Tachometer Problems
 

Hey Everyone,

I have been trying to get some readings on my Fuji .099, but I can't seem to get any sort of reliable numbers. I have angled the tachometer (picture of the one Ihave is below)in all directions, but still seem to get numbers that are all over the place.When I putthe tachometer directly in front of theblade I gota one digit number.When I movedthe tachometer soit wasangled about45 degrees to the blade, Igot much higher numbers,but theyare jumping all over the place. Does anyone have any explanation or remedy for this problem?

Thanks,
KP

RE: Tachometer Problems
 

Always take your readings from behind the prop and with the Sun behind you. My $20 Chinese tach gives out spurious false readings, but it settles into a steady readout sooner or later. Don't be afraid to get close to the prop, but you don't have to be right on it.

RE: Tachometer Problems
 

And if you're testing in a garage, use a flashlight set up to shine through the prop arc...
You need a DC powered light source if you're testing indoors.
(the AC powered house/garage lights need to be turned off or you'll get screwy readings...)

RE: Tachometer Problems
 

CP and Proptop,

Thank you bothvery much. Now that I think of it, the RPM's seemed to become more and more close to being somewhat believable the closer I got to having the sun at my back (I have been outside both times Ihave tested). Maybe this had something to do with it...maybe not, but I will have to try again soon.

Thanks again,
KP

RE: Tachometer Problems
 

What type of prop are you using? Sometimes these photo tachs are not especially sensitive to plain black coloured props (or dark coloured ones generally) I have seen some people put a dab of paint on each blade (it has to be both blades-for obvious reasons!) to improve the contrast.
I have a couple of (as yet unrun) Fuji 099s so I'd be interested to hear what rpms you're getting on a particular prop and fuel. Also have a 15 and a 19. Once upon a time Fujis were a bit on the cheap and nasty side-have you seen what MECOA are charging for Fujis these days.

RE: Tachometer Problems
 

Hi FFkiwi,

I have aBlack MAS prop. Ineed to add stripes justfora little added safety anyway. Very good idea, though. With all of these suggestions, something has to work! Thanks for sharing.

I'm runningSig Champion 25% with a7x6. I know that a 7x6 is overproping it, but Ididn't have a smaller prop at that point in time. I ran it more on the rich side, anyway, just tobe safe, though.

As for the value of a Fuji .099, Idon'tthink that they are anything special, but mine is living proof that, if takingcare of properly,even an overproped enginewill never wear down. And for a $20, thisengine is a nice one. If only I had decidedtopickup theNIB Fuji .099 that I saw at a yard sale two days ago...http://www.rcuniverse.com/forum/js/f.../sad_smile.gif

I will have to remember to post results for you.

KP

P.S.Man,am I happyto know that thereare others out there with this engine. I have not been able to find any information on this engine so I have been goingwith what Iknow.

RE: Tachometer Problems
 

Check your tachometer with a incandescent light bulb or fluorescent light, it should read 3600, and a CRT television should read 1800.