Digital calipers

[ed440 at mindspring.com]

It's good to make it a habit to "re-zero" before each use.
If accuracy to the thousandth matters, Ron's squeeze is good, and 3 quick measurements will confirm the reading, moving and turning the "measuree" between each reading.  Best is if the measuree is held by nothing but the caliper so there is no diagonal distortion. If that's not possible, squeezing from the jaws like Ron says, let go of the tail of the caliper so the jaws can align to the pin or whatever.
Measuring oval front pins you can rock the caliper back and forth and watch the display for the smallest measurement.
Did anyone mention the value of being able to "zero" on a pin or dowel, then go to the drill case and select the "zero" drill? This can also be done with punchings and cloth and other such joys of the piano shop.
My tired eyes are very grateful for this gadget.
Ed S.

-----Original Message-----
>From: Ron Nossaman <rnossaman at cox.net>
>Sent: Jul 16, 2006 12:28 AM
>To: Pianotech List <pianotech at ptg.org>
>Subject: Re: Digital calipers
>
>
>> It is important to develop a ?feel? for your micrometers and calipers 
>> when closing them against your specimen and closing them.  Without this 
>> important control, you will not get consistent, dependable 
>> measurements.  BTW, these instruments must be stored in their closed 
>> position to keep them clean and corrosion free.
>> 
>> Paul C
>
>I bought one of the $15 Harbor Freight digitals a year or so 
>ago, and have been more impressed with it than I expected to 
>be. I've found, with either dial, vernier, or digital 
>calipers, that the thumb wheel is definitely not your friend 
>if you need accuracy. Accuracy increases considerably and 
>repeatably by squeezing the jaws onto the measuree by finger 
>pressure directly on the jaws, on either side of said 
>measuree. This takes the flex out of the system, gets you into 
>the designed intent of usage of the system, and closer to a 
>real and actual dimensional figure than the usual vague 
>committee approximation we typically expect from calipers. Not 
>that it ain't possible (nay, likely) to screw up a given 
>measurement taken with any tool we care to name, but there are 
>approaches and methods that limit and minimize erroneous 
>measurement. Erroneous deductions extrapolated from inaccurate 
>measurements are, unfortunately, unavoidable and, largely 
>(also unfortunately), inevitable.
>
>We loves our tools, however, despite their limitations in 
>overcoming our own limitations.
>
>At least I does...
>Ron N