Do you calibrate your digital meters? Most of us don’t have the gear to do a proper calibration, but [Mike Wyatt] shares his simple way to calibrate his DMMs using a precision resistor coupled with a thermistor. The idea is to use a standard dual banana plug along with a 3D-printed housing to hold the […]
At first glance, [RobBest]’s constant current source looks old school. The box is somewhat old-fashioned, featuring switches and binding posts. Most importantly, there’s a large analog meter dominating the front panel. Then you notice the OLED display, and you know something’s up. The device can source or sink a constant current. In addition, it features […]
Generally, you think that if you pay more for something, it must be better, right? But that’s not always true. Even if it is true at the lower end, sometimes premium brands are just barely better than the midrange. [Project Farm] looks at a bunch of different calipers — a constant fixture around the shop […]
Having a chiller is often essential for the chemistry laboratory, but what if you’re somewhere without easy access to water, nevermind a mains outlet to plug your usual chiller into? In that case you can build a portable one that will happily run off the 12 VDC provided by a mobile source like the accessory […]
Reloading filament on a 3D printer is hardly anyone’s favorite task, but it’s even worse when you’re trying to shove stiff filament down a long and winding Bowden tube. Enter the speed loader from [Mr Flippant], which aims to take the pain out of this mechanically-frustrating chore. The design is simple enough. It’s a small […]
Frequency! It’s an important thing to measure, which is why [Jacques Pelletier] built a frequency counter some time ago. The four-function unit is humble, capable, and also an entry into our 2025 One Hertz Challenge! The build began “a long while ago when electronic parts were still available in local stores,” notes Jacques, dating the […]
Over on his YouTube channel the vivacious [Stephen Hawes] tells us that we never need to buy solder stencils again! A big claim! And he is quick to admit that his printed solder paste isn’t presently quite as precise as solder stencils, but he is reporting good success with his technique so far. [Stephen] found […]
Repairing radios was easier when radios were simple. There were typically two strategies. You could use a signal tracer (an amplifier) to listen at the volume control. If you heard something, the problem was after the volume control. If you didn’t, then the problem was something earlier in the signal path. Then you find a […]
CNCs come in many forms, including mills, 3D printers, lasers, and plotters, but one challenge seems universal: there’s always a project slightly too large for your machine’s work envelope. The Compass CNC addresses this limitation by incorporating the operator as part of the gantry system. The Compass CNC features a compact core-XY gantry that moves […]
3D printing has simplified the creation of many things, but part of making something is knowing just how much you can rely on it. On the [BubsBuilds] YouTube channel, he built a cheap rotary table and then walked through the process of measuring the error inherent in any rotating system. Starting with a commercial rotary […]