4 ms·
Be sure to watch Big Clive's video that's linked in the article. It's amazing how cheap digital calipers have gotten, and how accurate they are at that price. T
by userbinator 2y ago
Be sure to watch Big Clive's video that's linked in the article. It's amazing how cheap digital calipers have gotten, and how accurate they are at that price. They probably use a 4-bit MCU or an ASIC to do the calculations and output the data --- both to the screen, and an often-hidden serial port. The use of a non-absolute encoding leading to drift, and the higher standby power consumption which was distinctive of the infamous battery-eating Mitutoyo clones, seems to have been largely solved within the past few years. There are even solar models available for not much more.
- XorNot 2y agoI would love some solar powered calipers. "I'll wing it" measurements for me are usually powered by "god damn it, do I even have any more CR2032's? Is the battery cover pressing down enough? Screw it where's a ruler..."
- userbinator 2y agoSolar calipers are around US$10 at the usual far-East online shops.
- moreati 2y agoRecommend you take the CR2032 out when not using the calipers. Cheap/no name ones (atleast those sold 5-10 years ago) have a relatively high standby current, even when the LCD screen is off.
- janci 2y agoI just flip the coin cell around so it stays in the device but does not deplete (reverse polarity but in fact the contacts will not touch the battery poles so no harm).
- DoctorOetker 2y agoWould you happen to know the current draws for the older and newer designs? I would like to check if mine are worth replacing (since I dutifully remove and store the battery in the designated holder in the case I can't rely on durability comparisons because it would depend on usage patterns).
- moreati 2y agoI don't know the current draw of either. I don't know if newer designs are better, I only have one I bought around 10-15 years ago. For mine a bettery left in the calipers depletes within a few months, without use.
- telgareith 2y agoEven my cheap 100% plastic calipers have been running for 2years. And yes they cost $100 but my good calipers have been running for 5years or so
- xyzzy123 2y agoGet a Mitutoyo, it'll be accurate AND the battery will last 5 years. It only hurts once. Cheap calipers hurt every time you use them :/
- polishdude20 2y agoIt would be super cool to do some sort of energy harvesting when you move the calipers open and closed.
- cjaackie 2y agoYes I remember seeing this video when I came out and he explains it quite well. I don’t know who was the first to use a linear encoder in a digital caliper but it’s ingeniously simple. And omg have I gone through some LR44 with my battery eating clone as well, good to know I’m not alone.
- radlad 2y agoI just pull the battery out before putting it away.
- Tempest1981 2y agoThis blog shows a better capture of the pulse-train waveforms: https://www.grant-trebbin.com/2014/04/digital-calliper-teardown-and-repair.html https://www.grant-trebbin.com/2014/04/digital-calliper-teard... Which I guess is from here: (2006) https://web.archive.org/web/20060923040306/http://www.yadro.de/digital-scale/working.html https://web.archive.org/web/20060923040306/http://www.yadro....