Hi
Post 13 has a picture showing the area under the wing where the elevator and rudder servos have been placed. It is just a ply plate epoxied in place.

Hi

having finished the full house version I decided to use my Houston Hawk wings to make a RES version
I had an old detachable centre section lying about so I redrilled it to fit the pod and fitted my Hawk wings.
The area is nearly the same as the Gracia wing so I wont have to build a new tail.
All I need now is some decent weather to test it.

Hi
Managed to get out flying today.
The conditions were damp and turbulent, but we went ahead and test flew Buzrd number 2 as well as my original one.
Wind started out at circa 5/7 mph but by the end it was blowing 15 steady and gusting much higher at ground level ,higher up it was obviously much windier. We were guessing around 20/25mph
They both flew very well and handled the conditions much better than we had a right to expect from a lightweight
No. 2 flies almost identically to the first one just some minor CG issues to measure and resolve.
One odd point was that my lighter 1550gram model was penetrating better than Georges 1700 gram one. (Heavier motor and battery) which also created the CG issue.
All we need now is for the other models in construction to be finished and for a competition in order to have the "acid test".

Hi Gents,
Your models look lovely, I'm very impressed!! Good luck with the contests.
Happy flying.
Chris.

Very interesting thread. Looks as if Ian has taken the time to come up with something rather interesting that is not just a "ready to fly out of the box" F5J model, but he has taken the time to come up with an assembly of the best and lightest components.
The light weight is very important as very often there are very light air or even sink conditions in this area which means that models can be on the ground in less than 2 mins even from a 200m launch. Providing that the handling is good, there is a much better chance of staying up with a light weight model. Ballast can always be added for the more robust conditions!
Speaking of which, I wonder a bit about the power levels being used. Ok it gets to altitude in around 20-25 secs which is reasonable, but it would be better to have something in reserve especially for windy conditions even if this means slightly more weight.

hi
RBF

At the outset I knew that I was trying to build at the light end and would sacrifice windy weather performance, the main reason I ignored it was that I have a Super Starlight -E sitting there which does the job admirably in the wind but it does lose out to Avas and Pulsars in the really light stuff or in damp air with no lift about. Boy have we experienced that this year!

The Buzrd has exceeded all my initial expectations in terms of its performance envelope , particularly in small light lift patches that require tight turns; additionally I can add up to 700 grams of ballast easily
Ballast rod in the wing + 550 or +400 or + 200 or + 100
Heavier battery + 150

I also can prop it up a bit quite comfortably but only if I fit the higher capacity Lipo.
So far I have only gone as far as +250 grams but it flew easily in 15mph wind at ground level and it was obviously blowing 20+ upstairs.
However in competition terms if it gets say 12/13 + I would probably change to my Starlight.

Hi
After a prolonged spell of poor weather, the first chance to try out the Buzrds in a competition was our National Championship. great place to try out an untested model.
Well I am delighted with the result we took two Buzrd's to the event and placed 3rd and 5th.
In fact I feel that I let the model down by only coming third but I was beaten by two better fliers who had come over from France for the event.
However, what was the opposition, Maxa , Pike Perfect, Pulsar, Hyper Ava, Supra.
The design has certainly fulfilled the original brief and then some, it can take on the best and is much much cheaper.
Try one you won't regret it.
Ian

Hello Ian,
I have followed this thread with interest .You have certainly acheived your initial objectives and have finished up with a lightweight,competitive model which doesn't cost an arm and a leg.
I am thinking of adopting some of the principles and components you have used to make a fuselage for my Pike Perfect wings; the idea being to achieve a weight significantly below that of of my current model,which is well over 2Kg.
To see if this is feasible I wonder if you could provide a bit more detail on the weight breakdown of your model.In particular, do you have the weight of the fuselage(complete with all necessary kit apart from the wings) and the weight of the tailset.
As I know the weight of my Pike wings I should be able to get a good idea of what total weight is possible.

Thanks in advance,

Spencer.

Hi
The weight of the fuselage and complete tail group and without battery is 550 grams
tail plane 35 grams and Fin and rudder were15grams assorted components brought the lot up another 5. So fus ex tailplane ex battery 495 grams.
I hope that this helps.

I just re read some of this and realised I had missed a bit of info.

The Mega16/15/3 with Reisenaeur 5:1 gearbox, Turnigy 1400 lipo. 40c. Delivers 408 watts, the Buzrd hits 200 metres in 18 /20 seconds. more than adequate to push way out on a lift hunt .


if any of you guys reading this have any ideas of your own please chime in, we all want to know, it might help our next models along.
Ian

Thanks Ian, that is very useful indeed.

After making allowances for a few small differences in the weights of some of my components it looks as though,by adopting your approach, I could finish up with a model with a total weight somewhat under 1800gms.This is a reduction of around 300gms compared to my current set-up and would result in a wing loading around 7.4 oz/ft2-Pretty good for an all moulded 3.7m wing.I am minded to follow you and have a go.

It also struck me that what you did may be a good way of using a surplus F3J wing as the basis of producing a competitive ALES model at a reasonable cost.

Just one more thing if you don't mind. Can you provide details of the tailset pushrod arrangements.I don't seem to be able to see what you did from the photos.

Spencer.

Hi
I have taken some photos of the tail end. I know I should support the pushrod tube to the rudder but at present it is very stiff and there is no play in the rudder. The tube is glued to the boom every few inches along its length.

I have already started on a project to use the fuselage and tailgroup set up to take an old F3J wing by using an adaptor plate fitted to the current hold down former.

However I do want the tail end as light as possible but strong, so I am teaching myself how to make a carbon cap-stripped tail with carbon t.e. similar to the AVA etc.
If I can build lighter than at present it will be a bonus that pays off in the handling characteristics of the model. Light tail allows lighter nose and reduces the push effect of weight at the extremities, the Bolas effect.
Have any of you experience of this ?

Hi
I have now drawn a new tail group for use with an Explorer wing.
Carbon spar and t.e. and hopefully carbon caps if the pony express ever deliver the materials.
I am drawing up a tail group for use with my old heavy Aspire wing and will build it when I have the material to hand.
The fuselage will be the same as the Buzrd's set up and I will have to revise the power train set up.
Any ideas for a 3.7m model weighing about 2.6kgs.
Ian

Hi
At last I have started on the parts to go with my superannuated F3J wing (1.6 kg)
I attach a photo of the new tailplane and I am starting on the Fin / rudder now.
This is the first time I have tried to build with carbon so it is a learning experience and I will probably oversize everything !
The t/p weighs 40 grams as seen.
The blue pod is from Kristoffair and will be used with a Super AVA boom and V-mount.
2 MKS 6100 servos will go in the fus for rudder and elevator. The wing already has 4 Futaba 3150s

Ian

Hello from RCbobcat55@yahoo.com I must say you have some very impressive looking models. I am by chance working on a prototype 96" span electric sailplane which may be competetive in this event and certainly will be cheaper to obtain. It has a 6 panel foam core balsa sheeted wing (or you can vac bag it if you want) featuring 4 different Drela AG airfoils from root to tip. A pod and boom fuselage (custom laid up glass one is in the works, and a V tail to keep it simple. Also flaps in the center sections. Two piece wing which slides onto rods in the fuselage. Built-up sheeted V tail. I have not worked out the best power system for it yet but I want to keep things reasonable so most people can afford it and also be competetive. So far I have the wing, tail, and prototype pod built and may build another pod more suited to electric power instead of just cutting the nose off. I have access to a laser cutter and also produce foam cores for a number of small kit manufacturers as well as one-off designers. I can clean up my 3-view sketches and e-mail copies of them to anyone who wants to see what it looks like. Let me know if you have any insterest. Thanks Bob M...

Well I have started on the fin and rudder, the photo shows 6 strips of thin balsa which have been steamed and then gripped at one end and bent round a former and allowed to dry in that position. Note that as they are only gripped at one end there is some slippage in the strips as the conform to the curve this helps to ease the curve.
I will glue this up bent to shape for the leading edge of the rudder, not only is it an easy way to get a nice curve it lends strength to the structure.

I will power this model with a Mega 16/25/3, 4.2 Kontronic gearbox, 1300 4s 45c lipo and probably a 17 x 11 propellor. That should prove adequate to reach 200m in around 24 seconds.

As an aside I tried a slower climb with my Buzrd reaching height only just within the time limit. I did not like it. I prefer the slightly faster climb rate as when the motor cuts I have a faster flying model which allows me to manage the transition to gliding better. Less chance of stalling it off the top.