Engine tacho calibration

[tnowak]

Anyone know where I can get the calibration checked on a mechanical engine tacho instrument?
Thanks

Tony Nowak

[C Rule]

Tony
One possible solution is to remove the Tacho and drive it with a lathe of known rotational speed.
Or borrow a stroboscope from the micro light people down the way and try it in situ. That's what we did after doing a check calibration of their strobe using a a calibrated one we borrowed from elsewhere. The agreed to within 5rpm
Colin

[Ian Melville]

Hi Tony, I have used a model aircraft optical tacho on our Vagabond to check the tacho. Our engines are right at the bottom of the scale, so not perfect. They do give a sanity check for little outlay. Can be used in flight as well.

[tnowak]

Thanks all. I have an optical checker but it only gives a resolution of 100 RPM (I think).
I have found a company, Speedycables, that says they can do a bench test/calibration. They also seem to do everything associated with cable driven instruments.
http://www.speedycables.com

Tony

[Ian Melville]

Mines the same, that's why I said for a sanity Check.

[Frank Parker]

I use an app on my Droid phone, works well

[johnmichie]

Frank
I found loads of Android apps when typing in tachometer, many are not tachos in the sense that they measure rpm, and those that seem to are accoustic. Which one do you use.

John

[Frank Parker]

The one I have currently is just identified by the icon as RPM Gauge, but on the PlayStore it is called Accoustic Tachometer (RPM) and written by Javier Yanez. You can set it for four cylinders and 4 stroke cycle. Resolution is claimed at 40 rpm. In my AA5 with the original 1972 tacho the two agree remarkably well, to my amazement as most seem to read low at that age.