Inside a cheap set of eBay digital calipers

[PeterT]

Interesting dissection if for no other reason generally how they work.

 

[Tom Kitta]

Amazing at how far this tech has gone and how good cheap Chinese calipers are! If you actually know what you are doing and try hard to apply same pressure all the time you can easily get repeated results to about 2 thou or even 1 thou.

 

[PeterT]

It would be interesting to see what is inside a high quality caliper for comparison. Where did they cut corners on the board & why do they eat batteries at an alarming rate? One would think if they just reverse engineered the board they wouldn't be so bad. Maybe its about the quality of components, I dunno.

I found it interesting when he did the repeated end to end zero minimum to maximum thing & got the repeated display values. But it would have been better to compare the physical distance with an independent vernier. ie. maybe that's just where the display null defaults & has little to do with reality. Also interesting is the 'unused' features on the board that looks like they would be for other buttons. I guess its like calculators, phones & other electronic devices. The first ones are expensive & eventually they are so cheap they come free in the bottom of a cereal box.

A cheapo plastic one like he shows might be good for specialized applications where you could just cut the jaws off, cannibalize the parts & measure something reasonaly accurate. Maybe in a dirty environment like grinding. I cant think of a good application off hand. But I did try cutting the jaws off a cheapo steel one with my Dremel disk for a tailstock vernier & it didn't go well. The metal is actually decently hardened so you have to control the heat & grit.