How to Make a Digital Height Gage
During 1992 my uncle, a tool maker, gave me several older copies (1978) of “Live Steam” magazine. Needless to say I promptly got ahold of Village Press and became a subscriber of LS, then on to HSM, PIM, and put the topping on the cake with several of the VP hardbound collections. (My whiskey, tobacco, and wild women money)
The article that probably interested me the most was one by the late Frank McLean on the construction of parts to convert a digital caliper into a height gage. This was reprinted later in the hardbound “The Shop Wisdom of Frank McLean”.
The young guys in my shop class would sort of chuckle when I broke out a pocket magnifier to read a vernier gage. Now I need not. I had finished my shop project early and a very cooperative instructor allowed me to utilize the college’s equipment and a couple of small scraps to go ahead and make the parts. The completed gage worked very well for me.
In a couple of minutes I can have the caliper back for hand use. The only modification to the caliper is to file a small flat on the top of the upper jaw where the setscrew (grubscrew) holds an arm on. Two setscrews hold the caliper in the base block. I made the slit in the base wide enough to take the lower jaw of the caliper plus some protective shim stock. Then I promptly tried it out without the shims and left two nice marks on the jaw to remind me that haste makes waste. Per the drawing I relieved the bottom of the base about 1/32″ or so.
It is nice to be able to put the pointer on the base or anything else and zero it with the tap of a button. Then to go to whatever and determine the relative height in inches or millimeters. Accuracy of course is determined by the investment in the caliper. Mine is $60.
Author: Paul Pierce