Category Archives: load cell

Does Your Home Assistant Know When You are Sleeping?

It always gives us a sense of wonder when we realize that what would be a simple task for a human child is a big deal for a computer. For example, if you asked someone if you or someone else was in bed, that’s a pretty simple thing to check. …read more

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Posted in Arduino Hacks, bed occupancy, home-assistant, load cell | Leave a comment

Quartet of SMD Resistors Used to Sense Z-Axis Height

Here’s a neat trick for your next 3D-printer build or retrofit: a Z-axis sensor using a DIY strain gauge made from SMD resistors. We’re betting it could have plenty of other applications, too.

Conventional load cells, at least the ones you can pick up cheaply from the usual sources or harvest from old kitchen or bathroom scales, are usually way too big to be used on the extruder of a 3D-printer. [IvDm] wanted to build a touch sensor for his Hybercube printer, so he built his own load cell to do it. It consists of four 1000 ohm SMD resistors …read more

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Posted in 3d Printer hacks, attiny85, bed leveling, hx711, load cell, smd, strain gauge, wheatstone bridge, z-height | Leave a comment

Instrument Packed Pedal Keeps Track of Cyclist’s Power

Exactly how much work is required to pedal a bike? There are plenty of ways to measure the power generated by a cyclist, but a lot of them such as heavily instrumented bottom brackets and crank arms, can be far too expensive for casual use. But for $30 in parts you can build this power-measuring bike pedal. and find out just how hard you’re stoking.

Of course it’s not just the parts but knowing what to do with them, and [rabbitcreek] has put a lot of thought and engineering into this power pedal. The main business of measuring the force …read more

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Posted in hx711, load cell, power, power meter, qi charger, strain gauge, transportation hacks, Wemos | Leave a comment

Electronifying A Horror Fraught Hydraulic Press

[Josh] is replacing the springs in his car’s suspension. He wanted to know the travel rates of these springs, but apparently, this is a closely guarded trade secret in the industry. One company did manage to publish the spring rates, but they weren’t believable. Instead of taking this company’s word, [Josh] built a spring tester.

The theory behind a spring tester is pretty simple: apply a force to a spring, measure it, then measure how much the spring has traveled. Or compress a spring an inch or so, measure the force, and compress it some more. Either gets you the …read more

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Posted in load cell, spring, suspension, tool hacks, transportation hacks | Leave a comment

Bandsaw Tension Gauge Uses Raspberry Pi And Load Cell

No matter what material you’re cutting, getting the blade tension right is one of the keys to quality cuts on the bandsaw. Unfortunately, most bandsaws come with only a rudimentary tension gauge, and while there are plenty of tricks for measuring blade tension indirectly, nothing beats a digital blade tension gauge for repeatable results.

Despite being an aftermarket accessory for his beefy Hitachi CB-75F bandsaw, [Stephen B. Kirby]’s Pi-based tension guide looks like an OEM product. Housed in a sturdy case and sporting a sealed membrane keypad and four-line LCD display, the interface electronics are pretty straightforward. The tricky bit …read more

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Posted in load cell, Raspberry Pi, tool hacks, tools | Leave a comment