A tale of two gauges

Dad's surface gauge, top, contrasts with his much older carpenter's gauge.

While showing me his machinist's toolbox in his basement one day, Dad pulled out a surface gauge. I was very intrigued with its sculptural qualities and beautiful machining, and was astounded when Dad explained that he had made it himself.

"You want it?" he asked, nonchalantly.

"Sure!" I gasped.

It was a treasure I set aside when we donated the toolbox and its other contents to the Western Canada Aviation Museum. Sorry, but it's mine. 

Dad couldn't recall just when he had made the gauge, sadly, so we don't know whether it was a student project in Winnipeg, or made while studying tool making in Trenton with the RCAF. Perhaps he made it overseas in 1945, after peace was declared and he was waiting to return home.

I couldn't help but compare it to the carpenter's gauge in Dad's woodworker's toolbox. The wooden gauge had been his father's, and may well have belonged to Pete's own father or grandfather before him. Dad certainly used it himself, and considered it a handy tool, rather than the piece of history I consider it to be.

It is interesting to compare the two gauges as metaphors for Dad and his father. The tools represent the progression from straightforward wooden construction of an earlier time, to the advanced aeronautical engineering Dad mastered.

His surface gauge, from its knurled knobs to the sphere decoration at the top, exemplifies Dad's impeccable precision and skill as a tool-maker.

It's easy to understand the carpenter's gauge, less so the surface gauge, so here's a brief lesson from one of Dad's own textbooks, Tool Making, by C. B. Cole.

According to the textbook (American, thus "gage"):

Universal Surface Gages. The surface gage is a handy tool in laying out jigs, fixtures, and other tools. It is also used extensively in setting up jobs on shapers, planers, and milling machines. The surface gage used in conjunction with a dial or pointer indicator has become almost indispensable to the average tool or gage maker.

Various applications of a surface gauge (courtesy L.S. Starrett Company)

In using the surface gage to lay out work for the planer or shaper, a combination square is often used. In this case the scriber on the surface is set to the height desired by means of the scale on the combination square. The height is then transferred to the work to be machined by using the surface gage scriber to mark a line. This is done by placing the work on the surface plate and moving the surface gage to the distance required to be marked.

Left: surface gage used in conjunction with combination square.
Right: Surface gage used to lay out a jig (courtesy Brown & Sharpe Mfg. Co.)

The surface gauge is still an indispensable tool in a machinist's collection. These days they are also used for stop-action animation. Their fine-tuning allows precise control, either way.

Fine and precise, just like Dad.