Sorting Resistors With 3D Printing And A PIC

December 30, 2016 by Al Williams 20 Comments

If you aren’t old enough to remember programming FORTRAN on punched cards, you might be surprised that while a standard card had 80 characters, FORTRAN programs only used 72 characters per card. The reason for this was simple: keypunches could automatically put a sequence number in the last 8 characters. Why do you care? If you drop your box of cards walking across the quad, you can use a machine to sort on those last 8 characters and put the deck back in the right order.

These days, that’s not a real problem. However, we have spilled one of those little parts boxes — you know the ones with the little trays. We aren’t likely to separate out the resistors again. Instead, we’ll just treasure hunt for the value we want when we need one.

[Brian Gross], [Nathan Lambert], and [Alex Parkhurst] are a bit more industrious. For their final project in [Bruce Land’s] class at Cornell, they built a 3D-printed resistor sorting machine. A PIC processor feeds a resistor from a hopper, measures it, and places it in the correct bin, based on its value. Who doesn’t want that? You can see a video demonstration, below.

Continue reading “Sorting Resistors With 3D Printing And A PIC” →

Review: Digilent Analog Discovery 2

December 28, 2016 by Al Williams 57 Comments

I recently opened the mailbox to find a little device about the size of White Castle burger. It was an “Analog Discovery 2” from Digilent. It is hard to categorize exactly what it is. On the face of it, it is a USB scope and logic analyzer. But it is also a waveform generator, a DC power supply, a pattern generator, and a network analyzer.

I’ve looked at devices like this before. Some are better than others, but usually all the pieces don’t work well at the same time. That is, you can use the scope or you can use the signal generator. The ones based on microcontrollers often get worse as you add channels even. The Analog Discovery 2 is built around an FPGA which, if done right, should get around many of the problems associated with other small instrumentation devices.

I’d read good things about the Discovery 2, so I was anxious to put it through its paces. I will say it is an impressive piece of gear. There are a few things that I was less happy with, though, and I’ll try to give you a fair read on what I found both good and bad.

Continue reading “Review: Digilent Analog Discovery 2” →

In Defense Of The Electric Chainsaw

December 28, 2016 by Jenny List 94 Comments

Here at Hackaday we are a diverse bunch, we all bring our own experience to the task of bringing you the best of the hardware scene. Our differing backgrounds were recently highlighted by a piece from my colleague [Dan] in which he covered the teardown of a cordless electric chainsaw.

It was his line “Now, we’d normally shy away from any electric chainsaw, especially a cordless saw, and doubly so a Harbor Freight special“. that caught my eye. I’m with him on cordless tools which I see as a cynical ploy from manufacturers to ensure 5-yearly replacements, and I agree that cheap tools are a false economy. But electric chainsaws? Here on this small farm, they’re the saw of choice and here’s why.

Continue reading “In Defense Of The Electric Chainsaw” →

Open-Source Parametric CAD In Your Browser

December 24, 2016 by Cameron Coward 46 Comments

Until recently, computer-aided design (CAD) software was really only used by engineering companies who could afford to pay thousands of dollars a year per license. The available software, while very powerful, had a very high learning curve and took a lot of training and experience to master. But, with the rise of hobbyist 3D printing, a number of much more simple CAD programs became available.

While these programs certainly helped makers get into 3D modeling, most had serious limitations. Only a few have been truly open-source, and even fewer have been both open-source and parametric. Parametric CAD allows you to create 3D models based on a series of parameters, such as defining a cube by its origin and dimensions. This is in contrast to sculpting style 3D modeling software, which is controlled much more visually. The benefit of parametric modeling is that parameters can be changed later, and the model can be updated on the fly. Features can also be defined mathematically, so that they change in relation to each other.

While still in its infancy, JS.Sketcher is seeking to fill that niche. It is 100% open-source, runs in your browser using only JavaScript, and is fully parametric (with both constraints and editable dimensions). At this time, available features are still pretty limited and simple. You can: extrude/cut, revolve, shell, and do boolean operations with solids. More advanced features aren’t available yet, but hopefully will be added in the future.

Continue reading “Open-Source Parametric CAD In Your Browser” →

Dead-Bug Logic Probe In A Magic Marker

December 24, 2016 by Dan Maloney 13 Comments

Logic probes are simple but handy tools that can be had for a couple of bucks. They may not be the sexiest pieces of test gear, nor the most versatile, but they have their place, and building your own logic probe is a great way to understand the tool’s strength and weaknesses.

[Jxnblk]’s take on the logic probe is based on a circuit by [Tony van Roon]. The design hearkens back to a simpler time and is based on components that would have been easy to pick up at any Radio Shack once upon a time. The logic section is centered on the venerable 7400 quad 2-input NAND gate in the classic 14-pin DIP format. The gates light separate LEDs for high and low logic levels, and a 555 timer chip in a one-shot configuration acts as a pulse stretcher to catch transients. The DIP packages lend themselves to quick and dirty “dead bug” construction, and the whole thing fits nicely into a discarded marking pen.

It’s a simple build and a nice form factor for a useful tool, but for an even slimmer package like an old syringe you’ll probably have to go with SMD components. And when you graduate from the simple logic probe, you might want to check out the capabilities of this smart probe.

Jump Into Pogo

December 20, 2016 by Al Williams 19 Comments

A lot of modern PCBs have small pads with no components attached. They are often used as test points, JTAG ports, or programmer connections. There’s no connector on the board, just pads. To use those, test equipment and programmers utilize pogo pins. These are small pins with a spring inside, reminiscent of a tiny pogo stick.

To use pogo pins effectively, you need a way to hold them in the right position and something to put pressure on them while they are in use. [Joshua Brooks] used a strip board to hold them in place and clothes pin to keep the pressure on them.

Continue reading “Jump Into Pogo” →

Clear The Air Around Your CNC Router With A Custom Dust Shroud

December 18, 2016 by Dan Maloney 11 Comments

Using a CNC router is a dusty business if your material of choice is wood. Sure, you can keep things tidy by chasing the cutter around the table with a shop vac, but that sort of takes the fun out of having a machine that can make cuts without you. The big boy machines all have integrated dust collection, and now you can too with this 3D-printed CNC router dust shoe.

Designed specifically for the X-Carve with a DeWalt 611 router, [Mark Edstrom]’s brush is a simple design that’s almost entirely 3D printed. The shroud encloses the router body and clamps to the mounting bracket, totally surrounding the business end of the machine. The cup is trimmed with a flexible fringe to trap the dust and guide it to the port that fits a small (1-1/4″ diameter) shop vac hose. The hose is neatly routed along the wiring harness, and the suction is provided by a standard shop vac.

Files for the cup are up on Thingiverse; we suspect it’d be easy to modify the design to work with other routers and dust collectors. You might even find a way to shroud a laser cutter and capture the exhaust with a DIY filter.

Continue reading “Clear The Air Around Your CNC Router With A Custom Dust Shroud” →