aeajr

My Feedback: (2)

Any advice on a low cost device that will let me measure the altitude of my plane, either overhead using some sort of a range finder, or via some kind of a transmitter device?

I am aware of the LoLo, for about $115, but that is an "after the fact" recording device. I am looking for something that will give an altitude at this moment as I fly overhead.

I am just curious as to how high I am flying. Any suggestions would be appreciated.

FHHuber

You can make a simple rangefinder for under $2. You set the plane at a measured distance from yourself and mark what the wingspan looks like on a card, repeat for several distances. (the card needs to be held a constant distance from your eyes when making the marks)

Then you cut a series of "calibrated" notches in the card forming a V :

|__ __| =150 ft
|__ __| =300 ft
|__| = 450 ft

The card gets mounted to a stick which aids in holding the card at the correct distance.

You need a second person to do the range measurement... its VERY hard to do the measurement and fly the plane at the same time.


You can convert the range to an altitude by trigonometry... just measure the angle from vertical of the stick when taking the distance reading. You've got the length of the hypotenuse. [img]i/expressions/face-icon-small-wink.gif[/img]

FHHuber

The system reformatted my spacing on the notch formation.... [img]i/expressions/face-icon-small-sad.gif[/img]

I can scan in an article from a 1930's magazine on how to make the mesuring device. (Still commonly used by FF modelers.)

aeajr

My Feedback: (2)

This is an outstanding idea. I love it! If you can scan the article I would love to read it just for interest, but the method is clear.

Bill L

FRED and ED, The card idea is really neat. I too wonder how high I'm flying my XL. I figure that if I can glance at my watch to estimate time remaining on the battery, I could look at a card, let's say mounted on my transmitter at arm, or neck-strap length, for consistancy.[img]i/expressions/face-icon-small-smile.gif[/img]
ED, I've checked into altimeters, too, but only found "after-the-fact" instruments, and "AFTER MY BUCK$" pricing[img]i/expressions/face-icon-small-happy.gif[/img]
KEEP 'EM HIGH, BUT IN SIGHT![img]i/expressions/face-icon-small-shocked.gif[/img]

aeajr

My Feedback: (2)

I keep a flexible metal ruler in my field box, so I took a marker and a 50' tape and made a 50, 100, 150 and 200' mark on my ruler. A quick glance at the bird and I have a quick guestimate which is all I wanted. + or - 20% is close enough.

Anything over 200' at this point is just "high up there"

DEW

If you could scan a copy of the 30's article it would be great!

Thanks DEW