A Capable Nerf Launcher Robot

July 12, 2021 by Lewin Day 5 Comments

Nerf blasters are fun to play with, and it’s now possible to even get robotic Nerf launchers you can use to chase around your friends. [Engineering After Hours] wasn’t satisfied with the official hardware, though, so built his own remote control Nerf rig to battle it out in the back yard.

The rig is built around an earlier build from [Engineering After Hours], a skid-steer RC chassis that is nice and tough to handle rough and tumble driving. It’s paired with a trailer attached to the center of rotation of the chassis that makes the pair highly maneuverable.

In order to launch rockets, an air tank on the trailer is hooked up to some piping to launch four Nerf rockets. Charged up to just 40 psi, it’s capable of launching the rounds with plenty of power for play purposes. Paired with a elevation control and a servo to trigger the firing valve, it’s a complete system that can shoot on the go.

It’s a fun build that packs a punch, even if it doesn’t quite have the accuracy or range you might desire in an all-conquering Nerf combat platform. We’d love to see a similar build hooked up to some AI smarts to stalk targets independently of human control. Video after the break.

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Building A Big Ol’ Powerful Wheelbarrow

July 10, 2021 by Lewin Day 16 Comments

Sometimes you’ve gotta haul big heavy loads around a wide area. Regular wheelbarrows are fine, but it can quickly grow tiring when one has to make multiple trips. [Workshop from Scratch] instead elected to build a powered wheelbarrow, with plenty of grunt to shift loads about.

The build is absolutely from the ground up, welded up from sections of steel RHS, and given rear steering for plenty of maneuverability. The actual job of steering is handled by a rack repurposed from automotive use, set up with a single-sided attachment to the rear wheel assembly. It’s quite a neat and tidy way of doing the job, and seems to work well. Drive is sent to the front wheels through a hydrostatic lawnmower transmission. A 17-horsepower engine provides plenty of grunt for the job at hand, even coming with electric start already fitted for the ultimate in ease-of-use.

It’s impressive to see just how much of the rig was put together from raw materials; even the fuel tank was fabricated in steel. We’ve seen similar builds from [Workshop from Scratch] before, like this tidy bandsaw. Video after the break.

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Reverse Engineering A Very Cheap Fitness Band

July 8, 2021 by Lewin Day 10 Comments

With the rise of big-name smartwatches in the marketplace, there are also a smattering of lower-end offerings. The M6 fitness band is one of them, and [Raphael] set about hacking the cheap device with a custom firmware of his own creation.

The M6 band, which sells for around $6, appears to trade on name similarity to the more expensive (~$50) Xiaomi Mi Smart Band 6 fitness tracker. Upon disassembly, [Raphael] found that the system-on-chip running the show is a Telink TLSR8232. It’s paired with a 160×80 display, a small LiPo battery for power, and a vibration motor and what appears to be a fake heart rate sensor.

[Raphael] wanted to flash the SOC with a new firmware, and learned a lot from code for a similar part created by [atc1441]. It took some time to figure out how to program the chip using the somewhat oddball SWire interface, but [Raphael] persevered and eventually got things going after much research and experimentation.

From there, it was yet further work to figure out how to read the capacitive button input as well as how to drive the screen, but [Raphael] succeeded in the end. The final result was whipping up a firmware that allowed him to read Bluetooth Low Energy soil moisture sensors he has installed in his plants at home.

It’s not [Raphael], aka [rbaron]’s first bite at the cherry; we’ve featured his efforts in hacking similar fitness bands before! Video after the break.

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A Plastic Injection Machine You Can Use At Home

July 7, 2021 by Lewin Day 25 Comments

3D printing is all well and good if you want one of something, but if you want lots of plastic parts that are all largely identical, you should consider injection molding. You can pay someone to do this for you, or, in true hacker fashion, you can build an entire injection molding setup in your own garage, as [Action BOX] did.

The build relies on a pair of beefy 3hp motors to drive the screw-based injection system. These are responsible for feeding plastic pellets from a hopper and then melting them and filling the injection reservoir, before then forcing the hot plastic into the mold. Further stepper motors handle clamping the mold and then releasing it and ejecting the finished part. A Raspberry Pi handles the operation of the machine, and is configured with a custom Python program that is capable of proper cycle operation. At its peak, the machine can produce up to 4 parts per minute.

It’s an impressive piece of industrial-type hardware. If you want to produce a lot of plastic things in your own facility, a machine like this is very much the way to go. It’s not the first machine of its type we’ve seen, either! Video after the break. Continue reading “A Plastic Injection Machine You Can Use At Home” →

How To Make A Collapsible Container Without Breaking Down

July 5, 2021 by Kristina Panos 5 Comments

How hard could it be to make a collapsible silicone container? Turns out, it’s really, really hard — collapsible containers have rigid guidelines. Just ask [Eric Strebel], who failed dozens of times before finally getting it right (video, embedded below).

[Eric] started with an SLA-printed two-part mold and a silicone formulation with a Shore durometer of A 40 — this is the measure of hardness for silicone, polymers, and elastomers in the sense that the piece will resist indentation. The first twenty-four attempts all came out looking great, but not a single one of them would collapse and stay collapsed.

Eventually, [Eric] went back to the drawing board and played with the angles of the flex points, the thickness of the living hinges, and the wall thicknesses, which have to be strong enough to stay collapsed.

For attempt #25, [Eric] took the part out of the mold about three hours in and tried curing it in the collapsed state. Persistence paid off, and the part finally collapses and stays that way. Get yourself some popcorn and check out the fail-fest after the break. You know what we always say — fail fast, fail often.

[Eric] has made many molds both from silicone and for silicone. Some of them are really big!

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Extreme Canine Mask For Protection From Foxtails

July 4, 2021 by Danie Conradie 33 Comments

Our canine partners are fortunately not affected by the current global pandemic, but it turns out there are other dangers that might necessitate them to wearing masks: Foxtail seeds. After getting a $400 vet bill for extracting a foxtail from his dog, [Hildeguard]’s ear, [Amos Dudley] decided to take the threat seriously and made her a form-fitting 3D printed mask.

The only commercial solution [Amos] could find was the “OutFox Field Guard”, which is a $50 vinyl-coated mesh bag that covers the dog’s entire head. It had the unfortunate side effects of causing some other dogs to try and rip it off and does not allow easy access to the mouth for treats or balls. [Hilde]’s custom mask was designed in CAD after creating a rough 3D scan of her head with an iPhone app. The bottom is open to allow [Hilde] to freely use her mouth, while the nose and ears holes are covered with mesh. Custom heat-formed polycarbonate lenses cover the eye holes. The mask itself was printed using Draft resin, and the inside was padded with a thin layer of foam. It might also be possible to create a silicone version using a 3D-printed mold. The top features an integrated GoPro mount, and we can’t help but wonder what other electronic upgrades could be fitted to this sci-fi-looking mask.

In the field, the mask worked well and did not seem to bother [Hilde]. Unfortunately, it did not solve the problem of other dogs trying to rip it off at the park, so for the moment [Amos] is only using it for more solitary activities like hiking.

It doesn’t look like [Amos] is struggling in that department, but if you need some help burning of your dog’s energy, you can always built them a 3D printed automatic ball launcher.

3D Zoetrope Uses Illusion To Double The Frames

July 3, 2021 by Kristina Panos 10 Comments

Although film and animation have come quite a long way, there’s still something magical about that grandaddy of them all, the zoetrope. Thanks to persistence of vision, our eyes are fooled into seeing movement where there is none, only carefully laid-out still pictures strobing under the right lighting.

After four months of research, CAD, prototyping, and programming, [Harrison McIntyre] has built a 3D zoetrope that brings a gif to glorious physical life (video, embedded below). All the image pieces are printed and move under a fancy backlight that [Harrison] borrowed from work. It works essentially the same as a 2D zoetrope, as long as you get the spacing juuuuust right. 360° divided by 20 frames comes out to 18° per frame. So a motor spins the disk around, and every 18°, the light pulses for one millisecond and then turns off until the next frame is in position.

The really interesting thing is that there are actually more than 20 frames at play here. If you follow a single character through the loop, it takes 46 frames to complete the animation thanks to something 3D zoetrope pioneer [Kevin Holmes] dubbed ‘animation multiplexing‘, which in [Harrison]’s example, is easily explained as a relay race in which all runners run their section at the same time, creating the illusion of constant motion.

There’s more than one way to use a 3D printer to create a zoetrope, and we doubt we would have ever thought of this one that squashes four dimensions into three.

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