good tool....

[sly the dogman]

Is a tachometer a good tool to have in my tool box ?

[chopstick]

You can do without it, but it is nice to have one.

[xspare]

and if you have a smart phone you might not even need any space in the tool box or assistance to do it.

http://itunes.apple.com/us/app/helit...322478561?mt=8

[TheBum]

Originally Posted by xspare

and if you have a smart phone you might not even need any space in the tool box or assistance to do it.

http://itunes.apple.com/us/app/helit...322478561?mt=8

I still don't trust audio tachs. There are too many factors that can throw off the reading.

I would highly recommend a Bantam Checkmaster II. It's a jack of many trades: servo tester, photocell tach (for airplane props), optical tach (for helicopter rotors), and contact thermometer (with the optional sensor). And, unlike the SkyTach, it actually has a way to power it off manually without removing the battery. I think the viewing window for the optical tach is a little bigger than the SkyTach's too.

There is one caveat: the stock internal NiMH battery will not hold a charge if you just leave the device in your field box unconnected to charging power. However, you can construct an Eneloop pack for it that will hold a charge for months. I bought a pre-made pack and crimped a connector on it.

[xspare]

For as often as I need it, to verify governor settings, I'm happy enough to trust my audio tach:

[ame]http://www.youtube.com/watch?v=giNRksfMpCQ[/ame]

[w4llet]

Originally Posted by TheBum

I still don't trust audio tachs. There are too many factors that can throw off the reading.

Indeed!

I have a phone app that throw off the reading always. I do never have same results back, even in same head speed.

Have no idea how accurate it is.

[Rob43]

Although I have a Model Avionics Sky Tach, I more often don't require it's precision, and I find not many of the airplane guys at my field use it very well. So, I simply use an inexpensive propeller tach. I found it works well by stuffing the end into one of the rotor blade slots of the foam blade keeper. I lay it on the takeoff area adjacent to the model, positioned so I can read it from my piloting position a few feet away. No hands, no help. I can see how much difference I am realizing with pinion tuning. If flying with a governor, it's close enough for me. No need to hover. You can apply some negative pitch to load up the drive if desired.