Machines like this have been laying kerbs for decades. They're under human operator control and extruding a single-layer course, but the extrusion mechanics are broadly similar.by murd - General
These machines are by definition "rapid prototyping", not "rapid production". In the days before rapid prototyping, skilled modelers built masters entirely by hand, tolerances dependent on the individuals' skill. A master rapid prototyped to .5mm tolerance establishes proportion and takes much less time and skill to improve that tolerance figure, consequently surface finish as well. Since propby murd - General
Government and materials suppliers publish hazard warnings. One dealing with ABS here: A good idea to follow the recommendations.by murd - General
Sebastion, I like the idea. A scheme is already in use by car manufacturers. Their parts systems use 9-digit numbers that designate model in the first three, grouping area in the second (engine, suspension, body etc), and part ID with the last three. It could be very applicable to reprap. If someone innovates something and proposes a designation, it could be listed easily and verified in a "pby murd - Administration, Announcements, Policy
There are a number of lower-priced commercial g-code-from-stl generators, Deskproto, STLwork and TurboCADCAM being three. TurboCADCAM can use other formats too. Each of them has graphic display modes that can show the complete file's toolpaths arrayed about the model. I'm not familiar with it, but it looks likely that the Linux EMC has a similar mode. BodgeIt, in the wider CNC world, a machiby murd - General
Stl isn't scaled, it carries either mm or inch units, absolute size. In amongst the documentation is the volume of Mendel printed parts, 1115cm³.by murd - General
I think it would be sensible to base the award at least in part on output from the machine rather than just the machines themselves. There was an old Philip K. Dick story called "The Zap Gun" that described an arms race in which successive generations of weapon from each protagonist were described as being more destructive, more able to be quickly used, more portable - except that none of them wby murd - Kartik M. Gada Humanitarian Innovation Prize
Interesting to see your workflow, Viktor. For mine, I use TurboCADCAM for design and UltimateUnwrap3D for layout, and work with styrene sheet. I think we're doppelgangers. Murrayby murd - Casting and Moldmaking Working Group
Ed explained that he'd designed Mendel to steer away from trapped nuts in the release video. I'm building molds for the pieces but I'm using styrene sheet flat pieces that just plug into a base for the mold. The molding and mold faces come away together once the compound has polymerised, and the flat sides split away from the molding. There are rods pushed through the cavity that slide out leaby murd - Casting and Moldmaking Working Group
You're right about the steppers. The vrml file has them. I used Alibre to produce a 3D pdf from the STEP. My version of Alibre doesn't differentiate colours for the pdf assembly, but it's quite lucid even without, and swinging the pdf model is a lot more responsive than the vrml is in Cortona.by murd - General
Thanks, roj! Didn't realise that was there, whatever search terms I tried weren't the right ones.by murd - General
Apart from Ed's Solid Edge original, the other GA that's available is a vrml that's drifting about on the wiki somewhere. It gives a clear idea of the parts, but so do the pictures and instructions with the assembly guides. If you want to modify the parts to suit your own purposes, I'm confident that SolidWorks will import .stl, and those individual part files are clearer to work with individuaby murd - General
Pipe differs from tubing because it's categorised by nominal internal bore, accounting for flow capacity. Most countries that have used imperial measurements have had an equivalent of 3/4" nominal bore. 22mm outer diameter is 7/8", which is the usual outer diameter of 3/4" n.b., or 19mm, pipe.by murd - General
Chill, Dman. I've worked with a loose affiliation of retired engineers and technicians from a spectrum of disciplines who innovate and contribute their skills to create devices to help people with medical or physical disabilities or problems. They're often able to come up with something that medical engineers haven't considered because they're too focussed. Cross-fertilisation of ideas bringsby murd - Powder Printing and Selective Laser Sintering
Dman Wrote: ------------------------------------------------------- > Ideas are good....ripping off ideas is bad. End > to that non-sense. > Have you seen something that isn't built on prior art? Patents give commercial protection for 20 years, they aren't thought blockers. Your sentence skates close to plagiarising Orwell, BTW.by murd - Powder Printing and Selective Laser Sintering
There's a liquid acrylic copolymer product called Forton VF-812 that improves the strength of plaster mouldings and waterproofs them. The plaster mix is gypsum, melamine and ammonium chloride. The acrylic can be diluted with water, and the setting can be accelerated with aluminium sulphate. If it can be diluted to a suitable viscosity for an ink cartridge, it might be a good candidate for a biby murd - Powder Printing and Selective Laser Sintering
Lasers vaporise the material in the beam, I don't understand how this displaces it. Is it sheared out, does it punch through like a projectile, or is it vaporised or decimated? It sounds like it goes through like an armour piercing shell or similar, but even those cause local deformation. Is it noisy? Surely something that can deliver that sort of concussive force should be?by murd - General
Ditto that! Am partway through, enjoyable education is a wondrous thing, thanks to Prof. Slocum for his altruism, too.by murd - General
The interactive page that Splinescan used to have was interesting. It had a script that displayed one picture of 1000-and-some, dependent on where the cursor was on the page. I think that the cursor position referenced camera position for each shot. I was interested enough to save the source code, got it on a drive somewhere.by murd - 3D Scanners, Book Scanners, and Optics
I was a builder long ago. When we were pouring concrete floor slabs, we would have level edges on the side formwork and we'd pull a vibrating screed that spanned the edges along the slab as the concrete was poured to level it and give a preliminary finish. I wonder if a vibrating wiper would help consolidate the powder bed surface as the build progressed. It might reduce binder bleed through tby murd - Powder Printing and Selective Laser Sintering
The european electronics magazine Elektor did a collaborative deal a couple of years ago, running a series of articles with a kit available for a cnc pcb drill. The thing that was unusual about it was that it was a polar coordinate machine rather than cartesian coordinate. That might be a good scheme for a powder printer, with a continuously rotating climbing build rather than discrete layers.by murd - Powder Printing and Selective Laser Sintering
It makes it easier to join meshes in meshlab if you scan a reference object along with the prime object. If a cube is attached to the prime object while scanning, above it like the star on a Christmas tree for example, and fixed in the same relationship to the prime target for the two or three scans that you're positioning, there are at least three explicit vertices on the cube in each scan to uby murd - 3D Scanners, Book Scanners, and Optics
Sebastion, David has a feature called mesh2flash, which embeds an .obj, with or without texture, into a page as an interactive flash object. Can be done in any page, provided admin enables it. It's a free part of David, and can do any .obj, it doesn't have to be the result of a scan. You can have a look at what's possible here: Whaddya think?by murd - 3D Scanners, Book Scanners, and Optics
The XY bed of my repstrap is a decommissioned pick'n'place machine, about 220 x 180 mm travel, that I glommed off ebay. Solidly and professionally built from 6mm aluminium sheet (anodised blue, pretty!), acme 1/10" pitch leadscrews with bronze nuts, ball gibs and NEMA 23s (pretty old, but with shaft encoders) provided, cost me about USD100 landed in Australia. Considering the weight of the thiby murd - Pick-and-Place Electronic Assembly (and robots!)
I've been using CAD to earn a living for 20 years and each time I've tried Blender it's felt like I've fallen through the looking-glass. Its powerful, but it's so arcane and counterintuitive if, like me, you've been born and bred on trad CAD. Increasing age brings a reluctance to expend whatever time's left on a learning curve that steep. Looking at the modeling tutorial, even printing a pageby murd - 3D Design tools
I have a David setup, and it's remarkably good out of the box even with a hardware store line and a common-or-garden CCD camera. There's a free version and a "pay-for", I chose the pay-for because it has an integrated software component and assembly UI to orient and conjoin point clouds and surfaces from opposite faces of objects, which works very well with a reasonably fast PC. I like David beby murd - 3D Scanners, Book Scanners, and Optics
In Australia? Metric, theoretically since the mid '70s, in practise imperial's been a hard habit to break for hardware stores. Both are almost universally available.by murd - General
This picture is the geometry laid out against the part. The part should be mirrored about a 30° line, which is how the red lines have been generated. Within the green ellipse, you'll see that the edge of the part isn't parallel to it's complementary red line. Don't know nuthin' 'bout no Blender.by murd - General
There's another OpenCascade-based CAD application under open source development on SourceForge now. From the blog posts about it, it's developing very quickly and the developers have big plans. I've just started working through the tutorials and checking it out, but it looks good. Has a couple of things that the other OCC projects haven't arrived at yet, like splines and spins/lathes. NaroCADby murd - RepRap Host
Who did the original? It's got a Danny Kaye or Victor Borge feel about it.by murd - General