Further progress, too hot to keep painting the house so I have grabbed a couple of hours to do something about the perceived aileron problem.

Hi
Some further progress,
The photos show the parts screwed together or held in place with paper tape.
Weight is 1275 grams
excluding rx,esc and battery and with my heavier motor option.
This exercise was to establish the weight so far, and give me an idea of the cg situation.
Based on today's work the CG will be no problem with the heavier motor option Mega 16/25/3 and Maxon 4.4 g/box, in fact I will have to cut back the nose.
With 1800 3s Lipo . castle 80 esc and a Rx weighing 25gms that is 225 gms in total Final estimated weight is circa 1550 Grams . well within my design parameter of 1600 grams.
However I have just fallen heir to a Mega 16/15/3 weighing 78 grams, a Reisenaeur Micro Edition gearbox is 18 grams a potential saving of 75/80 grams.
A 40 amp esc and a 1300 lipo would save another 50 grams.
This means that the all up weight could be reduced to circa 1425 grams that's about 50/51 ounces for you guys using ounces.

I should manage to finish it off this week and hopefully test fly it next weekend.

Ian

Very nice. I am following with interest...

Dude,

If you really want to shave out some weight with a wonderful motor/Gearbox stup I would recommend this one http://www.reisenauer.de/artikeldetails.php5?aid=1344

It's not cheap but I guarantee it will put a big smile in your face!

If you're more agressive (and have more $$$) you can go for this one http://www.reisenauer.de/artikeldetails.php5?aid=1344

It's my dream...

By the way, congrats on your project!

Cheers!

André

Hi Andre

yes I have looked at Herr Reisenaeur's offerings with great interest.
There is a 5:1 gearbox on its way, so much for my budget !

I will fit it to my Mega 16/15/3 it should give me similar power to either a Scorpion or Hyperion Reisenaeur set up. Only time will tell.

My current worry is that I have gone too light for our weather conditions.
We are in a West maritime climate zone and fly near the sea coast, this means weather changes are frequent and rapid. No one would risk a 5 second motor run to 60 metres here. In comps we all go to the max height allowed and still get shot down in 3/4 minutes on some occasions. It makes the landing element of the task vital.

I am now looking at safe ballasting methods and ways of increasing weight/wing loading for windier conditions, and of course may have to step up the power to cope with the potentially increased weight of the model.
However I will have to wait to see just how quick to 200 metres it is and work from there. I am anticipating about 300 watts on a small battery and maybe 350 if I step on it a bit prop wise.
This is all after the test flying so I had better get it finished.

This week I had the pleasure of meeting Chris, the owner/operator of Kristoffair, a very nice fellow.
I look forward to building with the pod I purchased from him, and will report the results here in a few weeks when work is complete.

Iain

Ian,
Your model looks fantastic. I get a real buzz when I see the finished models good luck with the test flights.

Rev. Ian,
Nice to have met you, I enjoyed our chat. I’m looking forward to seeing your model progress happy building!!

Thanks for your comments Gents,
Chris.
www.kristoffair.co.uk

Hi
Having waited all week to test fly the model ,no opportunity to fly on Saturday and Sunday has been 15 mph + winds. Not really suitable for test flying a light weight.
Instead I set up my lighter drive set up to check CG etc.
It has come out at 1455 grams. Most acceptable.

My gearbox has not yet arrived from Germany. I know Herr Reisenaeur posted it because I have the DHL tracking number from last week. Lets hope it comes on Monday and I can get it fitted.
Test flying Tuesday I hope.

Hi
They say the proof of the pudding is in the eating.
I attach photos of Buzrd in the air and the altimeter log of the third flight.The first two were test hops to about 30/40 m. to check/change settings and the third was a full blown run to 200 m. Note the crow down at the end from about 750 feet .
The model set in heavy trim at 1740 grams.
The motor was Mega 16/25/3, 4.4:1 Maxon gearbox and Aero Naut 15 x 10 propellor.
4S Turnigy 1.6 Lipo
It reached 200 meters in 25 seconds on what I call a mild set up. About 350 watts

Now flight performance.
The c.g. was way too far forward at 65mm behind the l.e. on initial flight. It lumbered around rather than flying smoothly.

Some hurried battery shifting took it back to 75mm back and you will see the attached flight log shows reasonable performance. My mate's Super Ava had just been shot down in 5 minutes. It could manage the light lift but could not come back against the turbulent air.
This is why I built this thing. I have had too many days with my Super Ava when you got it away no problem but coming back was always going to be an issue.
I am not knocking the Super Ava ,it has served me well but it is the old story of "horses for courses".

I will reset everything for my light set up and try and get better photos next time out.

Hi
A series of mishaps this weekend, firstly my lightweight set up could not be used as the esc packed in. I refitted the heavier motor set up which needs an onboard rx pack and 4s lipo total weight circa 1.7kg
The weather caused a bit of a problem for test flying low cloud base to about 40/50 metres and cold and damp with it.
I carried out a few short motor runs to the edge of the cloud and checked out throws,various mixers and set the amount of down elevator needed for crow..
I am still not altogether happy with the aileron differential set up I have not been using much for some time now but this one seems to need about 2 or 3:1.

Now the actual flight performance. it seems very stable ,responds well to control inputs, turns amazing tightly and quite flat. Unfortunately there was no one else flying a thermal soarer for me to compare with.

Next weather window is on Wednesday.!

Ian

Hi

I Managed to go flying today with a bunch of guys who are the usual opposition in our competitions.
Is it up to the mark ?
I think so, like all models this was a compromise between out and out light weight for a low sink rate and the ability to cover the sky quickly, I opted for the ability to move around more than, say, an Ava, but less than the average moulded model.

I consider that this has been accomplished.
The flight characteristic are fairly docile.
It requires very little rudder input in turns and after the initial aileron and rudder inputs to start a turn you can neutralise the controls and just use the elevator to either keep it tight or open up the turn.
It needed the 2:1 aileron differential to counter adverse yaw.

To turn to the power side.
Mega 16/15/3 Reisenaeur Gearbox 5:1 15 x 8 prop Turnigy nano tech 3s 1300 mah Lipo

On this set up it took 28/29 seconds to reach 200m on a day with little wind only a breeze. On the other hand lots of climb outs from the battery pack.

I changed to a 15 x 10 prop and the Buzrd reached height in 20 seconds and the pack was flattened in about 3 climbs. There is obviously a big jump in current draw with the pitch increase.
I will either have to up the lipo size or find a 15 x 9 to try out.

Forgot photos
Ian

Hi Ian
Very impressed with the build thread,a few questions
What is the wing section of the chosen wing assy and what type of spar?
where are the servos located(or did I miss that bit)
How did you make provision for adding ballast?
Cheers B

Hi
the wing is from Top model and is a Gracia wing, MH32 section
It has a 12mm i.d .carbon spar right on the CG a rod down the middle is the ballast
The weight ready to fly is 1515 gms
Look at the wings and where you see a solid plate between ribs that is 3mm ply mounting for servos. The pictures should show the fuselage mount again just a ply plate

Sorry Ian
I meant the rudder and elevator servo mount
Cheers B