Ask Hackaday: Help Me Pick A CAD Package

January 11, 2019 by Jenny List 143 Comments

Of all the skills that I have picked up over the years as an engineer, there is one that has stayed with me and been a constant over the last three decades. It has helped me work on electronic projects, on furniture, on car parts, robots, and even garments, and it is likely that I will continue using it periodically for the rest of my career. You see, I am a trained PAD expert.

Don't build this, it's fundamentally flawed! Sometimes the front of an envelope is as effective as its back. — Don’t build this, it’s fundamentally flawed! Sometimes the front of an envelope is as effective as its back.

PAD, you ask? OK, it’s an acronym of my own coinage, it stands for Pencil Aided Design, and it refers to the first-year undergraduate course I sat many years ago in which I learned technical drawing to the old British standard BS308. If I’m making something then by far the quickest way for me to visualise its design is to draw it, first a freehand sketch to get a feel of how everything will sit, then a series of isometric component drawings on graph paper with careful attention to dimensions and angles. Well, maybe I lied a little there, the graph paper only comes in when I’m doing something very fancy; the back of an envelope is fine as long as the dimensions on the diagram are correct.

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Make Your Own Dowels At Home

January 8, 2019 by Lewin Day 28 Comments

Dowels are a useful woodworking technology making it easy to connect several pieces of timber, particularly with the aid of adhesive. However, depending on where you live, it can be difficult to come by a wide variety of stock. This is particularly important if you’re concerned about appearances – cheap pine dowels could spoil the look of a delicately finished hardwood piece, for example.

Thankfully, it’s easy to make your own dowels at home. [Pask Makes] has used a simple dowel plate before, but this time, decided to build the deluxe version. A thick steel plate is drilled with a series of holes, and then mounted to a wooden block. Square stock can then be forced through the holes to produce the dowels.

[Pask] notes that there are several methods to use the dowel plate. Hammering the wood stock through the holes works best for hardwoods, while fitting the square stock into the chuck of a power drill and forcing it through while spinning gives a better finish on softer woods. There are also useful tips on how best to produce dowels, with notes on strength and grain orientation.

It’s a useful tool to have in your workshop, and means you can turn just about any wood into dowels for your woodworking projects. If you’re fresh to the world of wood, worry not – we’ve got the primer to get you started. Video after the break.

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Vintage Programmer Gets Modern Chip Adapter

January 8, 2019 by Tom Nardi 8 Comments

While trying to revive a Donkey Kong Jr arcade board, [Jelmer Bruijn] found himself in the market for an EPROM programmer and became the proud owner of a 1990’s era Dataman S4. Despite its age, it’s a fairly nice tool which allows you to read and write a laundry list of different EPROM types, all without being tied to a computer. The only catch is that a few types of chips need an adapter to work in the Dataman S4, some of which are unsurprisingly no longer available.

After some above and beyond support from the current crew at Dataman set him on the right track, [Jelmer] decided to try his hand at reverse engineering how the old adapters worked so he could build his own. His ultimate goal was to read 40 pin EPROMs on the 32 pin Dataman S4, but in the end he says the information he gathered should be applicable for building other adapters if you ever find yourself in need of such things.

As you might expect, there’s a bit more to the project than a simple pin adapter. [Jelmer] assumed some kind of shift register or latching arrangement would be required to make up for the shortage of pins on the Dataman S4’s ZIF socket. It was just a matter of figuring out how it all went together.

Luckily, [Jelmer] found that the programmer would happily attempt to perform operations on a 16 bit EPROM even though no adapter was physically present. This gave him a chance to probe around with a logic analyzer to figure out what it was trying to accomplish. The trick turned out to be splitting the 16 bit bus into two 8 bit buses which are requested sequentially.

With careful observation, close studying of 16 bit chip datasheets, and much brow furrowing, he was eventually able to come up a design that used five 74xx573 latches and put a schematic together in Eagle. There were a few kinks to iron out when the boards finally arrived, but ultimately the design worked on the first try. [Jelmer] says the same technique should work for 42 pin EPROMs, but as Dataman still actually sell adapters for those he decided not to supply schematics for it.

[Jelmer] tells us that he was inspired to send this success story our way after reading how our very own [Elliot Williams] took the long away around to erase a couple UV EPROMs recently While this isn’t the first time we’ve seen somebody have to hack support for 16 bit EPROMs into their programmer, it’s good to see that the manufacturer at least had the customer’s back in this case.

Making An Ultrasonic Cutter For Post-processing Tiny 3D Prints

January 7, 2019 by Donald Papp 58 Comments

An ultrasonic knife is a blade that vibrates a tiny amount at a high frequency, giving the knife edge minor superpowers. It gets used much like any other blade, but it becomes far easier to cut through troublesome materials like rubber or hard plastics. I was always curious about them, and recently made my own by modifying another tool. It turns out that an ultrasonic scaling tool intended for dental use can fairly easily be turned into a nimble little ultrasonic cutter for fine detail work.

Cheap ultrasonic scaler. The blue disk is for adjusting power. Foot switch not shown.

I originally started thinking about an ultrasonic knife to make removing supports from SLA 3D prints easier. SLA resin prints are made from a smooth, hard plastic and can sometimes require a veritable forest of supports. These supports are normally removed with flush cutters, or torn off if one doesn’t care about appearances, but sometimes the density of supports makes this process awkward, especially on small objects.

I imagined that an ultrasonic blade would make short work of these pesky supports, and for the most part, I was right! It won’t effortlessly cut through a forest of support bases like a hot knife through butter, but it certainly makes it easier to remove tricky supports from the model itself. Specifically, it excels at slicing through fine areas while preserving delicate features. Continue reading “Making An Ultrasonic Cutter For Post-processing Tiny 3D Prints” →

Modular Feeders For SMD Component Tape

January 6, 2019 by Lewin Day 12 Comments

Making one of something is pretty easy, and making ten ain’t too bad. But what if you find yourself trying to make a couple of hundred of something on your home workbench? Suddenly, small timesavers start to pay dividends. For just such a situation, you may find these modular SMD tape feeders remarkably useful.

The tape feeders come in a variety of widths, to suit different size tapes. You’ve probably seen if you’ve ever ordered SMD components in quantity from Mouser, Digikey, et al. SMD components typically ship on large tape reels, which are machine fed into automated pick and place machines. However, if you’re doing it yourself in smaller quantities, having these manual tape feeders on your desk can be a huge help. Rather than having scraps of tapes scattered across the working surface, you can instead have them neatly managed at the edge of your bench, providing components as required.

The feeders are modular, so you can stack up as many as you need for a given job. Rails are provided to affix them to the relevant work surface. We’ve seen similar work before – like this 3D-printed bowl feeder for SMD parts.

Return Of The Logic Probe

January 4, 2019 by Al Williams 10 Comments

We live in a day when it is very inexpensive to buy an oscilloscope, especially one with modest performance that hooks to a laptop. However, there was a time when even a surplus scope was out of reach for many people who liked to build things. A common alternative was the logic probe. At the low end, this could be an inverter and an LED, although it was more common to have a little extra circuitry to actually do a comparison to a reference voltage and present some indication of fast pulses — you might not be able to tell the frequency of a clock, but you could tell it wasn’t stuck. Of course, today with a microcontroller you can make a very sophisticated probe with less circuitry than a classic probe. We’ve seen a few takes on this and the latest is the DigiLogicProbe from [TheRadMan].

The probe is just a ATtiny85 board with a handful of components. A resistor and diode help protect the probe and the circuit under test. There are also a few LEDs and a buzzer. The rest of the project is software.

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The Solderdoodle Open Source Iron Rides Again

January 3, 2019 by Tom Nardi 25 Comments

Over the last year or so, cordless portable soldering irons have become all the rage. In fact, at this point a good number of Hackaday readers out there have likely traded in their full-size AC irons for a DC iron that’s only slightly larger than a pen. But before the big boom in portable irons, in the ye olden days of 2014, we brought you word of the open source Solderdoodle created by [Isaac Porras]. Based upon the Weller BP645 and featuring a 3D printed case, the DIY iron was designed to be charged from a standard USB port.

Now, [Isaac] is back with an updated version he calls the Solderdoodle Plus. It’s still based on the heating element from the Weller BP645, but now boasts twice the power, an improved 3D printed case, an intuitive touch-based user interface, and even some LED blinkenlights for good measure. As with the original Solderdoodle the hardware and software for the device are open source and you’re invited to build your own, though kits are also available through an already fully-funded Kickstarter campaign.

[Isaac] says that the temperature control functions on traditional corded soldering irons waste energy due to the large thermal mass they have to bring up to temperature. But with less thermal mass and a system of variable duty cycle pulsed power, he says the Solderdoodle Plus can do the same work as an old-school 60 watt iron while only consuming 10 watts. This allows the iron to maintain a constant 500°C for over an hour on the dual internal Panasonic NCR18500A lithium-ion batteries, and means you can charge it up with nothing more exotic than a micro USB cable.

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