If you are curious about the technical details of designing and laying out gears and gear trains, you can download a complete, free, public domain copy of the 1922 edition of the American Machinist Gear Book from Google Books right now.
Two used units, anyway. You need to move quickly if you want the cheap one for $23.99:
Cracked casing. Has caused dog to grow third pair of legs. Still adorable. Good product.
Because after that one’s gone, the price jumps up to $2500:
Found this in some old abandoned village while on vacation. Older, Russian model (PU239)? Please inquire about shipping. Not responsible for damage due to radiation or explosions.
Or you could just visit the manufacturer’s website and buy it there.
And no, it’s not a joke, but you wouldn’t know it from reading the reviews on Amazon. The 168 reviews are, in fact, the best reason to check out the listing. Highlights include:
So glad I don’t have to buy this from Libyans in parking lots at the mall anymore.
I bought this to power a home-made submarine that I use to look for prehistoric-era life forms in land-locked lakes around my home town in Alaska. At first I wasn’t sure if this item would (or could) arrive via mail, but I was glad to see it showed up with no problems. Well, almost no problems.
Great Product, Poor Packaging
I purchased this product 4.47 Billion Years ago and when I opened it today, it was half empty.
I bought it for my cat
I bought this for my cat and put it with a flask containing poison, in a sealed box. Do you think he likes it ? I’ve not opened the box yet.
I like the looks of these custom BBQ appliances by Steve Stealey of BARRELSMOKERS.net.
The Solheim Rapid Prototyping lab at the University of Washington was in the news last March for developing a new 3D printing process that uses ceramic powder as an inexpensive alternative to the pricier substrates that are currently the de facto standard for powder-bed processes. Well they’ve done it again, this time with 20 micron glass powder, which is formed into an object by layerwise application of a liquid binder. When the part is complete, it can be sintered in a kiln to produce a continuous glass part. The official UW online press release includes a telling quote from lab co-director Mark Ganter: “It became clear that if we could get a material into powder form at about 20 microns we could print just about anything.”
Tetris tiles
Build an audio circuit prototyping board that will save you time and help you retain your sanity!
The idea of a hollow card or paper form buried in plain sand as a sacrificial mold for poured metal parts interested me. As the internet papercraft explosion has taught us, paper is really not a bad medium for 3D design, especially for the cost. Software like Pepakura will convert any 3D digital model into a papercraft one that can be printed out, cut out, folded up, and glued or taped together to make a reasonably accurate real-world replica of the original. What if, instead of using the paper as a positive representation, one were to use it simply as a negative space–a volume, supported by dry sand, that would survive just long enough to impart its form to molten metal poured inside?
As a first experiment, I designed a paper template for the pieces of a classic put-together puzzle often called “The Four Piece Pyramid.” The challenge is to use the four identical pieces to form a symmetrical three-sided pyramid. I chose this as form, first, because I think the puzzle is elegant; second, because all four pieces are identical so only one template design is required; and three, because the pieces are fairly simple, geometrically, and thus so are the templates.
