Measurement of CofG

On Jan 15, 8:57*am, "Dan Marotta" wrote:

Really, how accurately can you measure 2.9 inches, mark it, and cut it?

I think that just on the far side of 2-7/8" would do just fine.

...it looks like 100:2.9 is an angle of 1.6618 degrees. *Will a
digital level get that accuracy? Is that accuracy really necessary?

Most digital levels will offer repeatable measurements to 0.1 degrees,
and I think that that is close enough. In this case I'd feel fine
about a reading of 1.7 degrees. For my fuselage, the exact tailboom
slope is 1.213 degrees, but 1.2 or even 1-1/4 degrees would be fine.

What's the good of a parallel surface if it's not accessible? *Why not make,
say, the arm rest parallel to the longitudinal axis? *Then you could simply
place a carpenter's level on the arm rest and, voila!

Thanks, the armrest trick is a good idea, I might adopt that; it would
be useful for people who have digital levels that beep when they're
actually level.

Thanks again, Bob K.

I like the idea of a "beeping" level which would allow a single person to
complete the operation. And I *really* like the design of Wayne's "wedge".

Bob, thanks for stating what I've always felt, i.e., the TLAR method is good
enough (2-7/8"). I was (wrongly) getting the impression that people were
stuck on precision which I couldn't attain. It would seem pointless to
measure the angle to a gnat's ass and then fly with boots and a heavy jacket
one day and shorts and sneakers the next.

One more time - Wayne, I LIKE the design of your wedge. I think I'll build
one. And ask the manufacturer why they don't include at least a drawing for
a device to level the fuselage.


"Bob Kuykendall" wrote in message
...
On Jan 15, 8:57 am, "Dan Marotta" wrote:

Really, how accurately can you measure 2.9 inches, mark it, and cut it?

I think that just on the far side of 2-7/8" would do just fine.

...it looks like 100:2.9 is an angle of 1.6618 degrees. Will a
digital level get that accuracy? Is that accuracy really necessary?

Most digital levels will offer repeatable measurements to 0.1 degrees,
and I think that that is close enough. In this case I'd feel fine
about a reading of 1.7 degrees. For my fuselage, the exact tailboom
slope is 1.213 degrees, but 1.2 or even 1-1/4 degrees would be fine.

What's the good of a parallel surface if it's not accessible? Why not
make,
say, the arm rest parallel to the longitudinal axis? Then you could simply
place a carpenter's level on the arm rest and, voila!

Thanks, the armrest trick is a good idea, I might adopt that; it would
be useful for people who have digital levels that beep when they're
actually level.

Thanks again, Bob K.

On Jan 16, 8:13*am, "Dan Marotta" wrote:
I like the idea of a "beeping" level which would allow a single person to
complete the operation. *And I *really* like the design of Wayne's "wedge".

Bob, thanks for stating what I've always felt, i.e., the TLAR method is good
enough (2-7/8"). *I was (wrongly) getting the impression that people were
stuck on precision which I couldn't attain. *It would seem pointless to
measure the angle to a gnat's ass and then fly with boots and a heavy jacket
one day and shorts and sneakers the next.

One more time - Wayne, I LIKE the design of your wedge. *I think I'll build
one. *And ask the manufacturer why they don't include at least a drawing for
a device to level the fuselage.

"Bob Kuykendall" wrote in message

...
On Jan 15, 8:57 am, "Dan Marotta" wrote:

Really, how accurately can you measure 2.9 inches, mark it, and cut it?

I think that just on the far side of 2-7/8" would do just fine.

...it looks like 100:2.9 is an angle of 1.6618 degrees. Will a
digital level get that accuracy? *Is that accuracy really necessary?

Most digital levels will offer repeatable measurements to 0.1 degrees,
and I think that that is close enough. In this case I'd feel fine
about a reading of 1.7 degrees. For my fuselage, the exact tailboom
slope is 1.213 degrees, but 1.2 or even 1-1/4 degrees would be fine.

What's the good of a parallel surface if it's not accessible? Why not
make,
say, the arm rest parallel to the longitudinal axis? Then you could simply
place a carpenter's level on the arm rest and, voila!

Thanks, the armrest trick is a good idea, I might adopt that; it would
be useful for people who have digital levels that beep when they're
actually level.

Thanks again, Bob K.

when we did the W & B for my Tetra we used a 24" level and a 1/2" tall
socket, with the level located as required by Bob it was easy to set
everything up on scales. I had my engineer friend do the
math............empty weight came out at 479 pounds!

Brad