Smart Sphere Or Magnetic Magic

June 19, 2023 by Brian McEvoy 10 Comments

Sometimes a coworker sees something on your desk, and they have to ask, “Where can I get one of those?” and that has to be one of the greatest compliments to a maker. [Greg Zumwalt] nailed it with his “Marblevator Line Follower.” Roboticists will immediately recognize a black line on a white surface, but this uses hidden mechanics instead of light/dark sensors. Check out the video after the break to see the secrets, or keep bearing with us.

Inside the cylinder is a battery, charging circuit, inductive receiving coil, and a motor turning a magnet-laden arm beneath the cap. The overall effect is an illusion to convince people that the marble has a mind of its own. You can pick up the cylinder, and it keeps moving as expected from an autonomous bot. The black line is actually a groove, so the bearing follows a curvy course without any extra movements from the magnets within. The two-tone look is super-clean, but the whimsy of a “smart bearing” makes this an all-around winner.

“Marblevator Line Follower” is not the first Marblevator we featured, and we love our bouncing-bearing baubles and music-making machines.

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Giant Bearing Is At The Heart Of A Camera Mount

June 15, 2020 by Brian McEvoy 9 Comments

We bet you have all some cool part in your bin that is just gnawing at you to build something cool. That doodad, possibly from a garage sale, surplus store, or clearance rack deserves a project fitting of its near-infinite potential. [isaac879] finally marries a giant ball bearing with his passion for photography in the form of a pan-tilt camera mount for his Canon DSLR. The problem with tossing your golden-ticket part into a project is that not everyone has a MacGuffin, or a brand new one might be bank-breakingly expensive, so he does us a favor and makes a drop-in replacement that you can print and fill with 6mm brass bbs. This sort of thing is why we love hackers.

The camera mount has the features we expect to see in a robust stepper mount, such as infinite spinning, time delay, and an Xbox controller interface. Inside the base is the industrial bearing or its plastic replica, and that wide base won’t be tipping over anytime soon. Gearing all around is of the herringbone style, of the type you find in classroom pencil sharpeners because they transfer power smoothly. Speaking of things going smoothly, we enjoyed his assembly montage where every part fits together perfectly and there is not a naughty word to be uttered. Just like real life.

If you like homemade bearings, check out this slew bearing that looks like it was made with Perler beads, and we have a self-aligning camera tripod mount for the photography buffs.

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3D Printed Tank Track Pops Together With Plastic BB For Hinge

April 20, 2019 by Donald Papp 20 Comments

3D printing is well-suited to cranking out tank tread designs, because the numerous and identical segments required are a great fit for 3D printing’s strengths. The only hitch is the need for fasteners between each of those segments, but [AlwynxJones] has a clever solution that uses plentiful hard plastic spheres (in the form of 6 mm airsoft BBs) as both a fastener and a hinge between each of the 3D printed track segments.

Each segment has hollows made to snugly fit 6 mm BBs (shown as green in the image here) which serve both as fasteners and bearing surfaces. Assembly requires a bit of force to snap everything together, but [AlwynxJones] judges the result worth not having to bother with bolts, wires, or other makeshift fasteners.

Bolts or screws are one option for connecting segments, but those are heavy and can get expensive. Segments of printer filament have been successfully used in other tread designs, though that method requires added work in the form of either pins, or heat deforming the filament ends to form a kind of rivet. This design may be a work in progress, but it seems like a promising and clever approach.

[via Reddit]

Incredible 3D Printed Overwatch Airsoft Pistol

July 30, 2018 by Tom Nardi 4 Comments

If you ever needed evidence that gamers are some of the most dedicated individuals in all of fandom, then look no further than this fantastic 3D printed recreation of the “Pulse Pistol” as featured in the immensely popular “Overwatch”. Built by the guys at [Danger Doc], this replica doesn’t just look the part, it’s also a fully functional Airsoft gun. In the detailed build video after the break, the year-long design and construction of the gun is broken down for your viewing pleasure.

Because the end goal was to make something that looked as though it came from the game itself, a lot of time was put into making sure that the externals were faithful to the digital version while still able to contain all the hardware they needed to cram in there. This is a fully auto gun, so it needed a battery and motors, as well as a way to feed the firing mechanism Airsoft BBs that didn’t require an anachronistic magazine sticking out.

They combined a off-the-shelf firing mechanism and high-capacity magazine but it took plenty of custom designed parts to get everything mated up. The magazine has a clockwork mechanism to advance the BBs which required the user to manually crank up, but this was replaced with an electric motor to make things a little more futuristic. In addition to all the LEDs on the body of the gun, there’s also an internal array of ultraviolet SMD LEDs to charge the glow-in-the-dark “tracer” BBs as they move through the magazine. In low light, this gives the shots from the gun something of a laser effect.

We’ve seen 3D printed guns from games before, but rarely with this attention to detail and engineering. Honestly, this even gives some real 3D printed guns a run for their money.

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Coming Back To Curving Bullets

June 10, 2018 by Brian McEvoy 23 Comments

What do you do when you have time, thousands of dollars worth of magnets, and you love Mythbusters? Science. At least, science with a flair for the dramatics. The myth that a magnetic wristwatch with today’s technology can stop, or even redirect, a bullet is firmly busted. The crew at [K&J Magnetics] wanted to take their own stab at the myth and they took liberties.

Despite the results of the show, a single magnet was able to measurably alter the path of a projectile. This won’t evolve into any life-saving technology because the gun is replaced with an underpowered BB gun shooting a steel BB. The original myth assumes a firearm shooting lead at full speed. This shouldn’t come as any surprise but it does tell us how far the parameters have to be perverted to magnetically steer a bullet. The blog goes over all the necessary compromises they had to endure in order to curve a bullet magnetically and their results video can be seen below the break.

Here we talk about shooting airplane guns so they don’t get mislead after leaving the barrel, and some more fun weaponry from minds under Churchill’s discretion.

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Pneumatic Pen Gun Is Fit For James Bond

May 15, 2015 by Rick Osgood 53 Comments

The James Bond franchise is well-known for many things, but perhaps most important to us hackers are the gadgets. Bond always had an awesome gadget that somehow was exactly the thing he needed to get out of a jam. [hw97karbine’s] latest project would fit right into an old Bond flick. He’s managed to build a single-shot pellet gun that looks like a pen.

[hw97karbine] started out by cutting the body from a tube of carbon fiber. He used a hacksaw to do the cutting, and then cleaned up the edges on a lathe. A barrel was cut from a piece of brass tubing with a smaller diameter. These two tubes will eventually sit one inside of the other. A custom front end cap was machined from brass. One end is ribbed and glued into the carbon fiber tube. The barrel is also glued to this end of the front cap, though it’s glued to the inside of the cap. The other end of the cap has 1/8″ BSP threads cut into it in order to allow for attachments.

A rear end cap is machined from Delrin. This piece also has a Delrin piston placed inside. The piston has a small piece of rubber used as a gasket. This piston valve is what allows the gun to operate. The rear cap gets glued into place and attached to a Schrader valve, removed from an automotive tire valve stem.

To pressurize the system, a bicycle pump is attached to the Schrader valve. This pushes the piston up against the barrel, preventing any of the air from escaping. The piston doesn’t make a perfect seal, so air leaks around it and pressurizes the carbon fiber tube. The Schrader valve prevents the air from leaking out of the pen body. A special machined button was threaded onto the Schrader valve. When the button is pressed, the air escapes; the sudden pressure imbalance causes the piston to shoot backwards, opening up a path for the air to escape through the barrel. This escaping air launches the projectile. The whole process is explained better with an animation.

Now, the question left in our mind: is this the same pressure imbalance concept that was used in that vacuum pressure bazooka we saw a couple years back?

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Fail Of The Week: [Chris] Vs. The Gorn

October 16, 2014 by Kristina Panos 30 Comments

This week, [Chris] tips the scales but ultimately fails. He’s on the road, hacking through the Great White North and improvising from a poorly-lit echo chamber that happens to have a vise.

Knowing nothing about firearms (do you believe that?), he decided to build a BB cannon out of pure scrap. Several kinds of sparks fly, starting with a Hitachi drill-as-lathe and ending with a tiny cupcake sparkler. [Chris] proceeds to bore out some redi-rod by eyeballing it and offers helpful tips for course correction should you attempt same. Having centered the cavity, he drills out a tiny hole for a fuse.

His first fuse is of the crushed up match head paste variety. It burns kind of slowly and does not launch the BB. Naturally, Plan B is to make napalm glue to adhere Pyrodex pistol powder to paper. As you might imagine, it worked quite well. The wadding was singed, but still no joy. After packing her full of propellant, it still didn’t explode and merely burned out the blowhole. So, what gives? Insufficient barrel length? Should have used bamboo instead of redi-rod? Didn’t want it badly enough? Give us your fodder below.

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