showing the ramp and sprayer of the cider press

The Spiced (Cider) Must Flow

A fresh-squeezed glass of orange juice with breakfast seems like a trope that’s straight from a late 1980s sitcom. Making orange juice is easy; press until the liquid comes out. Apple juice (and, by extension, apple cider) is the same principle but requires much more force to squeeze out the juice. So what if you, like [Peter], have 900 lbs (408.2 kg for those metrically minded) of apples that you want to make cider out of? The obvious solution is to create a somewhat automated homemade cider press with lasers.

An earlier effort to make 25 gallons of cider took several full days of struggle for four people, so [Peter] knew he had to plan better next year. [Peter’s wife] milled and glued red oak into a large, sturdy frame that could press down with proper force and not break. [Peter] reached out to the local metal shop to fabricate a stainless steel tray with a custom drain. The cider basket itself and the pressboard were maple with waterproofing oil.

However, just because you can press apples, doesn’t mean you’re ready to make cider. They still need to be washed, cut, and ground into a pulp. A ramp was fashioned that it could be set in a truck bed with sprayers to wash the apples as they rolled by. A laser circuit with an LM393 opamp and a photoresistor allowed the sprayers to only activate when there was actually an apple to spray. Apple grinders are tricky as they need to survive the drop of several one-pound balls while staying at a reasonable speed. The grinder dispenses the pulp into a mesh nylon bag in a 5-gallon bucket, ready to be pressed. For the curious reader, 900lbs of apples yielded 60 gallons of delicious cider.

If you’re looking for a smaller scale press, here’s a cider press that’s a little simpler to make.

Building A Stump Grinder From The Ground Up

Felling a tree properly is a skill that takes some practice to master, especially without causing any injuries or property damage. Getting the tree cut down though is sometimes only half of the battle, as the stump and roots need to be addressed as well. Unless you have a few years to wait for them to naturally decompose you might want to employ a stump grinder, and unless you want to spend a chunk of money on a stump grinding service or buy your own, you might want to do what [Workshop from Scratch] did and build your own.

This stump grinder isn’t anything to scoff at, either, and might even fool some into thinking it’s a consumer grade tool from a big box store. Far from it though, as almost everything down to the frame is custom machined specifically for this build. The only thing that isn’t built from scratch, including the cutting wheel, is the beefy 15 horsepower motor. Once it gets going it is able to carve stumps down to the ground in no time thanks especially to some gear reductions in the drive line from the motor to the cutting head.

Before anyone mentions safety, it looks like [Workshop from Scratch] has made some upgrades since his last project which was a gas-powered metal cutting chainsaw. Since then it looks like he has upgraded the sheet metal to something a little thicker, even though a stump grinder has arguably lower risk due to the slower speed of the cutting wheel and also to the fact that the cutting medium is wood and not metal. There are also brakes and an emergency shutoff switch. It sure seems like a fine addition to his collection of completely custom tools.

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Chainsaw Cuts More Than Timber

We often take electricity for granted, to the point of walking into a room during a power outage and still habitually flipping the light switch. On the other hand, there are plenty of places where electricity isn’t a given, either due to poor infrastructure or an otherwise remote location. To get common electric power tools to work in areas like these requires some ingenuity like that seen in this build which converts a chainsaw to a gas-driven grinder that can be used for cutting steel or concrete. (Video, embedded below.)

All of the parts needed for the conversion were built in the machine shop of [Workshop from scratch]. A non-cutting chain was fitted to it first to drive the cutting wheel rather than cut directly, so a new bar had to be fabricated. After that, the build shows the methods for attaching bearings and securing the entire assembly back to the gas-powered motor. Of course there is also a custom shield for the grinding wheel and also a protective housing for the chain to somewhat limit the danger of operating a device like this.

Even though some consideration was paid to safety in this build, we would like to reiterate that all the required safety gear should be worn. That being said, it’s not the first time we’ve seen a chainsaw modified to be more useful than its default timber-cutting configuration, like this build which turns a chainsaw into a metal cutting chop saw.

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Retrotechtacular: Shake Hands With Danger

OK, you’re going to have to engage your safety squints and sit back to enjoy this one: a classic bit of safety propaganda from US heavy-equipment manufacturer Caterpillar from 1980 entitled “Shake Hands with Danger.”

Actually, you’ll probably need to engage your schlock filters for this 23-minute film too, as both the writing and the theme song are pretty hard to take. The film is one of those “Scared Straight” attempts to show just how horrifically wrong things can go both in the field and in the shop when working on anything made of stuff stronger than human flesh and bone. And in that regard, the film is highly effective — we found ourselves getting a bit queasy at a few points, with the poor dude who got his hand sucked into a bench grinder being both terrifying and relatable. [Three-Finger Joe] indeed.

Now, you might take exception with the acting, but as you watch all these vignettes, keep in mind that these are all old-school stunts — that’s actually a gigantic D9 bulldozer they crashed, and that brake chamber explosion really blew out that truck’s windows. They did a great job making the potential consequences of a moment’s thoughtlessness sickeningly vivid. Especially that arm-in-the-linkages scene. Ugh.

Whatever way you practice the hacking arts, stay safe out there. And don’t “Shake Hands with Danger.”

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Open-Source Grinder Makes Compression Screws For Plastic Extruders Easy

In a world that’s literally awash in plastic waste, it seems a pity to have to buy fresh rolls of plastic filament to feed our 3D-printers, only to have them generate yet more plastic waste. Breaking that vicious cycle requires melding plastic recycling with additive manufacturing, and that takes some clever tooling with parts that aren’t easy to come by, like the compression screws that power plastics extruders.

This open-source compression screw grinder aims to make small-scale plastic recyclers easier to build. Coming from the lab of [Joshua Pearce] at the Michigan Technological University in collaboration with [Jacob Franz], the device is sort of a combination of a small lathe and a grinder. A piece of round steel stock is held by a chuck with the free end supported by bearings in a tailstock. On the bed of the machine is an X-Y carriage made of 3D-printed parts and pieces of electrical conduit. The carriage moves down the length of the bed as the stock rotates thanks to a pulley and a threaded rod, carrying a cordless angle grinder with a thick grinding wheel. A template attached to the front apron controls how deep the grinder cuts as it tracks along the rod; different templates allow the screw profile to be easily customized. The video below shows the machine in action and the complicated screw profiles it’s capable of producing.

We’ve seen lots of homebrew plastic extruders before, most of which use repurposed auger-type drill bits as compression screws. Those lack the variable geometry of a proper compression screw, so [Joshua] and [Jacob] making all the design documents for this machine available should be a boon to recycling experimenters.

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High-Precision Air Bearing CNC Lathe And Grinder

You know you’re in for a treat when you are told that a lathe which can reach a resolution of one micrometer (1×10−6, a millionth of a meter, or 0.00004″ for people who love zeros) is ‘not hard to build’.  This is one of the opening statements in this video by [Dan Gelbart], as he walks the viewer through the details of a custom CNC lathe which he built. (Video embedded below.)

As it’s a combined CNC lathe and grinder, it uses custom software he had developed specifically for the machine. Much of the high precision of the machine is courtesy of air bearings. All but two of the air bearings were made by [Dan], with the two surplus air bearings he used coming from machines used in the semiconductor industry.

The bed of the machine is formed out of off-the-shelf reference granite, to which the other parts are epoxied, providing a stable base with well-defined dimensions. Though perhaps a few light years beyond most DIY lathe efforts, [Dan]’s videos nevertheless provide a treasure trove of tips and information for lathe builders and users alike. Certainly worth a look.

Thanks [Drew] for the tip in the comments.
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Pegleg: Raspberry Pi Implanted Below The Skin (Not Coming To A Store Near You)

Earlier this month, a group of biohackers installed two Rasberry Pis in their legs. While that sounds like the bleeding edge, those computers were already v2 of a project called PegLeg. I was fortunate enough to see both versions in the flesh, so to speak. The first version was scarily large — a mainboard donated by a wifi router roughly the size of an Altoids tin. It’s a reminder that the line between technology’s cutting edge and bleeding edge is moving ever onward and this one was firmly on the bleeding edge.

How does that line end up moving? Sometimes it’s just a matter of what intelligent people can accomplish in a long week. Back in May, during a three-day biohacker convention called Grindfest, someone said something along the lines of, “Wouldn’t it be cool if…” Anyone who has spent an hour in a maker space or hacker convention knows how those conversations go. Rather than ending with a laugh, things progressed at a fever pitch.

The router shed all non-vital components. USB ports: ground off. Plastic case: recycled. Battery: repurposed. Amazon’s fastest delivery brought a Qi wireless coil to power the implant from outside the body and the smallest USB stick with 64 GB on the silicon. The only recipient of PegLeg version 1.0 was [Lepht Anonym], who uses the pronoun ‘it’. [Lepht] has a well-earned reputation among biohackers who focus on technological implants who often use the term “grinder,” not to be confused with the dating app or power tool.

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