These days, the bar for home-built projects is high. With 3D printers, CNC, and cheap service providers, you can’t get away with building circuits in a shoe box or an old Tupperware container. While most people now have access to additive manufacturing gear, traditional subtractive equipment is still a bit less common. [Someone Should Make That] had thought about buying a “minimill” but he had read that they were not worth it. Like a lot of us, he decided to do it anyway. The pros and cons are in the video you can watch below.
During setup, he covered a few rumors he’d heard about these type of mills, including they are noisy, have poor tolerances, and can’t work steel. Some of these turned out to be true, and some were not.
If you’re big into the soldering iron scene, you’ve probably heard of the AxxSolder project. Now, it’s been updated with a whole host of nifty new features. It’s AxxSolder 3.0!
If you’re not intimately familiar with AxxSolder, it’s an open-source iron design based around the popular JBC soldering iron tips. Relying on the STM32G431CBT6 to run the show, it comes in two versions—a lightweight portable design, and a desktop version based around the JBC ADS soldering iron stand. So far, so familiar.
The new 3.0 version adds new functionality, however. Where the previous model ran off any old DC power source from 9 to 26 volts, the new version can run off a USB Power Delivery supply. Thus, you can grab any old USB-PD device, like a laptop charger, and run your iron off that.
The new version also uses a larger color TFT screen with some buttons added on as an improved user interface. Thermal performance is improved, and it’s additionally capable of measuring the current draw by the tip, so you can monitor the performance of the iron in great detail.
When using a manual machine tool such as a lathe or milling machine, there can be a lot of pressure to read the position and feed the axes at the correct rate. That’s why modern machines typically have some form of digital read-out (DRO). [Stefano Bertelli] has created a simple Raspberry Pi based DRO with an additional twist, that of a linked motor drive output.
Realtime encoder position reading and motor control are best done with a dedicated microcontroller, ideally with a proper RTOS.
The axes that need to be monitored should be mechanically attached to a position sensor like a linear encoder or a rotary type. Using a linear sensor with a linear axis instead of a rotary encoder on the downstream dial is better. For the readout unit, [Stefano] used a WaveShare 7-inch touchscreen module with a Raspberry Pi 3 for the UI of the readout unit. The Pi has a custom-designed HAT, that performs power conditioning and provides a robust RS485 interface. Connected via that RS485 link is another custom PCB based on an STM32F411 with a few supporting power supplies and interfacing components. The job of this board is to interface to the position encoders, reading positioning pulses using interrupts. There is an additional stepper motor drive courtesy of a ULN2003 Darlington driver to allow the control of a single motorised axis. An additional motor driver module is required, which should be no surprise since driving a milling machine axis will require a fairly beefy motor. This GitHub repo contains the FreeRTOS-based firmware for this board. This motor drive has the ability to be connected to a measuring axis in a programmable way, enabling one axis to be adjusted to follow or jump in controlled steps with another. This feature can significantly simplify certain types of machining operations, as [Stefano] elaborates in the video.
Lastly, the Raspberry Pi runs a simple Python application with Kivy for the GUI. As [Stefano] explains in the video below, this makes debugging and modification quite simple.
[Ted Fried] recently found a beautiful HP 1600A/1607A logic analyzer set. State of the art in 1975, it looks like glorious Space Age equipment today. He decided to hook it up some modern gear to put it through its paces.
Wanting to give the equipment a proper shakedown, he enlisted a Teensy 4.1 to spit a deluge of logic at the HP unit. The microcontroller was tasked with generating 32 data signals along with two clock outputs to give the analyzer plenty to analyze. The HP 1600A handled this no problem, so [Ted] kept tinkering.
His next feat was to explore the addressable “MAP” function of the unit, which allowed writing to the 64×64 pixel display. The Teensy 4.1 was easily able to send images to the display, but [Ted] isn’t stopping there. He’s got plans to do the usual thing and get Bad Apple going on the hardware.
Getting a logic analyzer to analyze logic isn’t much of a hack, sure. But it’s instructive of how to approach working with such hardware. If you want to spit a bunch of logic out fast, a Teensy 4.1 is a great choice because it’s got a ton of IO and a ton of clock cycles to tickle it with.
We enjoyed seeing this old piece of hardware light up the phosphors once more. If you’ve got your own projects going on with classic bits of HP test gear, don’t hesitate to let us know!
If you’re getting PCBs professionally made, silkscreen usually comes free as part of the package. However, if you’re making your own, the job is on you. [Tony Goacher] makes his own PCBs on a CNC router, so he’s not getting any silkscreening as part of that bargain. But he wondered—could he do something analogous with a laser cutter?
The answer is yes. The silkscreen layer was first exported from DesignSpark, with the file then sent to LightBurn to prep it for laser cutting. The board outline layer was first engraved on to a piece of scrap as an alignment aid. Then, the board was placed in the laser cutter, with the silkscreen scorched directly on to the fiberglass.
The results are encouraging, if imperfect. [Tony] says he ran at “quite fast speed at quite high power.” The markings are all there, but they’re a little melty and difficult to read. He noted at lower speeds and lower power, the results were a bit more readable.
These days, unit conversions aren’t something we have to worry about so much. If you’re sitting at a computer, you can usually just tap away in your browser to get a quick conversion done, or you can ask your smartphone for an answer. [HackMakeMod] wanted a bespoke device for this, though, and built a tiny little retro-styled unit converter.
It’s a straightforward build that uses a handful of familiar components. An ESP8266 D1 Mini development board is the heart of the operation, running off a small battery harvested from a disposable vape pen. It runs a 0.96 inch OLED display which has a menu system for selecting from a whole bunch of different unit conversions. Navigating the menu is done via a rotary encoder with an integrated push button. Everything’s wrapped up in a neat 3D printed enclosure that was given a nice worn, weathered finish after printing.
[HackMadeMod] also clearly thought about usability, too. Turning the encoder dial faster ramps up the numbers exponentially so you’re not stuck jogging for ages when you need to enter a bigger figure.
It’s not something a lot of us would have a use case for, given that smartphones are always there and probably faster to use. However, it is a tidy little gadget, and a well-presented one at that. Video after the break.
Imagine an electronics lab. If you grew up in the age of tubes, you might envision a room full of heavy large equipment. Even if you grew up in the latter part of the last century, your idea might be a fairly large workbench with giant boxes full of blinking lights. These days, you can do everything in one little box connected to a PC. Somehow, though, it doesn’t quite feel right. Besides, you might be using your computer for something else.
I’m fortunate in that I have a good-sized workspace in a separate building. My main bench has an oscilloscope, several power supplies, a function generator, a bench meter, and at least two counters. But I also have an office in the house, and sometimes I just want to do something there, but I don’t have a lot of space. I finally found a very workable solution that fits on a credenza and takes just around 14 inches of linear space.
How?
How can I pack the whole thing in 14 inches? The trick is to use only two boxes, but they need to be devices that can do a lot. The latest generation of oscilloscopes are quite small. My scope of choice is a Rigol DHO900, although there are other similar-sized scopes out there.
If you’ve only seen these in pictures, it is hard to realize how much smaller they are than the usual scopes. They should put a banana in the pictures for scale. The scope is about 10.5″ wide (265 mm and change). It is also razor thin: 3″ or 77 mm. For comparison, that’s about an inch and a half narrower and nearly half the width of a DS1052E, which has a smaller screen and only two channels.
A lot of test gear in a short run.
If you get the scope tricked out, you’ve just crammed a bunch of features into that small space. Of course, you have a scope and a spectrum analyzer. You can use the thing as a voltmeter, but it isn’t the primary meter on the bench. If you spend a few extra dollars, you can also get a function generator and logic analyzer built-in. Tip: the scope doesn’t come with the logic analyzer probes, and they are pricey. However, you can find clones of them in the usual places that are very inexpensive and work fine.
There are plenty of reviews of this and similar scopes around, so I won’t talk anymore about it. The biggest problem is where to park all the probes. Continue reading “The Short Workbench”→
