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Nov 24, 2019, 04:33 PM
Foam is where the heart is
brett.c's Avatar
Thread OP
Quote:
Originally Posted by springer
Two good ones! One advantage we have as modelers, the "gummint" won't come for us if we put somebody elses ID on our planes!
Shhh, don't give then any ideas It won't be long before in the nanny state of Oz we have to register our "drones".

I added a stripe along the h-stab and it now looks about right. I'm also starting to piece it all together. Flying weight will be 1350g, which will give it a wing loading of 52g/cm2 or 17 of those other things. A WCL of 10.2 puts it in the aerobatic sports category.

Most importantly, she is still a tad nose heavy, so I may avoid the dreaded lead.
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Nov 24, 2019, 06:42 PM
Build straight - Fly twisty
Whiskers's Avatar
Good work.
The clear coat may be enough to get the CG perfect with zero "dreaded lead."
Nov 26, 2019, 05:21 AM
Blue Remembered Hills
ShropshireLad's Avatar
Looking forward to the maiden flight report soon Brett, what's the expected timeframe? Stunning work as usual btw!!
Nov 26, 2019, 06:35 PM
Foam is where the heart is
brett.c's Avatar
Thread OP
Hi Shroppy.
I'm in the process of covering it 2 coats of clear and then assembling everything.
Hopefully I will maiden it next week at one of the old men's mid week meets.
Nov 29, 2019, 02:21 AM
Foam is where the heart is
brett.c's Avatar
Thread OP
Ok, she's about ready

A few d'oh! moments during assembly.
1/ Too much flex between the elevators. I used 2mm wire for this but it wasn't stiff enough. Fix was to add a cf rod doubler fixed with cotton thread soaked in CA. Problem was that the hinges were all glued in . I use clear gorilla glue for hinges (much better than CA) so there was some damage getting it all apart. Luckily the paper covering just folded back in place to you hardly notice.
2/ With full down elevator and then fully right rudder the elevator was lamming under the rudder control horn. Not a likely scenario when flying but best not temp fate. Fix was a new control horn made from aluminium angle and made such that the horn sat a little lower.
3/ She's a bit nose tippy on her landing legs. I mounted the legs a little close to the CG line . Fix was to dremel out the mounts so the the retracts could be canted forward a little more. Not perfect so I may have to add some sort of nose skid for the inevitable tail bow on landing.

Flying weight is 1380 grams which gives a wing loading of 53g/dm2 or 17.3oz/ft2. With a CWL of 10.3 I'm pretty happy with that.

The CG worked out fine with no dreaded lead. In fact, I originally measured the CG off the plan incorrectly at 68mm when in fact it was 85mm. A cg calculator confirmed this giving a CG between 80 and 95mm depending on how tail happy you like it. So she's in fact a little nose heavy ATM.
Nov 29, 2019, 03:31 AM
2 metre rule applies!
DRAMJET's Avatar
Looks great, Brett.
Nose bows..... it will just fit in with the rest of our landings!
Nov 29, 2019, 08:15 AM
Build straight - Fly twisty
Whiskers's Avatar
Splendid!
When you said the black trim line on the wing was on the CG, I thought it looked horribly forward.
All good now...
Nov 30, 2019, 05:09 PM
Registered User
Hi Brett, nice build.
Fun to se a foambuild with high level of finnish
I hope maiden is succesfull now?

// Mats W
Dec 02, 2019, 06:16 PM
Registered User
Hey Alfa man

Good to see you're still building and flying mate. Long time no talk.

Mate i've gotta say that is a cracking build that you've done. I've seriously gotta stop building big complex models and do stuff like this that doesn't take years to build.

I can't wait to hear how the maiden goes.

Cheers Glenn.

P.S. Guess who else flies these days. Goold old Mr. Pink himself. Andrew Komnacki haha.
Dec 02, 2019, 08:32 PM
Foam is where the heart is
brett.c's Avatar
Thread OP
Hiya Noisey

"Alfa man" sheesh! bloke takes one wrong turn in life and he can never live it down

Yes, it's been a long time mate. I keep well away from the hotrod scene these days. Even though I now consider myself fully cured I don't want to get reinfected.
Not now that I'm on the industrial scrap heap and can't afford expensive hobbies.

Andrew, I knew he was a closet nerd. It was that pink coupe that gave it away, it was like a cry for help. Say gidday for me.

Took Elgringo to the field today but it was way too windy, and too smokey for a maiden.
Dec 03, 2019, 12:42 AM
Build straight - Fly twisty
Whiskers's Avatar
Quote:
Originally Posted by brett.c
<snip>

Took Elgringo to the field today but it was way too windy, and too smokey for a maiden.
You are very wise to wait for suitable conditions before doing test flights.
It's just plain common sense to do so, but as Voltaire said."“Common sense is not so common.”
Dec 05, 2019, 01:37 AM
Foam is where the heart is
brett.c's Avatar
Thread OP
Quote:
Originally Posted by Whiskers
You are very wise to wait for suitable conditions before doing test flights.
It's just plain common sense to do so, but as Voltaire said."“Common sense is not so common.”
Yes, still waiting for the right conditions. If it ain't too windy you're choking on smoke.

Ah, Voltaire, every cynics go to guy.
Dec 05, 2019, 11:21 PM
Build straight - Fly twisty
Whiskers's Avatar
We don't want to see El Gringo in a sky like that.
He deserves much better...
Dec 08, 2019, 04:19 PM
Registered User
It's no better down here in Canberra. This was out my front door yesterday afternoon.
Dec 10, 2019, 02:26 AM
Foam is where the heart is
brett.c's Avatar
Thread OP
Ok, filthy conditions again today, however winds were light enough for me to attempt the maiden.
Just a short 3 min test flight to sort the trim and check the cg.
She likes to chew grass on take off so I had to give it plenty of up elevator until the tail lifted, After that the takeoff was quite easy.
Needed a bit of down trim but was rolling to the left a fair bit, so need a lot of right trim.
Once trimmed she flew quite nicely. Has a propensity to tuck under on slow bank turns. I put that down to the cg being a bit too far forward for the maiden.
It also felt a bit "heavy" on the elevator which may also be due to the forward cg.
She likes to fly fast, which is ok because so do I
Glide slope is quite good and she took a few go arounds before I could set up a decent approach.
Once landed she took the customary warbird bow, as was expected.

I will move the cg further back and try again. I also need to check out what is going in with the aileron trim. She is balanced across the wingspan so it may just be aerodynamic (ie slight wing twist). If that's the case I will just live with it.


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