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In 1977, I entered college with a major in Tool and Die and Mechanical Engineering. While there, I had the opportunity to create several new hand pieces for the worlds first pneumatic engraver the gravermister invented by my father's friend John Rohner to replace the orginal one. These new hand pieces were
palm-sized rather than long like the hand piece that came with John's orginal invented machine. This was beneficial for smaller detailed engraving as well as providing improved control. Then in 1979, my father made an electronic circuit to oscillate and adjust the speed of a solenoid valve. Air was run through this valve to produced blow-pulses rather than suction-pulses. My father and I built numerous hand pieces for this adjustable positive pulse generator, and I used that machine for my work up to 1999. In an interview for the December, 1981 NebraskaLand magazine, my father’s machine was mentioned and a picture of it can be seen on the back corner of the engraving bench on page five of the article. NEBRASKAland.pdf. It is the gray box in the right back corner of the bench.
Left: Picture of three handpieces made in 1979 for my father's machine.