DIY Foam Cutter Makes It Too Easy

January 26, 2014 by James Hobson 39 Comments

Cutting foam is pretty tricky without a hot wire cutter. Don’t have one? Well, lucky for you, [Darcy Whyte] has a guide on how to make one. It takes just over an hour to build, and it costs next to nothing in supplies!

[Darcy] is using an old 9V power wart that he had lying around, but you can probably use any DC power supply. He designed the frame in SketchUp and cut it out with his CNC router, although a saw will work just as well for MDF. A piece of 40 gauge nickel chromium wire was strung taught between two 1/4-20 bolts, with one held back by a spring. The spring acts as a safeguard to prevent snapping the wire during overly aggressive cuts. This may be a simple build, but it does produce a handy tool.

[Darcy] demonstrates cutting foam with his creation in a video after the break. We think he could cut thin plastic with it as well—modify your 3D prints, anyone?—though he may need to crank up the voltage a bit.

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DIY Scroll Saw

January 19, 2014 by James Hobson 14 Comments

Scroll saws are super handy tools, but it’s sometimes hard to justify buying one for a single project. So why not make it your project? [SDX42] shows us how, using a…wait a second, is that an old sewing machine?

First a little back story. He picked up an old sewing machine that had been thrown out by its previous owner: they said it didn’t work right. He took it anyway and decided to fix it up. He encountered two problems. First, it turned out to be a lot harder to fix than he first imagined. Second, he realized he had no use for a sewing machine. What he did need, however, was a scroll saw.

A sewing machine is actually fairly similar to a scroll saw. They both work by converting rotary movement into linear reciprocation. The only difference is the layout. [SDX42] flipped the mechanism upside down and built a scroll saw frame on top of the stripped-down sewing machine. It’s a bit more complicated than that, but we’ll let him explain it to you in the video after the break.

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Refurbishing A Vibratory Tumbler With A Dryer Motor

January 14, 2014 by James Hobson 8 Comments

vibe

[Jake von Slatt] of the Steampunk Workshop is at again, this time refurbishing a cheap vibratory tumbler that had died after just one project.

The original Eastwood tumbler looked nice, but obviously didn’t go through much life-cycle testing at the company that designed it. Upon taking it apart, [Jake] discovered that the bearings in the motor were shot — after only a few hours of operation! Because of this he decided to start from scratch, keeping only the bowl, lid, and of course, the tumbling media.

[Jake’s] redesign makes use of Volkswagen brake drums for a very heavy duty base, a custom machined ball bearing plate made out of scrap aluminum, a flexible motor coupling made by welding a heavy spring onto two shafts, some more springs to balance the bowl, and a reclaimed dryer motor. It might not look pretty, but we think it’ll last a wee bit longer than the original.

He’s calling it his latest feat of post-apocalyptic engineering by using only parts on hand, and while we’d have to agree that his use of scrap material is impressive, we’d like to see him be able to power his rebuilt Bridgeport Mill off the grid when the apocalypse hits!

As always, he’s made an excellent video describing the project — don’t forget to check it out after the break.

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Bicycle Powered Sander

January 12, 2014 by James Hobson 23 Comments

sanding

[Andy] does a lot of framing and needed a way to sand down pieces at proper angles. He goes by the moniker [Organikmechanic] on YouTube, and as such is trying to rely less and less on electricity — so he’s created this hand-powered sander using components from a bicycle.

His first iteration just used the spindle off of a bicycle wheel as the main axle, but he quickly found it wasn’t rigid enough for the sanding disk. Instead he decided to make use of the entire crankshaft assembly off of an old bicycle. He cut the frame down to size, removed one of the pedals, and shortened the other one to a more useful hand cranking length. The main gear of the bicycle provides a large and sturdy mounting surface for his home-made sanding disk which consists of a large piece of rounded chipboard.

It’s a pretty clever use of recycled parts — but what do you think? Are you environmentally inclined enough to give up your power tools? A full video explanation of the project is after the break.

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A Simple (and Dirty) Bill Of Materials And Stock Management Utility

January 9, 2014 by Mathieu Stephan 36 Comments

As many readers may already know, when I’m not featuring your projects or working on the mooltipass I try to make simple things that may be useful to electronics enthusiasts. My latest creation is a simple bill of materials generation tool, which can also do simple stock management. Unfortunately for Linux users, this utility is made using Visual Basic functions in an Excel file.

It works fairly simply: just enter your schematics’ components references in the excel sheet, along with the corresponding Digikey webpage address. Click on the “fetch” button and the script will automatically get all your component characteristics from the internet and tell you the component costs depending on the number of prototypes you want to make. Then click the “sort BoM” button and your BoM will automatically be sorted by component type and value. Another functionality allows you to check that all the components present in your BoM are also present on the (very simple) Kicad generated one. Finally, using another Excel sheet containing your current stock, the Bill of Materials will let you know if you have enough components for the assembly stage. A video of the tool in action is embedded after the break, and you can download the BoM template here (.XLSM file) and the corresponding stock file there (.XLSM file).

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Mooshimeter: The ‘Why Didn’t I Think Of That’ Multimeter

January 8, 2014 by Brian Benchoff 110 Comments

Despite how useful multimeters are, there are a lot of limitations you just don’t think about because they’re the way electronic measurement has always been done. Want to measure voltage and current simultaneously? Better get two meters. Measuring something in a dangerous, inaccessible, or mobile place? You could rig up a camera system to show the meter’s display on a monitor, you know.

Mooshimeter is the better way of doing things. It’s a multichannel multimeter that communicates with your cell phone over a Bluetooth connection. With two channels. the Mooshimeter makes it easy to graph voltage against current to plot a beautiful IV curve on your smart phone. Being a wireless multimeter means you can stick the Mooshi inside a robot and get instantaneous feedback of how hard you’re driving your motors.

Far from being a two-trick pony, the Mooshimeter is actually a pretty good multimeter by itself. It can handle 600V and 10A with 24 bits of resolution. Here are the complete specs. The Mooshimeter is available for preorder here for $100 USD.

A FPGA Controlled Reflow Oven

December 28, 2013 by Eric Evenchick 33 Comments

For Christmas, [Hamster]’s wife gave him a mini-oven. Later that day, he tore it apart and built this FPGA controlled reflow oven.

We’ve seen plenty of reflow oven builds in the past. Most of those projects use a microcontroller to do closed loop control, sensing the temperature and toggling the heating element to hit a set point. This build uses the Papilo One FPGA development board as a controller. It implements a state machine that meets the reflow profile of the solder paste, ensuring SMD components are soldered properly.

The oven uses a MAX31855 to read temperature from a thermocouple. This device provides amplification, cold junction compensation, and analog to digital conversion which spits out the temperature over SPI. To control the heater, a 40A solid state relay is used.

The VHDL code that drives this oven is linked in the writeup, and has some interesting bits for those looking to experiment with FPGAs. It includes an SPI interface, display driver, and the temperature state machine logic.