diy air compressor

DIY Air Compressor Made From Refrigerator And Fire Extinguisher

[Giorgos] wanted to build a pneumatic solder paste application tool but needed an air compressor to power it. Instead of going out and buying a compressor, he decided to build one himself. It sure is an ugly duckling but we’re impressed with it’s performance.

The air tank is an old spent fire extinguisher. The stock valve was removed and the insides were cleaned out. Out of curiosity, [Giorgos] figured out the volume by filling the tank with water, then measuring how much water came out. It turned out to be 2.8 liters. Two holes were drilled and threaded bungs were welded on to attach inlet and outlet lines.

The compressor portion is straight out of a refrigerator. Besides the compressor being free, the other benefit is that it is super quiet! Check the video after the break, you’ll be astonished. [Giorgos] did some calculations and figured out that his solder paste applicator needed about 8 bar (116 psi) of pressure. The refrigerator compressor easily handles that, filling the tank in 1 minute, 25 seconds.

On the output side of the tank resides a pressure switch for automatically filling the tank and a regulator for ensuring the solder paste applicator gets the required pressure. This isn’t the first time we’ve seen a refrigerator compressor used as an air compressor. Check out this dual setup capable of 400 psi.

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Hacking A $100 Signal Generator

Signal generators are a useful piece of kit to have on your electronics bench. The downside is that they tend to be rather expensive. If you have $100 to drop on a new toy, the MHS-5200A is a low cost, two channel, 25 MHz generator that can be found on eBay.

The downside is the software. It’s an ugly Windows interface that’s a pain to use. The good news is that [wd5gnr] reverse engineered the protocol so you don’t have to. This means other software can be developed to control the device.

When connected to a computer, this function generator shows up as a virtual USB serial port. The documentation that [wd5gnr] assembled lists all the serial commands you can send, and what they do. If you aren’t into manually setting waveforms from a serial terminal (who is?) there’s a tool for doing that automatically on Github. This takes in a CSV file describing a waveform, and programs the generator to make it for you.

The software is also compatible with Waveform Manager Plus, a free GUI tool for defining waveforms. Putting this all together, you can have a pretty capable waveform generator for less than $100.

2D Printed Tachometer For A Lathe

If you ever wanted a reason to have DC lighting pointed at the spinny part of your mill and lathe, [Bill] tells a great story. One day, he noticed the teeth on his lathe chuck would change color – red, then blue, then red. His conclusion was the fluorescent lights above his workbench was flashing, as fluorescent lights normally do.

Imagine if the teeth on [Bill]’s chuck weren’t painted. They would appear stationary. That’s usually a bad thing when one of the risks of using a lathe is ‘descalping.’ Buy an LED or incandescent work light for your shop.

This unique effect of blinking lights got [Bill] thinking, though. Could these fluorescent lights be used as a strobe light? Could it measure the RPM of the lathe?

And so began [Bill]’s quest for a 2D printed lathe tachometer. The first attempt was to wrap a piece of paper printed with evenly space numbers around the chuck. This did not work. The flash from his fluorescent bulb was too long, and the numbers were just a blur. He moved on to a maximum-contrast pattern those of us who had a ‘DJ phase’ might recognize immediately.

By printing out a piece of paper with alternating black and white bands, [Bill] was able to read off the RPM of his chuck with ease. That’s after he realized fluorescent lights blink twice per cycle, or 120 times a second. If you have a 3″ mini-lathe, [Bill] put the relevant files up, ready to be taped to a chuck.

Custom Downdraft Fume Extractor for Soldering

Downdraft Fume Extractor Saves Your Lungs

When you’re soldering, smoke rises from your iron. That smoke is full of a variety of chemicals, depending on what type of solder you’re using, but it’s almost certainly not good for you. That’s why you can buy fume extractors to suck smoke away.

But benchtop extractors tend to suck, and not in the way they’re supposed to. It can be hard to get the extractor to pick up all the fumes, leaving fumes that float into your face.

Over at Other Machine Co., they built up a custom downdraft fume extractor to solve this problem. The downdraft extractor is a table that you work on, providing downwards suction that grabs the fumes. Their table uses a standard MERV13 air filter that’s rated to trap particles as small as 1.0–0.3 μm. Cooling fans provide the airflow, and a piece of perforated sheet metal acts as a work surface.

The table works great for soldering, and is also helpful for working with other chemicals like adhesives and solvents. DXF files for the frame parts are provided, and everything else can be sourced from McMaster.

Hacklet 53 – Quick Tool Hacks

They say necessity is the mother of invention. Have you ever been right in the middle of a project, when you realize that you could hack up a simple tool which would make your current task easier? Maybe it’s a coil winder, or a device to hold .100 headers straight in their holes. Faster than you can say “Arabian Nights”, you’re working on a project within a project. It might not be pretty, but it gets the job done. This week’s Hacklet is all about quick tool hacks – little projects that help out around the shop or hackerspace.

lampieWe start with [theonetruestickman] and Magnificent Magnifier LED Coversion. [theonetruestickman] picked up an articulated magnifier lamp at Goodwill for $4. These lamps are a staple of benches everywhere. The only problem was the switch and fluorescent tube were both failing. [theonetruestickman] didn’t feel bad for the lamp though. He pulled out the tube, ballast, and starter, replacing them with LEDs. He used 12 V 3 watt LED modules to replace the tube. Three modules provided plenty of light. An old wall wart donated its transformer to the effort. Since these LED modules are happy running on AC, no bridge rectifier was necessary. The modernized lamp is now happily serving on [theonetruestickman’s] workbench.

toolNext up is [Kwisatz] with Pick Up tool hack. [Kwisatz] is a person of few words. This whole project consists of just two words. Specifically, “syringe” and “spring”. Thankfully [Kwisatz] has provided several pictures to show us exactly what they’ve created. If you’ve ever used one of those cheap pickup tools from China, you know [Kwisatz’s] pain. The tiny piece of surgical tube inside the tool creates a feeble vacuum. These tools only hold parts for a few seconds before the vacuum decays enough to drop the part. [Kwisatz] kept the tip of the tool, but replaced the body with a syringe. A spring is used to create just the right amount of vacuum to hold parts on while they are being placed.

fume[Dylan Bleier] made his shop air a bit safer to breathe with a simple fume extractor for $20. Solder and flux create some nasty smoke when heated. Generally that smoke wafts directly into the face of the hacker peeking at the 0402 resistor they are trying to solder. A bit of smoke once in a while might not be so bad, but over the years, the effects add up. [Dylan] used two 120V AC bathroom fans, some metal ducting, plywood, and a bit of time to make this fume extractor. [Dylan] is the first to say it’s not UL, CE, or ROHS compliant, but it does get the job done. He even added a screen to keep bugs from flying in from the outdoor exhaust port.

helix[ftregan] needed to wind a helical coil for an antenna, so he built Helix Winder. Helices are essentially springs, so that should be easy, right? Turns out that making a nice uniform helix is not the easiest thing in the world. The helix winder is a jig which makes winding these special coils much easier. Holes are drilled at a specific angle in a wooden block. The wire is fed through that block and rolled onto an aluminum tube. Rotating the block on the tube forces the wire into the helix shape. The only downside is that each winder is only good for once dimension of helix.

I’ve noticed that some of these quick hacks don’t get as much love as they deserve over on hackaday.io. So if you notice a cool hack like this, drop a comment and give the project a skull. If you want to see more of these hacks, check out our new quick tool hacks list! See a project I might have missed? Don’t be shy, just drop me a message on Hackaday.io. That’s it for this week’s Hacklet, As always, see you next week. Same hack time, same hack channel, bringing you the best of Hackaday.io!

Machine Metal With Electricity: An EDM Attachment For 3D Printers

[SuperUnknown] has revealed a secret project he’s been working on. He’s cooked up an EDM attachment for 3D printers, or any CNC machine for that matter. Electrical Discharge Machining (EDM) is a method of using sparks to machine metal. EDM isn’t a new technology, in fact commercial machines have been around since the 1960’s. If you’ve ever had an arc scar up your multimeter probes, you’ve unwittingly done a bit of EDM.

The theory behind EDM is simple: High voltage between the tool and workpiece causes sparks to jump between them. Each spark erodes the workpiece (and the tool). Big EDM machines perform their magic in a liquid which acts as both a dielectric and a flushing medium. This liquid can be anything from deionzed tap water to specially formulated oil. [SuperUnknown] is using good old-fashioned tap water.

edm-roughAs you can imagine, a single spark won’t erode much metal. EDM machines fire tens of thousands of times per second. The exact frequencies, voltages, and currents are secrets the machine manufacturers keep close to their chests. [SuperUnknown] is zeroing in on 65 volts at 2 amps, running at 35 kHz. He’s made some great progress, gouging into hardened files, removing broken taps from brass, and even eroding the impression of a coin in steel.

While we’d love to say this is a free open source project, [superUnknown] needs to pay the bills. He’s going with crowdsourced funding. No, not another Kickstarter. This project is taking a different route. The videos of the machine will be uploaded to YouTube and visible to [superUnknown’s] Patreon supporters. They will also be available for rent using YouTube’s new rental system. [SuperUnknown] has pledged to figure out a way to make the content available for starving college students and others with limited incomes.

Based upon his previous adventures with lil’ screwy, his homemade 100 ton press, and various other projects on the Arduino verses Evil YouTube channel, we think [superUnkown] has a pretty good chance of making home EDM work. Click past the break to see two videos of the 3D printer EDM toolhead in action. We should mention that [SuperUnknown] is rather colorful with his dialogue, so make sure you’re using headphones if you’re at work.

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Crawlspace Warehouse Includes Midget Forklift

Meet [Cliff Stoll], producer and entrepreneur-extraordinaire of the ACME Klein Bottles. Years back he helped a friend program a glass oven to get the right temperature profiles for glass blowing. When asked how he wanted to get paid for his help, he asked if they could blow a Klein bottle — and so they did.

Excited at the prospect of his creation, he showed it around to some friends, and was surprised to find out that people wanted to buy it! The one he created took 3 days of sweat and tears to build, so he wasn’t about to start manufacturing them himself. Instead, he decided to call around to some glass manufacturers and see how much he could get Klein bottles made for… That’s when he discovered the power of buying in large quantities.

So what do you do with over 1000 Klein bottles? You build a mini-warehouse in your crawlspace — that’s what.

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