Another stange find of which me nor the seller knew what it was. I gave a quarter for it, and figured it was some sort of exacto knife blade holder. When I found out it was a mechanical tachometer, I was and still am surprised. It may fall in the "Gimmick" tool catagory, but I'm a sucker for these  unusual tools. The idea behind it, is to lay the nose of it on a motor, then extend the deflection rod until you get the maximum deflection. When you get the max. deflection, you read the scaled number on the body, and multiply it by 1,000 to find the RPM! LOL! Anyone else ever see, or use one? PS. If you click on the last pdf, you can see the brochure and how it works.

Wayne

BTT

never seen one of those wayne,any date for it?
brian

I believe it is a 1960's era tool, and from the pdf brochure I posted, may still be manufactured.

Wayne

I like it and would have to test it myself

Interesting tool. The tuning fork principal was used  for frequency measurement on generators and such, but with a set of fixed tuning forks. Never seen a device with a variable length tuning element, very clever really.