CNCing An X-Acto Knife Holder

May 24, 2019 by Lewin Day 22 Comments

X-acto knives are popular as the scalpel of the craft world. Obviously, holders for the blades are available off-the-shelf, but you needn’t settle for store bought. [Ariel Yahni] set about making an X-acto handle of their own, and it shows just how quick and easy making your own tools can be.

The blades are first measured to determine the appropriate dimensions for the holder. With this done, the basic shape of the handle is drawn up in CAD software using simple primitive shapes and lines. Then it’s just a simple matter of jigging up a piece of aluminium stock in the CNC machine, and letting it do its thing.

The final result needs minimal finishing – primarily just an inspection of the parts, minor deburring and the drilling and tapping of the mount holes. With a couple of socket head cap screws and an X-acto blade installed, it’s ready for work.

We see a lot of interesting tool builds around these parts. You might consider making your own ultrasonic cutter if you’re regularly finishing 3D printed parts. Video after the break. Continue reading “CNCing An X-Acto Knife Holder” →

Better Simulators With Homemade Potentiometers

May 24, 2019 by Bryan Cockfield 22 Comments

Perhaps you’ve played a flight simulator before, using something like a mouse and keyboard. That’s a fine experience, but like any other activity you can get a lot more out of it if you put a little more effort into the experience. Some will upgrade to a joystick for a modest improvement, and others will build incredible accurate cockpit replicas down to the smallest detail. The builders of these “pits” are always looking for ways of improving their setups, and it’s from this world that we find a method of building specialized, inexpensive hall-effect sensors.

A hall-effect sensor is a circuit that outputs a voltage based on the presence of an external magnetic field. These can be used to make compasses, but with a permanent magnet in close proximity can also be used to create a potentiometer-like device at lower cost and with higher precision than a similarly-priced pot. There was a method of building these in the simulator world using the housing of a Bic pen and some strong glue, but [LocNar] has improved on this method as well. He repurposed some bearings and some stock metal tubing in order to fabricate a professional-level sensor at a fraction of the cost.

This build is essentially a solution for anyone needing a potentiometer that’s easier to build, less expensive, has higher precision, and interacts with a digital input in a much more predictable (and programmable) way. Certainly this has applications in the simulator world, but will work for many other applications. If you’ve never thought about the intricacies (and shortcomings) of potentiometers, some other folks have taken a deep dive into that as well.

Thanks to [Keith O] for the tip!

Set Your Nuts (and Bolts) Free With This Induction Heater

May 22, 2019 by Adam Fabio 36 Comments

[Amon] built an induction heater to break stuck bolts loose. If you work on cars, machines, or anything big and metal, sooner or later you’re going to run into stuck nuts and bolts. Getting them unstuck usually involves penetrating oil, heat from a torch, and cheater bars. Heat usually works well, as heating the bolt makes the metal expand, helping it to break free. Torches aren’t exactly precision instruments though, and things can get interesting using one in tight spaces.

Fire isn’t the only way to heat a bolt through. Electricity can do the job as well. But why use a heating coil when you can grab an induction heater. Mechanics have had induction heaters in their toolboxes now for a few years, under names such as Bolt Buster or Mini Ductor. These devices cost several hundred dollars. However, you can purchase a 1000 watt induction heater from the usual sources for around $30. These are open frame Zero Voltage Switching (ZVS) power supplies, with uninsulated copper coils.

[Amon] bought one of these induction heaters, along with a beefy 24V, 40 amp switch mode supply to power it. He built the two into a plastic enclosure. A relay energizes the induction heater, so it isn’t always running. The key to this build is the handle. Rather than mount the induction coil directly on the supply, [Amon] ran two extension wires to a 3d printed gun style handle. This keeps the bulky part of the heater away from the work. The copper tube coil was re-shaped to better work with the gun. Some fiberglass sleeve keeps everything insulated, even at extreme temperatures.

The result is a very useful heater, ready to bust loose some bolts. We’ve seen homebuilt ZVS supplies powering induction coils before. It will be interesting to see how well these commercial units hold up.

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Paperclip Breadboard

May 21, 2019 by Al Williams 28 Comments

TV’s MacGyver would love the breadboard arrangement we saw recently: it uses paperclips and crimping to make circuits that can be more or less permanent with no soldering. The basic idea is simple. A cardboard base has a piece of paper affixed. Metal paperclips are bent straight and glued to the paper using PVA glue (you know, like ordinary Elmer’s; hot glue would probably work, too). You could probably salvage wires out of old house wiring that would work for this, too.

The scheme uses two sizes of paper clips. Large ones are made straight and form the rails, while small paperclips make connections. The rails are bent to have a little “ear” that pushes into the cardboard base to hold them still. A little glue stabilizes them. The ears poke out the back, so the author suggests covering them with duct tape, hot glue, or another piece of cardboard. Using the top of a shoebox would also solve the problem.

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Design Tips For Easier CNC Milling

May 20, 2019 by Lewin Day 12 Comments

CNC machining is a wonderful thing, taking away a lot of the manual work required in machining and replacing it with accurate, repeatable computer control. However, this doesn’t mean that you can simply click a few buttons and become a great machinist overnight. There are a wide variety of skills involved in utilizing these tools effectively, and [Adam Bender] has created a guide to help budding makers learn the skills of design for CNC milling.

[Adam]’s guide starts from a basic level, considering 3-axis CNC milling with the most commonly used tools. From there, a whole range of tips, tricks, and potential pitfalls are discussed to help new machinists get to grips with CNC milling. Everything from dogbone corners, to tool selection and feature heights are covered, as well as cost-saving techniques like minimising the number of setups required.

These are skills any engineer will learn in a hurry when approaching an experienced CNC machinist, but it’s always better to go in forewarned and forearmed. Of course, for those eager to not just work with, but build their own CNC machine, we’ve covered that base too. Video after the break.

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A Cyclonic Vacuum Cleaner On A Hacker’s Budget

May 17, 2019 by Tom Nardi 19 Comments

Have you ever seen a product in the store and been shocked at what the manufacturer was trying to charge for it? Since you’re reading Hackaday, we can safely assume the answer to that question; building a homebrew version of some commercial product for a fraction of its retail price is practically a rite of passage around these parts. So it’s fitting that for his entry into the 2019 Hackaday Prize, [Madaeon] submitted the “DIYson”, an open source version of a popular high-end vacuum made by a British company who’s name you can surely guess.

As [Madaeon] explains on the project’s Hackaday.io page, the idea behind “cyclonic” vacuums is not particularly complex. Essentially, with a powerful enough blower and carefully designed chamber, the incoming air will spin around so fast that dust is pulled out by centrifugal force. The trick is getting it working on a small enough scale to be a handheld device. Especially given the energy requirements for the blower motor.

Luckily for the modern hacker, we’re living in the “Golden Age” of DIY. With a 3D printer you can produce plastic components with complex geometry, and thanks to a resurgence in remote controlled aircraft, powerful motors and high capacity lithium-ion batteries are easily obtainable. Powered by what’s essentially the hardware that would go into an electric ducted fan plane, the total cost of all the electronics for the DIYson comes in right around $60 USD. Even with a roll of printer filament added to the mix, you’re still comfortably at half the cost of the “name brand” alternative.

With some refinements, [Madaeon] hopes that this open source dust-buster will be a staple of labs and hackerspaces all over the world. Judging by the performance his early prototype shows in the video after the break, we know we wouldn’t mind having one.

Continue reading “A Cyclonic Vacuum Cleaner On A Hacker’s Budget” →

Air Compressor From Fridge Parts Gets An Upgrade

May 15, 2019 by Lewin Day 21 Comments

Air compressors are often loud, raucous machines – but they don’t have to be. [Eric Strebel] built a remarkably quiet compressor using parts salvaged from an old fridge. After several years of use, it was due for an upgrade (Youtube link, embedded below}.

While performance of the original setup was good, [Eric] desired a compressor with more capacity for his resin casting activities. A 15 gallon air tank was sourced from a damaged Craftsman brand compressor, and pressed into service. The build involved plenty of sheet metal work to mount the various components, as well as an upgrade to the pressure regulator.

During the refit, [Eric] takes the time to answer questions from the audience about his original build. He notes that the fridge compressor has worked well without using any noticeable amount of oil, and that there was a problem with water build up in the original tank which has been solved in the new rig.

It’s a great example of building your own tools, which can provide years of service if done right. Check out our write up on [Eric]’s first build, or his work on photogrammetry. Video after the break.

Continue reading “Air Compressor From Fridge Parts Gets An Upgrade” →