Handheld Multimeter Converted For Bench Top Use

May 31, 2021 by Chris Lott 14 Comments

A few years ago [Mechatrommer] got one of the low-cost Aneng Q1 multimeters and has converted it into a bench top meter. He first tried and failed to do an LCD modification and set it aside. It remained in a storage box until he needed another meter to repair his rubidium frequency standard. Finding that off-the-shelf bench multimeters were literally off-the-shelf — they were too deep for his bench — he decided to take matters into his own hands.

He dug out the dismantled an Aneng Q1 and undertook a more drastic modification than before, slicing the multimeter into three pieces and mounting each piece in a new enclosure. The power-draining back-lit display of the Q1, problematic in a battery-powered handheld meter, isn’t an issue in a bench top design. [Mechatrommer] replaced the battery pack with a mains powered supply. Next he reconnected all the signals which had been interrupted by the bandsaw, and now the meter lives again.

The resulting meter is pleasing enough (ignore the sideways input jacks) and looks like a typical piece of home-brew test gear. The enclosure has a lot of empty space, which he uses to stow test leads and sandwiches (we saw a similar storage compartment in [Dave Jones]’s recent teardown of a portable Fluke 37 multimeter). Kudos to [Mechatrommer] for coming up with this unusual conversion project.

We’ve written about the differences between these low-cost and more professional multimeters before if you want to learn more.

Thanks to [Adrian] for the tip.

A Chainsaw Gives This Winch Some Grunt

May 31, 2021 by Jenny List 11 Comments

For a satisfying Youtube watching session there is noting like some quality machine shop work, and that’s exactly what [Made In Poland] supply with their conversion of a small 12V winch to power from a chainsaw. The finished product contains not much more than the gearbox and shaft components from the original, but the mesmerising sight of rusty steel stock being transformed into dimension-perfect components which come together to form an entirely new assembly is as always a draw.

The conversion starts with the removal and disassembly of the motor to reveal its shaft and the locking mechanism for the drum. The shaft is then turned down and a collar manufactured to couple it to the drive spline on a chainsaw. We’re pleased to see that the chainsaw isn’t modified in this build, instead the blade is simply unscrewed and the winch attached in a reversible process. Finally, the original drum is deemed too small for the application, so a new drum is fabricated. We see the result on a Polish farm, happily participating in some forestry work and even pulling their pickup truck when it became stuck.

This is by no means the first time we’ve featured [Mad in Poland] in these pages, not least with this electromagnetic circle cutting jig.

Continue reading “A Chainsaw Gives This Winch Some Grunt” →

Chainsaw Cuts More Than Timber

May 29, 2021 by Bryan Cockfield 13 Comments

We often take electricity for granted, to the point of walking into a room during a power outage and still habitually flipping the light switch. On the other hand, there are plenty of places where electricity isn’t a given, either due to poor infrastructure or an otherwise remote location. To get common electric power tools to work in areas like these requires some ingenuity like that seen in this build which converts a chainsaw to a gas-driven grinder that can be used for cutting steel or concrete. (Video, embedded below.)

All of the parts needed for the conversion were built in the machine shop of [Workshop from scratch]. A non-cutting chain was fitted to it first to drive the cutting wheel rather than cut directly, so a new bar had to be fabricated. After that, the build shows the methods for attaching bearings and securing the entire assembly back to the gas-powered motor. Of course there is also a custom shield for the grinding wheel and also a protective housing for the chain to somewhat limit the danger of operating a device like this.

Even though some consideration was paid to safety in this build, we would like to reiterate that all the required safety gear should be worn. That being said, it’s not the first time we’ve seen a chainsaw modified to be more useful than its default timber-cutting configuration, like this build which turns a chainsaw into a metal cutting chop saw.

Continue reading “Chainsaw Cuts More Than Timber” →

JTAG Hat Turns Raspberry Pi Into A Networked Debugger

May 28, 2021 by Tom Nardi 7 Comments

Over the last year or so we’ve noticed a definite uptick in the number of folks using OpenOCD on the Raspberry Pi. It’s a cheap and convenient solution for poking around with various microcontrollers and embedded devices, but not always the most elegant. Looking to improve on the situation somewhat, [Matthew Mets] has been working on a purpose-built JTAG Hat to clean things up a bit.

Onboard level shifters allow you connect to JTAG and SWD interfaces from 1.8 to 5 V, and if you power the target device from the Pi itself, there’s even support for measuring the voltage and current. To connect up to your target, the open hardware board features a “legacy” pin header perfect for jumper wires, as well as a dedicated 10-pin Cortex Debug Connector. Whether you spin up your own or buy one assembled, it certainly looks like a tool worth having around if you often find yourself working with the appropriate chips.

In addition to the design files for the hardware, [Matthew] has also provided some nice documentation on how to get the software side of things up and running. Starting with a blank SD card, it walks you through the initial setup of the Raspberry Pi all the way through the installation and configuration of a patched version of OpenOCD designed to support the JTAG Hat.

If you spend more time working with 8-bit AVR chips, don’t worry. Last year we covered a similar project to turn everyone’s favorite Linux SBC into an all-in-one microcontroller development powerhouse.

Yet Another Rigol DS1054Z Viewer

May 26, 2021 by Chris Lott 22 Comments

Tired of squinting at the small numbers on the oscilloscope display, [Alfred] aka [Gaze@] decided to take matters into his own hands and wrote yet another tool to remotely view images from a Rigol DS1054Z. At least that was the initial idea. But, it grew unexpectedly — as [Alfred] says, “the more the project turned out to be fun, the more it got out of hand”. We know the feeling well.

In addition to being able to simply view and export the screen, the program implements waveform measurements (we’re not sure if it is using the measurement ability of the ‘scope, or actually performing measurements in the program). And as you can see in the animated GIF of the program in operation over on the GitHub repository, the numbers are certainly clear and legible. His problem of squinting at the small screen has indeed been solved.

This is coded in Pascal (FPC Lazarus), but we weren’t able to browse the program because [Alfred] hasn’t posted the source code yet. It is written only for Linux, and he has tested it on Ubuntu, Debian, Fedora, and Manjaro. The project relies on Python, PyVisa, and gtk2, and talks to your DS1054Z over USB or LAN. The installation instructions are well documented, but as [Alfred] himself warns, if you encounter trouble arising from subtle dependency version conflicts, you may need to be a nerd and/or a pensioner with unlimited time on your hands to solve them. There is no users guide nor extensive help according to [Alfred]. However, simple hints might be found in hover text or by pressing F1. Disclaimers aside, this looks like an interesting project to try out.

As [Alfred] notes, there are many other tools available to fetch data and images from your Rigol oscilloscope. [Jenny List] wrote a two-part series on using Python to control your test instruments, and here’s an example of a simple Python script that does a screen grab. Do you have a favorite way to remotely operate your oscilloscope? Let us know in the comments below.

Getting Started With Aluminum Extrusions

May 25, 2021 by Al Williams 64 Comments

T-slot extrusions used to be somewhat mysterious, but today they are quite common thanks to their use in many 3D printers. However, it is one thing to assemble a kit with some extrusions and another thing to design your own creations with the material. If you ever had a Play-Doh Fun Factory as a kid, then you know about extrusions. You push some material out through a die to make a shape. Of course, aluminum extrusions aren’t made from modeling clay, but usually 6105-T5 aluminum. Oddly, there doesn’t seem to be an official standard, but it is so common that there’s usually not much variation between different vendors.

We use extrusions to create frames for 3D printers, laser cutters, and CNC machines. But you can use it anywhere you need a sturdy and versatile frame. There seems to be a lot of people using them, for example, to build custom fixtures inside vans. If you need a custom workbench, a light fixture, or even a picture frame, you can build anything you like using extrusions. Continue reading “Getting Started With Aluminum Extrusions” →

Optical Sensor Keeps Eye On Wandering Saw Blade

May 24, 2021 by Tom Nardi 17 Comments

Over the last year or so, we’ve been checking in on the progress [Andrew Consroe] has been making with his incredible CNC scroll saw project. While we were already impressed with his first prototype version, he somehow manages to keep pushing the envelope forward with each new upgrade, and we’re always excited when one of his progress reports hits the inbox.

Recently he’s been struggling with the fact that the considerable flexing of the scroll saw’s ultra-thin blade introduces positional errors while cutting. To combat this, he’s developed an ingenious sensor that can track the movement of the blade in two dimensions without actually touching it. Utilizing the Raspberry Pi HQ camera, a 3D printed framework, and some precisely placed mirrors, [Andrew] says his optical sensor is able to determine the blade’s position to within 10 microns.

In the video below [Andrew] goes over how his “Split Vision Periscope” works, complete with some ray traced simulations of what the Pi camera actually sees when it looks through the device. After experimenting with different lighting setups, the final optical configuration presents the camera with two different perspectives of the saw blade set on a black background. That makes it relatively easy to pick out the blade using computer vision, and turn that into positional information.

The periscope arrangement is particularly advantageous here as it allows the camera and lens to be placed under the work surface and well away from the actual cutting, though we’re interested in seeing how it fares against the dust and debris that will inevitably be produced as the saw cuts. While he hit all of his design goals, [Andrew] does note that his mirrors do leave some room for improvement; but considering he hand cut them out of old hard drive platters we think the results are more than acceptable.

An incredible amount of progress has been made since the first time we saw the CNC scroll saw, and we’re eager to see this new sensor fully integrated into the next version of [Andrew]’s impressive long-term project.

Continue reading “Optical Sensor Keeps Eye On Wandering Saw Blade” →