An Exoskeleton Arm For A Hacker On A Budget

Whether it is motivated by a dream of superhuman strength courtesy of a mech suit or of mobility for those with impaired muscle function, the powered exoskeleton exerts a curious fascination among engineers. The idea of a machine-augmented human body achieving great things is thwarted though by the difficulty of the task, actuators and power sources small enough to be worn comfortably represent a significant challenge that is not easily overcome. It’s a subject that has captivated [Kristjan Berce] since at a young age seeing his grandmother struggling with lifting, and he presents a working powered exoskeleton arm as a proof of his ideas.

It’s a wonderful exercise in low-tech construction with hand tools and a drill press on pieces of aluminium and wood. Motive power comes from an automotive windscreen wiper motor, and electrical power comes from a hefty LiPo attached to the device’s harness. There is a feedback potentiometer incorporated into the elbow joint, and an Arduino oversees the operation under the direction of a pair of glove-mounted buttons. It’s certainly impressive to see it in the video below lifting a bicycle, though we wonder how its weight might affect someone with less muscle function than average.

Projects like this one are very good to see, because there’s a chance that somebody out there may be helped by building one of these. However there is always a note of caution to be struck, as the best solutions come from those who need them and not those who merely think they have the solution. We have written about the Engineer Saviour Trap here in years past.

This isn’t the first prosthetic arm we’ve seen though, we covered a hackerspace in England printing one for a local youngster.

Continue reading “An Exoskeleton Arm For A Hacker On A Budget”

Can This Fire Fighting Robot Take The Heat?

Firefighting is a difficult and dangerous job, which puts humans on the front line to save life and property on a regular basis. It’s a prime candidate for some robot helpers, and [Ivan] has stepped in with a fun build that, while it won’t be serving in your municipal department any time soon, gets us thinking about the possibilities.

It’s a radio controlled robot with an Arduino Uno for the brains. A couple of motor driver boards are used to run four windscreen wiper motors for propulsion. Long before the days of online shopping, the wiper motor was a hacker staple – a cheap, readily available high torque motor that could be easily driven for a range of hobby projects. They say only 90’s kids remember.

As far as water delivery goes, this robot is a little short on credentials, carrying only 1 litre of water. However, we appreciate [Ivan]’s use of a Tupperware container as a tank – with a few add-on fittings, this could be a great way to hold water in other projects. The small DC-powered pump is controlled by an industrial solid state relay – a good choice for a robot that may get wet. There’s an onboard CO2 extinguisher as well, but it’s sadly not plumbed into anything just yet.

This build is an [Ivan] classic – big, fun, and 3D printed on a much larger scale then we’re used to. It’s a strong  follow up to his impressive tank build we saw earlier. Video after the break.

[Thanks to Baldpower for the tip!]

Continue reading “Can This Fire Fighting Robot Take The Heat?”

A 3D-Printed Coffee Grinder

It’s safe to say that a Venn diagram of Hackaday readers and coffee drinkers would have significant intersection, many of you will be lovers of the bean. Some of you will be happy enough with a spoonful of instant granules and a bit of boiling water, but among your number there will undoubtedly be owners of significant quantities of coffee-related machinery and paraphernalia.

If your coffee enthusiasm extends to grinding your own direct from the bean, then [Christian Pederkoff]’s project should hit the mark, he’s created a rather neat 3D-printed coffee grinder. Sadly the creation of a steel burr and ring was beyond his 3D-printing capabilities so those parts come from a commercial grinder, but the housing, shaft coupler and hopper are all from his printer. Power is from a conveniently available source, he’s made use of an automotive windscreen wiper motor. The whole is a straightforward and easy-to-assemble unit that we think would sit well alongside many readers’ coffee making equipment.

If coffee projects are your thing, we have a few for your entertainment. Another not quite so neat enclosure for a coffee grinder, for example, or a tea-light-powered filter coffee machine for power cut beverage satisfaction.

The Almost Useful Machine

[Alex] is no stranger to making machines of negligible utility. A few years ago he made the Almost Useless Machine, a solar-powered system that cuts through a 20mm dowel rod while you wait (and wait, and wait). Enamored by the internet’s bevy of powered hacksaws, he sought to build a sturdier version that’s a little more useful. Approximately five months of free time later, he had the Almost Useful Machine.

It runs on a wiper motor and a recycled power supply from a notebook computer. [Alex] rolled his own board for controlling the motor with an ATtiny25. The circuit turns potentiometer movement into PWM, which controls the motor through a MOSFET. After the cut is finished, an endstop microswitch  immediately cuts the motor.

Every bit of the chassis is aluminum that [Alex] machined by hand. Don’t have that kind of setup? How about a powered hacksaw with a 3D-printed linkage? Make the jump to see it in action, and stick around for the two-part time-lapse build video.

Continue reading “The Almost Useful Machine”