Mannessmann Tally MT660 Line Printer 

When I moved to Seattle in 1979, I moved here for a job as a mechanical engineer with Tally Corporation in Kent, WA. I helped design a new, high speed (600 lines per minute) impact dot matrix printer. I was responsible for the paper feed system including the paper "tractors" and the mechanical drive system. About the first six months was spent researching the best way to move paper as fast as it needed to go. (this printer was twice as fast as the previous fastest Tally printer).

I also helped design the structural frame of the printer, the "shuttle" system and the cast metal frame that supported the "hammer bank". We had a large team on this product - about 8 mechanical engineers, two electrical engineers and three software engineers plus several drafters and PCB layout technicians.

Fast impact printers are pretty much dinosaurs these days, but they do have their niches for low cost, high volume printing. When it was brought out onto the market in 1982, this printer sold for about $10,000.

This is an ad for the printer. It's a very nice "cutaway" drawing that accurately shows many of the internal mechanical parts.

During the design of the "shuttle mechanism" that moves the hammer bank back and forth about 40 times per second, I came up with a novel idea on how to adapt a conventional "rotary" DC motor to provide a linear motion to the hammer bank. I designed a prototype of this and built one at Tally and found that it worked pretty well. However, we decided to stay with the "voice coil" linear motor (essentially a mother of a sub-woofer). But we did apply for a patent. The image to the left is the cover page of the patent granted to Tally with me as the inventor. Geez - now I'm famous!

Last updated: November 09, 1996