Lamaroo COG/thrustline tests.

Murray Barker · 21-04-2007, 07:26 PM

Here are the first lot of photo's from the COG/thrustline test done at the last Nats.The photo's were taken by Graeme Monro and lines drawn by Tim McClure.
First picture is "Hunchback" 4.5 Inches below COG. (LTL)
Second is Magni 14 Inches above COG. (HTL)

Murray Barker · 21-04-2007, 07:29 PM

Third, Firebird 6 Inches above COG. (HTL)

Birdy2 · 21-04-2007, 07:43 PM

Is that with or without the tail Muzz.

Flame chook a 6" high TL?

, its gota be riged, surely.

I thought it was sposed to be LTL, or at least CLT. :

Murray Barker · 21-04-2007, 08:02 PM

Very fookin' funny David, Hunchback was "hung" with the tail on.

Yes FB is HTL,but I didnt have anything to do with the tests so dont blame me. The other gyros done will be posted in due course.

russ · 21-04-2007, 08:02 PM

Hey muzo..........you seen waddles Raftorr, what do you rekin these will be ????????

Murray Barker · 21-04-2007, 08:23 PM

Hard to tell Russ without the double hang test but I would say the thrustline is a good 6 Inches LOWER than Firebird but with a 76 Inch prop the cabin is more than 6 Inches HIGHER than Firebird. Basically all this means is Paul only has to raise his cabin 6inches to be CLT and it still wont be as high as a Raftorr for ease of entry.....clear as mud ???

Aussie_Paul · 21-04-2007, 08:44 PM

Ah come on!!! 6" what a hoot. The pic is not square on and the line was being held dangling from a stick.

Common sense says that Firebird is very very different to a Raf and the Raf has a 10.5" offset.

Firebird is quite a bit different to Hybrid and it was only 2" at MTOW.

But if that is what you want to believe it don't worry me as I know how it flys.

When I get time I will accurately conduct the CoM tests, as I have in the past, with a tripod etc for the pics.

Due to being slightly LTL I have taken 3" out of the mast. Since Lameroo I have flown 30' RAFs, two designs of Robs 30' and the last few days the 29'. This week will be the AK 33'.

Today I flew with stabs removed, and the application of cruise power to wot had the nose begin to lower gently, about the same as the nose rose during the first tests several weeks ago.

Next I fitted the stabs back on and was slowly increasing the negative AoA of the stabs each flight. Dark beat me before I perfected the stab pitch but I was quite happy with the stability results at that time.

There is now around 35 hours on the Hobbs so I have been having some fun as well as doing the spanner work.

Aussie Paul.

ps. Maybe this pic should have been used as the 2nd pic

It aint always as it seems.

Aussie_Paul · 21-04-2007, 08:47 PM

My hub bar got ruined by the lifting device at Lameroo. Thgose who had their machines lifted with the device should check their hub bar for indentations and/or marks.

I will find the pics and add them to this post shortly.

Aussie Paul.

Murray Barker · 21-04-2007, 08:53 PM

Paul, the yellow line is the one to look at, dont look at the line the old fella with the fishing pole has!.The yellow line is parallel to the white line and exactly thru the teeter bolt.The gyro is square on. Your gyro is 4 inches better than a Raf and 8 inches better than a Magni so dont take it to bad. We are not all out to get you or prove anything.

Aussie_Paul · 21-04-2007, 09:09 PM

I can assue everyone that Firebird is not 6" HTL. Just conducting the stepped keel mods on a RAF brings the offset down to 7", and this has been verified by the mathematicians.

Step back and look at the forest and the trees.

Murray said, "We are not all out to get you or prove anything."

That is immaterial Murray. Anybody who believes that Firebird is 6" HTL is just plain wrong.

Aussie Paul.