies to available computing power rather than cpu speed per say, so multicore machines are fair continuations of the trend, as is the fact that tons of graphic computations that are now offloaded to graphics cards. As I understand it the reason CPU performance has stagnated on the desktop is because demand is saturated. Thby BDolge - General
Sean- I agree that most folks don't have alot of room these days, but an HDPP hammer isn't good for much but threatening your siblings. Materials matter. A machine that can make a copy of itself is only a curiosity unless it can make other things people want. Look around you and I would bet you find very little in the way of STRUCTURAL (as opposed to cosmetic) thermoplastic. The last thermopby BDolge - General
In order to agree with Sebastian I should probably state my heresy at the outset. I don't expect to see a self reproducing machine in the next 20 years, even allowing people to do the assembly. I DO think we can achieve a self reproducing WORKSHOP in 5-10 years given a few bright but not technically skilled folks to do assembly. By workshop I mean a suite of machines, most of which are faberby BDolge - General
A wise old hippy once told me that "you can accomplish anything if you don't care who gets the credit."by BDolge - General
The Talk (from a slashdot link): My thoughts: NG seems to believe that fabrication is just a way station to a world of "smart matter" in which our surroundings would be composed of materials combining embedded computational ability with self manipulable structures; imagine a carpet that senses the number of people in the room and grows sufficient chairs, with placement based on time of day andby BDolge - General
Since a core goal of the project is to make a machine that can reproduce its' own parts it should theoretically be simple to make a new printer for each printhead that is desired. In practice however there are at least 2 problems. First and fundamentally some heads such as thermoplastic and support material have to work together; even if alignment and other logistical challenges could be overcomby BDolge - Plastic Extruder Working Group