Last chance to enter The Hackaday Prize.

And So Castings Made of (Kinetic) Sand . . . Turn Out Pretty Well, Actually

sand castingThat kinetic sand stuff is pretty cool. It’s soft, it builds motor skills, and outside of sprinkling it on carpet, it’s not messy. If you don’t know, it’s 98% sand and 2% polydimethylsiloxane, which is a major component of Silly Putty, and according to a certain yellow and red clown, it’s safe enough to put in chicken nuggets. [Chris]‘s wife bought him some, probably because she wanted to see him play around with something that isn’t potentially deadly for a change. In the course of researching its magical properties, he found out that it doesn’t really have a thermal breakdown point, per se. At high enough temperatures, It vitrifies like a sand castle in a mushroom cloud. Between this property and its malleability, [Chris] thought he’d have a reasonable substitute for founding sand. As you can see in his latest experiment, he was right. As a bonus, he managed to turn the benign into the dangerous.

[Chris] had never cast aluminium before, so he decided to start small by making an offset cam for a rotary broach. He packed some magic sand in a wax paper cup and shoved the cam in to make the negative. Then he cut down some aluminium rod and put it in a graphite crucible. He stuck his DC arc welder’s electrode down into the crucible and cranked it up to 50A. That wasn’t enough, so he went to 110. The crucible was soon glowing orange. He carefully poured the molten aluminium into the mold. Make the jump to see how it panned out.

Spoiler alert: there’s no cussin’ this time!

[Read more...]

Pimp My Cutting Fluid Pot

oil pot

Think about the simple tools you use every day. From writing implements to wire spoolers, there is arguably nothing that deserves to be hot rodded more than the things you depend on and might even take for granted.

For mad machinist [Chris], one of those everyday tools is his cutting fluid pot. Of course he already had one. A heavy one. A manly one. But it wasn’t completely ideal, and it wasn’t plated with gold that he prospected, refined, and processed himself. More on that in a minute.

[Chris] had obtained some neodymium ring magnets a while back. He was playing around with them in his shop when he noticed that his cutting fluid applicator brush fit nicely through the center and, being metal, was contained nicely through the wonders of magnetism. It was then that he decided to build a cutting fluid pot that would keep his brush in place and remain upright. Better living through magnetism.

He drilled and chamfered the brush hole out of a #20 JIC hydraulic cap and used the matching plug for the base. In case your catalog is out of reach, those are a 1¼” pair. [Chris] bored tiny pockets in the base for tiny magnets. After bathing both parts in delicious brake cleaner, he adhered all the magnets with LOCTITE®.

Okay, so, he’s done, right? No. Of course not. It did not surprise us to learn that [Chris] is also a miner, and not the 8-bit kind that hates creepers. Over the last two years, he prospected, refined, and other gold-related verbs using equipment he made himself. Just make the jump and watch the video before we give it all away. You’ll laugh, you’ll cry, you’ll be compelled to watch his other videos.

[Read more...]

Achievement Unlocked: Drill a Square Hole With a Rotary Broach

square hole rotary broachThere are times in a man’s life when he needs to drill a square hole through an 8mm thick piece of steel. If that man doesn’t have one or two thousand dollars to spend on commercial tooling to do this, he might just shrug his shoulders and make do with round holes. But if that man is [Chris], he rolls up his sleeves and makes his own tool to drill square holes with a rotary broach.

This tool that [Chris] has named the Wobble Drive drills a square hole by applying force to each of the corners of a square bit one a time. How, you might ask, did he achieve this? With a two-part tool and the power of offset driving. He took a cylindrical chunk of steel and bored a little cup for a ball bearing to move around in. He didn’t have one rolling around his tool box, so he liberated one from a 2209 double row self-aligning cylindrical bore with a screwdriver. Then he hammered a square rod of steel into a hole in the other end and made the rod’s bottom a little bit concave on the grinding wheel. He also took a little off the sides to aid the weeble wobble action. A second steel cylinder with a ball bearing cup sits in the chuck of his Bridgeport mill and wobbles the tool bit through the power of a 1/4″ offset.

[Chris] tested it on the same sacrificial plate he used to demonstrate the awesome power of Lil’ Screwy, his 100-ton homebrew press. He drilled a 3/8″ round pilot hole and then went to work with the Wobble Drive. The tool bit side proved to be too long to provide the requisite stroke, so he cut it down by about half. Once the tool has chewed through the steel, the tool bit decouples at the ball bearing and [Chris] has himself a square hole and that much more hacking cred.

[Read more...]

Behold Lil’ Screwy, A Homebrew 100-Ton Press

Here we have a magnificent example of the power of the inclined plane. [Chris] has built Lil’ Screwy, a 100-ton home-built press for about $35 plus scrap on hand. He demonstrates its frightening power by punching a 17-mm hole through 8mm-thick steel using an Allen key.

As [Chris] explains in his hilarious video waiting for you after the jump, the force comes from using really big screws. Lil’ Screwy uses four 1-inch L7-rated ready rods with eight threads to the inch. The bolts run between two 1″ steel plates to form the press. In the top plate, he drilled 1″ holes. The bottom holes are drilled out 7/8″ and tapped so the two plates clamp together with awesome crushing power when you twist the giant coupling nuts.

[Chris] milled a pocket in the underside of the top plate for a big neodymium magnet that will keep, for instance, a 17-mm Allen key in place while you punch a piece of steel with it. He has a ring of smaller ones embedded into the bottom plate to hold supports in place for broaching.

As a special bonus, [Chris] shows you how to stick it to the man when it comes to using that last bit of Never-Seez in the can, and also how to make your decals temporarily repositionable.

[Read more...]


Get every new post delivered to your Inbox.

Join 91,149 other followers