Tool Hacks

2919 Articles

Turning A Bad Bench Supply Into A Better Bench Supply

December 1, 2019 by 24 Comments

‘Tis the season for dropping hints on what new doodads would make a hacker happy, and we have to admit to doing a little virtual window shopping ourselves. And as a decent bench power supply is on our list, it was no surprise to see videos reviews that the hive mind thinks will help us make a choice pop up in our feed. It’s a magical time to be alive.

What did surprise us was this video on a mashup of two power supplies, both of which we’ve been eyeing, with the result being one nicely hacked programmable bench PSU. It comes to us courtesy of [jeffescortlx], who suffered with one of those no-name, low-end 30V-5A bench supplies that has significant lag when changing the settings, to the point that it’s difficult to use, not to mention dangerous for sensitive components.

So he got a hold of a Riden RD6006 programmable buck converter, which is something like those ubiquitous DPS power supply modules we’ve seen so much of, only on steroids. The Riden takes up to 70V input and turns it into a 0-60V output at up to 6 amps, at constant current or constant voltage. It also just happens to (almost) fit as a replacement for the faceplate of the dodgy old supply. A few SMD resistors simulate the original front panel pots being pegged so that the supply outputs maximum voltage and current, and a little finagling with the case and fan was needed to fit everything up, but the finished product actually looks really good, and fixes all the problems of the original.

We love this hack, and may well cobble this together for our bench.

Continue reading “Turning A Bad Bench Supply Into A Better Bench Supply” →

DSP Spreadsheet: Talking To Yourself Using IQ

November 29, 2019 by 12 Comments

We’ve done quite a bit with Google Sheets and signal processing: we’ve generated signals, created filters, and computed quadrature signals. We can pull all that together into an educational model for two SDRs talking to each other, but it’s going to require two parts: modulation and demodulation. Guess what? We can do that with a spreadsheet.

The first step is to generate a reference clock for the carrier. You’ll need a cosine wave (I) and sine wave (Q). Of course, you also need the time base. That’s columns A-C in the spreadsheet and works like other signal generation we’ve seen.

Continue reading “DSP Spreadsheet: Talking To Yourself Using IQ” →

Steel Tubes And Ground Plates Form The Skeleton Of This DIY Vertical CNC Mill

November 27, 2019 by 29 Comments

If you’re going to do it yourself, you might as well outdo yourself. That seems to be the thinking behind this scratch-built CNC mill, and it’s only just getting started.

According to [Kris Temmerman], the build will cost about $10,000 by the time he’s done. So it’s not cheap, and a personal CNC from Tormach can be had for less, but that’s missing the point entirely. [Kris] built most of the structural elements for the vertical mill from cheap, readily available steel tubing, of the kind used for support columns in commercial buildings. Mounted to those are thick, precision-ground steel plates, which eat up a fair fraction of the budget. Those in turn hold 35 mm linear bearings and ball screws for the three axes, each powered by a beefy servo. The spindle is a BT30 with a power drawbar, belt-driven by an external motor that [Kris] doesn’t share the specs on, but judging from the way it flings chips during the test cut in the video below, we’d say it’s pretty powerful.

There’s still plenty to do, not least of which is stiffening the column; perhaps filling it with epoxy granite would do the trick? But it sure looks like [Kris] is building a winner here, and if he keeps the level of craftsmanship up going forward, he’ll have a top-quality machine on his hands.

Continue reading “Steel Tubes And Ground Plates Form The Skeleton Of This DIY Vertical CNC Mill” →

A Super Easy Laser Engraver

November 26, 2019 by 8 Comments

CNC comes in all shapes and sizes, from huge industrial lathes to homebuilt wire benders. [MJKZZ] has built their own compact rig, using optical drive parts to create a cute but effective laser engraver. (Video embedded below.)

The build aims to keep things simple by holding the laser stationary, and moving the bed instead. The laser in question is a 500 mW unit, driven by the Z axis on the Arduino CNC shield used to run the system. A DVD drive is taken apart, and the worm drive stepper motor assembly is used to slew the carriage back and forth, atop which is glued a bed. Upon this bed, a copy of the same assembly is then installed, offset 90 degrees, giving the X and Y axes.

The result of this setup is a lightweight moveable bed, controllable through Gcode with GRBL. With the laser situated above on some camera mounting gear, paper can be installed on the bed and engraved with ease. The resulting accuracy is admirable, and at full power, the laser is capable of cutting through the paper.

While it’s a lightweight rig, it could serve a purpose as a cheap and easy way to produce stencils from computerized artwork. Optical drives remain popular in the DIY CNC scene, as they’re a great way to source a moveable platform with all the mechanical considerations already worked out.

Continue reading “A Super Easy Laser Engraver” →

Casting Gears At Home

November 21, 2019 by 45 Comments

Automatic doors and gates are great, except when they fail, which seems to be about every three days in our experience. [MAD WHEEL] had just such a failure, with a plastic gear being the culprit. Rather than buy a new drive unit, they set about casting a replacement in metal.

The video is light on instructions and heavy on progressive rock, and may be a little difficult to follow for beginners. The process begins by gluing the original plastic part back together, and filling in the gaps with epoxy putty. A mould is then created by setting the gear in a gelatine/glycerine mixture. This mould is then filled with wax to create a wax copy of the original part. The wax gear is fitted with cylindrical stems to act as runners for molten metal, and then a plaster mould is made around the wax positive. Two plaster moulds are made, which are placed in an oven to melt out the wax.

The aim was to cast a replacement part in aluminium. The first attempt failed, with the aluminium cooling too rapidly. This meant fine details like the gear teeth simply didn’t cast properly, creating a useless metal blob. On the second attempt, the plaster mould was heated first, and this kept things hot enough to allow the aluminium to fill in the finer details. With that done, it was a simple matter of some post-processing to remove the runners, clean up the gear teeth and refine the shape of the gear on the lathe.

The resulting part does its job well, meshing properly with the other gears in the drivetrain and moving the gate effectively. Many in the comments have stated that the original gear being plastic was likely as a safety measure, to strip out in the event the gate is jammed. While this may be true, it’s a far more robust design practice to instead use a breakable plastic key rather than breaking an entire gear in the event of a problem.

Casting is quite accessible to the dedicated home maker. It’s a great way to make custom metal parts once you’ve learned the fundamentals! Video after the break.

Continue reading “Casting Gears At Home” →

KiCad Action Plugins

November 19, 2019 by 47 Comments

The last two years has been a particularly exciting time for KiCad, for users, casual contributors, and for the core developers too. Even so, there are many cool new features that are still in process. One bottleneck with open-source development of complex tools like KiCad is the limited amount of time that developers can devote for the project. Action plugins stand to both reduce developer load and increase the pace of development by making it easier to add your own functionality to the already extensible tool.

Sometime around version 4.0.7 (correct us if we’re wrong), it was decided to introduce “action plugins” for KiCad, with the intention that the larger community of contributors can add features that were not on the immediate road map or the core developers were not working on. The plugin system is a framework for extending the capabilities of KiCad using shared libraries. If you’re interested in creating action plugins, check out documentation at KiCad Plugin System and Python Plugin Development for Pcbnew. Then head over to this forum post for a roundup of Tutorials on python scripting in pcbnew, and figure out how to Register a python plugin inside pcbnew Tools menu. Continue reading “KiCad Action Plugins” →

Used EDM Electrodes Repurposed As Air Bearings For Precision Machine Tools

November 18, 2019 by 14 Comments

If you’ve ever played air hockey, you know how the tiny jets of air shooting up from the pinholes in the playing surface reduce friction with the puck. But what if you turned that upside down? What if the puck had holes that shot the air downward? We’re not sure how the gameplay would be on such an inverse air hockey table, but [Dave Preiss] has made DIY air bearings from such a setup, and they’re pretty impressive.

Air bearings are often found in ultra-precision machine tools where nanometer-scale positioning is needed. Such gear is often breathtakingly expensive, but [Dave]’s version of the bearings used in these machines are surprisingly cheap. The working surfaces are made from slugs of porous graphite, originally used as electrodes for electrical discharge machining (EDM). The material is easily flattened with abrasives against a reference granite plate, after which it’s pressed into a 3D-printed plastic plenum. The plenum accepts a fitting for compressed air, which wends its way out the micron-sized pores in the graphite and supports the load on a thin cushion of air. In addition to puck-style planar bearings, [Dave] tried his hand at a rotary bearing, arguably more useful to precision machine tool builds. That proved to be a bit more challenging, but the video below shows that he was able to get it working pretty well.

We really enjoyed learning about air bearings from [Dave]’s experiments, and we look forward to seeing them put to use. Perhaps it will be in something like the micron-precision lathe we featured recently.

Continue reading “Used EDM Electrodes Repurposed As Air Bearings For Precision Machine Tools” →