Frame from Measure the mass of an eyelash with a DIY microbalance Plays with YouTube's privacy-enhanced embed

Measure the mass of an eyelash with a DIY microbalance

Open on YouTube First HN thread

1 HN user recommended this demo in 1 different month between 2018 and 2026.

2007–2026
1 recommendation 3 citations HackerTube score 1

Pointed to as proof that you can weigh micrograms cheaply at home, and as a clear breakdown of how such a scale works.

Ben Krasnow of Applied Science builds a DIY microbalance from an analog panel meter with an optical servo loop. It reaches about 5 micrograms of precision and is used to weigh a single eyelash at around 35 micrograms.

Pull quote: “YouTube just dug up a a real nice breakdown that Ben Krasnow did” (HN, 2018)

Also tagged: diy microbalance, precision measurement, servo loop, lab equipment, diy, analog meter

What Hacker News said

4 labeled comments from the HN archive; up to 20 are kept per video, favoring different commenters. Each one links back to the original thread.

Recommends jcims December 2018 under Making Penicillin at Home
Real nice breakdown of a DIY microbalance by Ben Krasnow.
Saw this DIY one a few years back on youtube, looks like the Erowid one, thought it was a neat build - [link] YouTube just dug up a a real nice breakdown that Ben Krasnow did - [this video]

Citations, criticism and jokes

Cites it mikewarot July 2023 under An Invitation to a Secret Society
Example of cheaply weighing micrograms.
Measuring things precisely is way cheaper than it's ever been. You can weigh micrograms without too much effort.[1] You can buy time/frequency standards for $200 or so that time to the national standards.[2] Float glass is a cheap and relatively flat surface plate that you can buy almost anywhere. Lasers, detectors, computing, everything is dirt cheap compared to the past. If you have something you want to make, or measure, this is likely the easiest time ever to do so. Don't worry about being at the leading edge, just do something, have fun, and you might be the first to notice some weird little quirk that turns out to be important. [1] [this video] [2] [link]
Cites it s0rce May 2025 under Strain gauge made out of PCB
Comparable to a relative's homemade microgram scale.
My dad built one with an electromagnetic coil many years ago, can't find the design, capacity was limited but had 100? microgram resolution, maybe similar to this applied science video [this video] but I think simpler. maybe something like this: [link] [link] I found some old emails about the scale from 2005/6 but can't find the link and it would probably be gone anyways.
Cites it pvillano January 2026 under A4 Paper Stories
Related to calibrating tiny scales using paper.
Paper's uniform mass per area makes it useful calibrating very tiny scales. 1mm² of 80 gsm paper will weigh about 80 micrograms. "Measure the mass of an eyelash with a DIY microbalance" by Applied Science [this video]

Keyboard shortcuts

/
Search
j k
Next / previous video in a list
Enter
Open the focused video
l
Like (on a video page)
w
Watch later (on a video page)
?
This help
Esc
Close