Building a linear motor


We admit that this project doesn’t have very many details available, but it was just too neat for us to pass up. It’s a small linear motor which [ligonapProduktion] built after seeing a very brief description of a commercially available version.

The video after the break shows him testing the motor. In this screenshot he’s holding the center shaft while the coil assembly moves back and forth. But it works with a stationary coil moving the rod as well. The motor is basically a modified solenoid. There are sixteen neodymium magnets inside the shaft. The set of four coils is driven by an ATtiny44. Just like a stepper motor, energizing the coils in the correct order pushes against the rare earth magnets creating motion.

We’re not sure if he has any use in mind for this build. For us we just like to see the concept in practice (we feel the same way about a homopolar motor build).

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Enhance your magnetic silly putty with personal lubricants


Instructables user [killbox] seems to have come across a process that actually makes magnetic silly putty “better”, depending on your specific needs. He had tons of fun making a batch of magnetic putty, but thought that the addition of iron oxide made it stiff and a bit slow moving for his tastes.

He tried to find a household item that could act as silly putty thinner, but after trying various oils, gylcerin, and rubbing alcohol, he came up empty handed. Undeterred, he researched how silly putty itself is made, and based on its list of ingredients, decided to seek out some sort of silcone-based lubricant.

He headed out to the local sex shop, and spent some time browsing through the “personal lubricant” section, in hopes of finding what he needed. He settled on ”Gun Oil”, a silicone lubricant that also contained Dimethicone, an item on the ingredient list of the lubricant he initially used to make the batch of magnetic putty.

After adding the lubricant, he found that the putty retained its texture, but flowed far more easily. The thinner putty also consumes rare earth magnets more quickly than its unaltered brethren, as you can see in the picture above.

We’re not sure how far you could push the ferro-putty before it would become a mess, but it’s certainly warrants further experiments.

[Thanks, Mike]

Magnetism makes silly putty fun again

The image above is a screen capture from a video clip where the black ooze gobbles up that rare-earth magnet. It’s actually a blob of Silly Putty which was slightly altered to add magnetic properties. [Mikeasaurus] grabbed some ferric iron oxide powder from an art supply store and donned gloves and a dust mask while massaging it into the silicone polymer. If you get the right mix of the two materials you end up with a flowing substance that performs mysteriously when exposed to a magnetic field.

Check out the video after the break to see some of the tricks that [Mikeasaurus] can do. The putty really looks like it has a life of its own. It will stretch a remarkable distance to get close to the magnets (amorphous stretch). If left in contact with one it will fully engulf it and then form an orb.

Now, is there any way to use this with electromagnetic fields to build a morphing robot?

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Hand-cranked magnet machine is endless fun


We can’t think of a single person who doesn’t enjoy playing with a handful of rare earth magnets now and again. We know that [Dave Johnson] certainly does. As a gift to his father in law, he constructed a magnificent machine that does little more than manipulate spherical rare earth magnets with hypnotizing grace.

The machine is constructed almost entirely from wood, save for a few fasteners and rods. Even the gears have been carefully cut from wood, with special attention paid to ensure smooth operation. When cranked, the machine slices off a single magnet from one end of a long chain, passing it along to a lift arm. The lift arm deposits the magnet into a metal tube, and with the help of eddy currents, it drifts slowly down before being redeposited at the end of the magnet chain.

Be sure to check out a video demonstration of the machine after the break, it really is fun to watch.

[via LaughingSquid]

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