Forum rules
Welcome to the Leverguns.Com General Discussions Forum. This is a high-class place so act respectable. We discuss most anything here other than politics... politely.
Please post political post in the new Politics forum.
A question for any of you machinists or gizmo-ists:
I just bought (finally) a metal digital caliper to replace my plastic 'dial' one...
What exactly enables the digital counter to 'measure' on a digital caliper?
I want to know partly because of curiousity, and partly because I'd like to be sure not to scratch or damage whatever it is that the module reads. I don't see any scoring or gear teeth or pattern but I assume there must be something that is being counted as the caliper slides apart.
Just curious.
It's 2025 - "Cutesy Time is OVER....!" [Dan Bongino]
An electronic scale ( inside the head ) the good ones will take a lot of abuse.
I have three high grade 0-.100 dial /mechanical ones, they have all gone to repair at 1 time or another, in good shops it is considered normal wear and tear and the shop pays for it.
Just keep it clean & don't throw it around, your children will use it after you are gone.
I'm with Hobie I just can't seem to trust digital junk. I have several dial calipers, (Lyman--Starret--and some Japanese name I can't spell.) Cell phone?? My wife got me one about 5 years ago. When she handed it to me, I said, "just set it on the micro-wave oven." Well, its still there ----------------------Sixgun (livin' in the past!)
No one fussin up to vernier calipers? My boss insisted I have a cell phone. Company pays the bill and I carry it. Doesn't work most places where I don't want to be disturbed anyways.
I like my digital calipers.. handy to convert inches to mm.. can set zero on a cartridge case then measure the others and read variances much more simply between cases.. Only thing I ever had a problem with was using them after being in the cold car over night... they didn't work until the warmed up enough.. Actually that's a good thing I guess because being that cold would prolly give a bad reading with a dial caliper.. But I too would also like to hear how the actual electronic counting is done to give a measurement like AJMD429 asked in the first place.
"IT IS MY OPINION, AND I AM CORRECT SO DON'T ARGUE, THE 99 SAVAGE IS THE FINEST RIFLE EVER MADE IN AMERICA."
WIL TERRY
In the vernier scale, they are most often encounterd in the larger versions.
In my experience used to measure the machined parts on large commercial aircraft engines, earth moving equipment, etc.
The working part, called a linear encoder, is basically a vernier scale with the human eye replaced by an optical or electronic read head. On the cheaper calipers the fixed scale has a pattern of lines etched on the back. Inside the read head is a circuit board carrying a similar pattern of lines. These patterns form tiny capacitors and, as the read head moves, the charge is measured and translated into distance. Digital calipers are very convenient to use but a good dial caliper in skilled hands will often give better accuracy and precision. The best linear encoders use optical read heads but then we are talking bigger bucks. The ones I use in my designs have a resolution of 0.1 microns (0.004mils)and cost roughly as much as two Shiloh Sharps.
Perry Owens
That's pretty acurate! With my Chinese lathe, 0.001" is about as acurate as I can repeat (maybe). I need more practice with it as I haven't had it that long.
With my Chinese lathe, 0.001" is about as acurate as I can repeat (maybe).
If it's a 7 x 12 mini-lathe that's about as good as it gets. Those thing are tremendous value for money - I don't know how I ever managed without mine. I shoot vintage guns in odd calibers and use it for making parts, loading accessories, trimming cases etc. The savings in time and cash are great, particularly here in the UK where gun-related stuff is not so easy to get.
Perry Owens
They are neat tools. I use them alot at work for measuring shims and what not. I just got one at the house for the reloading stuff(Frankford Arsenal), it's a bit stiff but will work just fine. I prefer a good micrometer any day for accuracy though.
Qui tacet consentit. (silence implies consent) The Boring Blog
I know 20cows. I've been following your posts on this and getting a great deal of vicarious pleasure from your activities. I've only one complaint. Too few reports!
Sincerely,
Hobie
"We are all travelers in the wilderness of this world, and the best that we find in our travels is an honest friend." Robert Louis Stevenson
to replace my plastic 'dial' one... 
I just can't seem to trust digital junk. I have several dial calipers, (Lyman--Starret--and some Japanese name I can't spell.) Cell phone?? My wife got me one about 5 years ago. When she handed it to me, I said, "just set it on the micro-wave oven." Well, its still there 
