This is reposted from one of our members, message me and I will help you get hooked up if you want to ride share. Also, is anybody interested in ride share from Balto? I live in Catonsville and am very convenient to the Beltway, bus lines and Marc train. I'm also driving a stationwagon down all 3 days. Reposted: How is everyone getting to this event? I was going to drive down but was alsoby BDolge - Baltimore/Wash. DC (and environs) RUG
The schedule for the Build-a-thon looks pretty solid now so here goes: Fri 23rd: 7-8 pm Volunteers meet and greet organizational gathering, perhaps some lite setup 8pm-? adjourn to nearby pub for socialization activities with liquid refreshments. Sat 24th 8-10 am Set up of facilities and RepRaps and more socialization activities with caffeine based liquid refreshments. 10by BDolge - Baltimore/Wash. DC (and environs) RUG
For what it's worth, folks who mill foam on a regular basis for casting use regular wood or wax milling bits in dremel type heads for their milling even though most have hot wire machines for manual use.by BDolge - Mechanics
Why bother with a barrel at all? Just build a toolhead with a soldering pencil tip and a device to feed solder wire in at the top of the hot zone. To use position the tip where you want to deposit solder, power up the tip, wait x time to heat up the tip and any wire/pad you're touching and then feed the wire. The solder liquefies and runs down the pencil tip until surface tension pulls it intoby BDolge - Plastic Extruder Working Group
I personally would not expect a "clean" break between Darwin and Mendal. Each "Mendal" component will have to be tested and troubleshot (troubleshooted?) and where will that happen but on existing Darwins? Some work on tool swapping has already been done as have steps on paste and metal extruders. A paste extruder allows not only support material, but also flexible (silicone rubber) and ceramiby BDolge - General
A patent covers a unique object or process. P&W can copy GE's turbine blade because turbine blades have been around forever and GE did not or could not patent the particular shape of this blade. If GE had patented a particular manufacturing method required to make that blade P&W would be out of luck until they developed their own version or licensed GE's. A design patent only applies iby BDolge - General
It's Official!! Zack "Hoken" Smith RepRap Guru, Fanboy and founder of the RepRap Research Foundation will be at HacDC, an open hacker space in North DC on January 24-25 for a RepRap Build-a-thon! The plan is to assemble an entire Darwin RepRap Acrylic kit over the course of a weekend in association with presentations on various topics of interest. This is a huge opportunity for the Baltimoreby BDolge - Baltimore/Wash. DC (and environs) RUG
As to the use of conductive epoxy, I believe that. firstly, its' resistance is too high for it to be practical for use on conductors more than a few inches long. One reference (which I can no longer locate)gave resistance values per meter in units I never really understood, but Copper was 17, Solder was 150 and silver bearing epoxy was 380. Conductive epoxy is also expensive, currently $1.70US/by BDolge - Controllers
Fab@home already has a thermoplastic extruder which uses hot glue as its material: If that (understandably) doesn't appeal the fab@ printhead carriage is relatively simple and modular and you should be able to hack a Bits from Bytes extruder on there with no problem (it's even acrylic, so everything matches). The problem you will face is that f@h uses a very simple stop/go print command with noby BDolge - Reprappers
Here is a link to a blog tracking their work: Interestingly they appear to be using a milled ABS surface made by reclaiming old printer casings. they also say they have greatly reduced warping by heating the base while printing. Has anybody else tried this?by BDolge - General
Here is a movie from the German hacker space Metalab showing one of our extruders at work on a regular three axis CNC machine, as well as some of thier results. I love the star shaped box!by BDolge - General
Always remember the Classic sign on the wall in every design shop: ----------------- 1. Fast 2. Cheap 3. Good Pick two. ----------------- For good you can read easy in this case.by BDolge - General
This is a very interesting technology/machine. For one thing the build precision is amazing in the photo gallery. The build precision seems to allow for 0.1 mm features which means that snap together and press together items are possible, making it easy to create hollow and larger than build area items. While the model to waste ratio is likely to be depressing, paper is almost infinitely recycby BDolge - General
I think Forrest has hit on the best approach. The first page of the "build your own" thread could be reduced to 2 buttons: (1) "I want to follow simple instructions to build a machine to print 3D objects with"- and (2) "I want to create a machine using reprap technology to suit my own situation or advance the reprap project". Choice (1) leads to a set of pages with directions for a less thanby BDolge - General
Pardon me , but my understanding is that the mechanicals of the Darwin are solid and available in a number of formats (bits and bytes sells kits and several description files are available for those who want to make various pieces by various methods). While the extruder is in heavy development, B & B sells parts kits and directions for making a standard mark 2 extruder are on this site. I kby BDolge - General
The next meeting is at my house on Saturday 10/25 from 1 til 5 pm. It is starting a little late for the convenience of Adam Hahn who has his Darwin extruding HDPE reliably in outlines but is having some software trouble with the infills. Hopefully somebody who is good with software (Mark?) can help him out. He says he will try to bring his machine with him so we can all have a look at a workingby BDolge - Baltimore/Wash. DC (and environs) RUG
The next Baltimore/Washington RepRap User Group meeting will start at 12 noon on Saturday, September 27th at my house (6 Wade Av Catonsville MD 21228 see previously posted directions). Hope to see lots of folks there after the summer hiatus.by BDolge - Baltimore/Wash. DC (and environs) RUG
If you are doing support material for an overhang in the Y direction (call it front to back) then your support must be dense in that direction, but it can be sparse in the X direction (left to right in this case) as dictated by the bridgeable length and the number of turns to be made. Thus a curved object would probably need to be dense in both dimensions, but a straight sided one could be relatby BDolge - Plastic Extruder Working Group
I fail to see the difference between "unique", "potentially unique" and "scarce". "Scarce" means rare or uncommon, "Unique" means one of a kind; therefor "unique" is the ultimate form of "scarce". To be "potentially unique" an item would have to be capable of having something added to or taken from it so that it would be unlike any other thing. Either the original item would be unique but it'by BDolge - General
The point of having an open database and showing searches is that duplicates become obvious (serial # xxx turns up in lots of places at once) so their value drops. This decreases the likelihood of casual copying (why decrease the value of what you just bought?) and decreases the incentive to mass copy for profit (each copy drives down the value and you become known as a purveyor of fakes). It isby BDolge - General
It depends what you mean by by "establish a brand". Yes it is hard to become the next Coke or GM. but Linux and Manolo Blahnik were both incredibly valuable brands in their limited fields before they became known to the general public. This is part of the "long tail" theory, that given a large enough (internet size) audience, a brand only needs to be valuable to a tiny segment (<1%)to providby BDolge - General
I think the real trick to this machine is going to be getting a consistent 25 micron layer of liquid across the build area. Surface tension/capillary action and viscosity are going to be relatively powerful at that scale and will tend to cause either dry areas (via non-wetting) or thick areas (via wetting meniscus). The "Vacuum Diffuser Module" is probably not easily replicable, but I wonder aby BDolge - General
I would be a little worried about wear on the tape, not only the usual physical wear and tear, but also I believe the process of reading a tape actually causes the tape to lose signal gain each time. As I recall the tape works by aligning lots of microscopic magnetic particles to create magnetic fields and the read head converts some of the magnetic energy into electrical energy, but the energyby BDolge - Mechanics
How about--- Reprap Enhanced Production by Repetitive Application of Plasticby BDolge - General
I vote for fused filament formation as a term of art for what we do and an abbreviation of 3F. We are after all fusing filaments to form things and while 3f generates lots of google hits they don't seem to be related to 3d printing on the first few pages. I have to say that I don't understand Adrians' resistance to acronyms, they are fairly inevitable and mostly harmless.by BDolge - General
Here is a related Slashdot article; Basically a US court has said that a digital wireframe is indeed the property of it's creator rather than of the creator of the original item. Good news for our side as they say, and it damages one possible method for "protecting" IP from scanning, which would be to assert that the copyright that applies to the plans etc. for an item extend to the item itselby BDolge - 3D Scanners, Book Scanners, and Optics
Here is a Slashdot article relating to a recent topic here abouts regarding IP issues re 3D printing/reproduction: Basically a US court has said that a 3D scan is legally equivalent to a photo, that is it is the property of the image creator, not the creator of the original. Good news fore our side.by BDolge - General
Here is a paper on fabbing zinc-air batteries from the folks who brought you fab@home:by BDolge - Let's design something! (I've got an idea ...)
Here's a link for the existing changer: I don't know if the STL files to produce it or the software to use it is available at sourceforge but you can have a look. This holder is only usable along one side, but a "carousel" or more likely a "ferris wheel" or endless belt of docks seems like the best solution for increasing capacity.by BDolge - Mechanics
Nichrome problems are predominantly: insulation failures leading to shorted out sections, expansion and contraction due to temp changes leading to flexing,strains and broken wires and it's just fiddly, springy and fragile to work withby BDolge - General