Even though it’s not the right tool for the job, we’ve all used a flat head screwdriver for other purposes. Admit it — you’ve pried open a thing or two with that one in the toolbox that’s all dirty and dinged up anyway. But oftentimes, screwdrivers just aren’t thin enough. What you need is a spudger, which for some reason, seem to only come in plastic. Blame our disposable times.
In a relevant break from building electronics, [lonesoulsurfer] took the time to craft a set of spudgers and such from secondhand silverware. These are all made from spoons and butter knives sourced from a thrift store. For the spoons, [lonesoulsurfer] removed the heads with an angle grinder, shaped them on a belt sander, and thinned them out until they were spudger-slim. After doing the same with the handle end, [lonesoulsurfer] polished up the new tools on the wheel with some compound.
Not all of these are spudgers — some are destined to scrape, and others for lifting badges and decals. But they all live in harmony in a handy carrying case. Check out the build video after the break.
Well, it’s done. After weeks of trawling Craigslist, an hour-long phone call with an intelligent stranger about a different machine that wasn’t going suit my needs, and a two-week delay while the seller and I waited out their unintentional COVID exposure, I am the proud new owner of a vintage Consew 206RB-3 industrial sewing machine.
So far, it is exactly what I wanted — at least a few decades old, in decent shape, built by a reputable maker, and it has a clutch motor that I can upgrade to a servo motor if I wish. I even like the color of the head, the table, and the little drawer hiding on the left side. Connie Consew is perfect!
Decidedly Not Portable
The internet was right — these things are heavy. According to the manual, the machine head alone weighs 25.5 kg (56 lbs). The motor probably weighs another 50-60 lbs. There’s a small wooden peg sticking up from the table that has the job of holding the head whenever it is tilted back for maintenance or bobbin changes. I’ll admit I didn’t trust the little peg at first, but it does a fine job of supporting all that weight on a single point of contact about an inch in diameter.
Crimp connectors provide an easy and convenient way to connect electronics while still allowing for them to be removed and swapped without having to reach for a soldering iron and desoldering wick. While browsing one’s favorite cheap shopping site, you may get the impression that all one has to do to join the world of crimp-awesome is order a $20 crimp tool and some assorted ‘JST’ and ‘DuPont’ (a Mini-PV clone) connectors to go with it. After all, it’s just a bit of metal that’s squeezed around some stripped wire. How complicated could this be?
The harsh truth is that, as ridiculous as the price tag on official JST and Mini-PV crimping tools may seem at hundreds of dollars each, they offer precise, repeatable crimps and reliable long-term stability. The same is true for genuine JST, Mini-PV and Molex connectors. The price tag for ‘saving a buck’ may end up being a lot higher than the money originally saved.
A lamp used to be simple thing: just stick a filament in a glass bulb, pass a current through it and behold! Let there be light. A bigger lamp meant a larger filament, taking more power and a larger envelope. Now we’ve moved on a bit, and it’s all about LEDs. There really isn’t such a thing as ‘just an LED,’ these are semiconductor devices, made from relatively exotic materials (OK, not just plain old silicon anyway) and there is quite a lot of variety to choose from, and a bit of complexity in selecting them.
For [Torque Test Channel] the efficiency of conversion from electrical power to radiant power (or flux) is the headline figure of interest, which prompted them to buy a bunch of lamps to compare. To do the job justice that requires what’s known in the business as an integrating sphere (aka an Ulbricht sphere), but being a specialist device, it’s a bit pricey for the home gamer. So naturally, they decided to build the thing themselves.
Coating the inside of the foam sphere took several attempts.
Firstly they did the sensible thing, and shipped off their test units to a metrology lab with the ‘proper’ equipment, to get a baseline to calibrate against. Next they set about using some fairly common materials to construct their sphere. The basic idea is quite simple; it has a uniform diffuse internal surface, which ensures that all photons emitted by a source can be measured at the appropriate measurement port, regardless of the angle they are emitted from the source. This way, the total radiated power can be determined, or at least estimated, since there will be a degree of absorption.
Anyway, after a couple of false starts with coating the internal surface, they came to the conclusion that mixing barium sulphate into the paint, and then a bit of a rub-down with sandpaper, gave the required pure white, diffuse surface.
The results from their testing, using a lux meter inserted into one of the other ports, showed a pretty good correspondence between their measured lux figure and the lab-determined lumens figure. Since one lux is defined as one lumen per square meter, they seemed to get lucky and found a consistent ten-to-one ratio between their observed value and the lab. This factor will be simply due to the physical setup of their contraption, but an encouraging result so far anyway. And what about the bottom line? Did those test units deliver their promised lumen output? It would seem that they pretty much did.
Now, we know what some of you are going to say — “Oh man, not another programmatic CAD tool, what’s wrong with OpenSCAD?” — and you may be right, but maybe hold on a bit and take a look at this one, because we think that it’s now pretty awesome! OpenSCAD is great, we use it all the time round these parts, but it is a bit, you know, weird in places. Then along comes CadQuery, and blows it out of the water ease-of-use and functionality wise. Now, we’ve seen a few mentions of CadQuery over the years, and finally it’s become a full-blown toolset in its own right, complete with a graphical frontend/editor, CQ-editor. No odd dependencies on FreeCAD to be seen! That said, installing FreeCAD is not a bad thing either.
The goal is to have the CadQuery script that produces this object be as close as possible to the English phrase a human would use.
Often, we need to power a 5V-craving project of ours on the go. So did [Burgduino], and, unhappy with solutions available, designed their own 5V UPS! It takes a cheap powerbank design and augments it with a few parts vital for its UPS purposes.
You might be tempted to reach for a powerbank when facing such a problem, but most of them have a fatal flaw, and you can’t easily tell a flawed one apart from a functioning one before you buy it. This flaw is lack of load sharing – ability to continue powering the output when a charger is inserted. Most store-bought powerbanks just shut the output off, which precludes a project running 24/7 without powering it down, and can cause adverse consequences when something like a Raspberry Pi is involved.
Understandably, [Burgduino] wasn’t okay with that. Their UPS is based on the TP5400, a combined LiIon charging and boost chip, used a lot in simple powerbanks, but not capable of load sharing. For that, an extra LM66100 chip – an “ideal diode” controller is used. You might scoff at it being a Texas Instruments part, but it does seem to be widely available and only a tad more expensive than the TP5400 itself! The design is open hardware, with PCB files available on EasyEDA and the BOM clearly laid out for easy LCSC ordering.
Over on Hackaday.io, user [Tomasz Jastrzebski] has designed a tidy-looking custom controller for driving temperature-controlled soldering irons. The design is intended to be general purpose, capable of operating with irons rated for different voltages and probe type, be they thermocouple- or thermistor-based. Rather than integrating a power supply, this is handled by an external unit, giving the possibility of feeding this from a variety of sources that are not necessarily tied to the grid.
Hardware-wise, we’ve got the ubiquitous STM32 microcontroller in charge of the show, with a nice front end based on the INA823 instrumentation amplifier, referenced to a REF2030 precision voltage source. The input stage is configured as a versatile Wheatstone bridge input circuit, giving plenty of scope for tweaking.
There are a few extra features in the design that aren’t necessarily needed for a soldering iron driver, such as RTC support, complete with supercapacitor backup, but then this doesn’t have to drive a soldering iron, it could drive any DC heater with temperature feedback. With a change in firmware, this could serve other tasks. One potential feature that springs to mind — have the unit automatically power down at a certain time of day in case it was left on accidentally.
The schematic has a lot of relevant detail — in that many parts have a good list of alternatives, presumably because of the semiconductor shortages — which is a good habit to get into if you ask us. Many of us involved with manufacturing have been doing this for years, as it makes sense to give the assembly house the extra options, but this really is basically mandatory practice now.
Firmware for the STM32G0 series microcontroller is based on the STM32 HAL, keeping it simple, with a Visual Studio Code project provided for your convenience. All hardware (KiCAD) and firmware can be found on the project GitHub.
