Tac for speed

rwilabee · Post by **rwilabee** » Fri Jun 15, 2012 11:24 pm

I was watching a video on youtube and they mentioned to use a tac for a speed check. What do you tac to. I was thinking I could chuck up an airplane prop and then use the tac I have for tacking my model airplanes.

Rich

dusty · Post by **dusty** » Sat Jun 16, 2012 6:07 am

rwilabee wrote:I was watching a video on youtube and they mentioned to use a tac for a speed check. What do you tac to. I was thinking I could chuck up an airplane prop and then use the tac I have for tacking my model airplanes.

Rich

That should work.

Wow. Times have changed. You tac your model airplanes. When I flew (combat control line) all I did was repair them and put back in the air fast as I could. Tuned the engine by ear.

wa2crk · Post by **wa2crk** » Sat Jun 16, 2012 8:45 am

I have a tach that is a contact type. You hold the rubber end of the tach shaft against the end of the rotating shaft and press the button to get the reading. There is also a non contact type that uses an IR beam and with this type you do not have to have the instrument come in contact with the rotating shaft. A small piece of reflective tape is put on the shaft and the IR beam is reflected from the tape and the device counts the rotations.
However if you have the prop type then use it. It will do the job.
Bill V

mountainbreeze · Post by **mountainbreeze** » Sat Jun 16, 2012 10:25 am

dusty wrote:.... When I flew (combat control line) all I did was repair them and put back in the air fast as I could. Tuned the engine by ear.

Wow, I had almost forgot about that era of my life. I used to fly combat control line too. My favorite was a Voodoo with a Super Tiger .35. Good times!

dusty · Post by **dusty** » Sat Jun 16, 2012 10:56 am

mountainbreeze wrote:Wow, I had almost forgot about that era of my life. I used to fly combat control line too. My favorite was a Voodoo with a Super Tiger .35. Good times!

I flew the VooDoo also but I used a Fox .35 with "centrifugal fuel injection". I don't know what that really was but it was the in thing for combat when I was doing this.

dusty · Post by **dusty** » Sat Jun 16, 2012 12:34 pm

To get back on to[pic - here is the tachometer that I bought. I ordered from an outfit in China and saved a little bit but it appears to be the same tachometer.

timsturnings · Post by **timsturnings** » Sat Jun 16, 2012 1:25 pm

I bought one of those tachometers from Ebay and it seems to work pretty good. I don't know how accurate they are but they serve my purpose. I now know the speeds on my ER with the speed changer.

dusty · Post by **dusty** » Sat Jun 16, 2012 2:05 pm

timsturnings wrote:I bought one of those tachometers from Ebay and it seems to work pretty good. I don't know how accurate they are but they serve my purpose. I now know the speeds on my ER with the speed changer.

I doubt that they are extremely accurate but for what we use them for in a wood shop, I think they are excellent.

The tachometer says my Mark V operates close to what the charts say at the various speed dial settings. I treat that as the standard.

lightnin · Post by **lightnin** » Sat Jun 16, 2012 8:42 pm

Something like this?
it's an eBay link and will go dead before the life of this thread
I'll edit the link if I come across something more permanent.

reible · Post by **reible** » Sat Jun 16, 2012 8:57 pm

I was just going through some ebay papers today and noticed that the one I purchased on 6/7/11 was $4 with $8.77 postage (total $12.77).

Look familiar?

[ATTACH]17706[/ATTACH]

It seems to work fine and has lasted a year, how close it measures is close enough for me.

Ed