Emoyeni #3 takes to the Sky.

After a busy few weeks before the Nats , I eventually got some time in to finish my 3.4meter Emoyeni.

(Glen from Durban will be glad to hear this, as I can move on to the next project that involves making a mold), but yesterday (Sunday 18 May) I maiden the Emoyeni , and it is just amazing how easy and true this composite gliders flies.

Other than a ground range problem (resolved by removing the Rx aerial to the outside of the fuse), 15g nose weight and some adjustment to the elevator compensation on the full crow -setting , every flight that I few went well. I have to say that I still have to learn a lot about and getting use to the handling of the glider and lots of fiddling with trim, tow hook and CG settings will follow.

However first prize is to go home after your maiden flights with the plane still in one piece.

Later on Evan came around with his new 3.7 meter Emoyeni and we flew a few flights together.

For our overseas visitors the name Emoyeni, translated from Zulu to English means “Upon the wind”.
The name of the Glider was inspired by the Black Eagles which visit our club from time to time. They nest on the nearby ridge and can often be seen thermalling overhead. The females name is Emoyeni. Check them out at this link to the Black Eagle Project at Roodekrans

The real Emoyeni


EMOYENI"UPON THE WIND"The grand old lady is probably 35-40 years old and is loved by many who have followed her life cycles with passionate interest.The first sightings of Emoyeni were in the early 1970's with her first mate, unfortunately we do not know anything about him. Quatele was her second mate and she scoured the ridges searching for him when he disappeared in 1998. Patiently taught her third mate Thulane everything she knows, tolerating his initial shortcomings, but now appreciating his newfound expertise. Many a lesson could be learn't from this wondrous lady.
Click on the Lable below to see previous posting on the Emoyeni

New Emoyeni takes to the Sky

Evan's new 3,7 Takes to the air on its maiden flight.

The Berg field yesterday bussed with activity as pilots for the upcoming nats this weekend did their practice roundup. Many new planes were observed including our new local challenger Evan's 3.7 Meter Emoyeni.
The first flights even in strong wind look very promising. The Berg Team will be represented by Evan, Piet and Derek

Emoyeni gets purple wingtips

Top View















Bottom View

Shocking! Hey!
But I should be able to see it now!
I hope!

Emoyeni takes to the air

The Emoyeni maiden flight - Sunday 18th March.

After months of on and off building on the Emoyeni, while preparing for the Shongololo building group, the project was finally completed with it's maiden flight this past weekend.

The plane is 3,4 meter span and weighs in at 2650grams. With a wing area of 65sqdm it has a wing-loading of 40 gr/sqdm. A bit heavy you might think, but first flights proved that the design can carry the weight very easily.

When the project was stated it was decided to build the wings with NO spars , but instead, to use unidirectional carbon skins. The top surface has a total of 5 layers of UD carbon across the middle 400mm then getting progressively less until just one layer at the tip. The bottom surface has 3 in the middle to 1 at the tip. This method is not the lightest of constructions, but it's very strong, quick and easy to Bag and not very expensive. When I realised that the prototype was going to be a bit on the heavy side I chose the SD7037 section because of it's ability to carry weight.

It is a three piece wing with 2 x 10mm solid carbon joiners at each joint. The fuselage is moulded fiberglass and the tail is an all flying inverted "T" design.

The prototype flew with a Shongololo stabiliser, because the Emoyeni moulds are still not completed. This also contributed to the back end being a bit heavier than desired, causing more lead to be added to the nose, upping the overall weight somewhat.

The first flight was really fantastic. Straight into a thermal and it was soon trimmed out and going up like a homesick Angle. One problem was that I had sprayed the underside of the wingtips white (Oops!) and they soon disappeared form sight and all I could see was the black centre 1400mm. It was like flying a HLG in a monster thermal and rapidly loosing sight of the plane.

So Crow break was deployed and it soon got back down to a more comfortable height where I could see it properly. Overall a very successful maiden outing and I was impressed with the tight thermal turns it can make and the responsiveness of the whole package.

I'm a very "happy chappy" as they say!

The first priority is to add some colour to the underside wingtips and the next is to start on number two. Watch this space!

Cheers

Evan

EMOYENE, AND STILLETO MORE BUILDING

The progress of the two new designs at the B.E.R.G. club is slowish but steady ,hereunder some more building methods.

After the recent photos posted I promised some photos of the tailplane and wing layups,

EMOYENE being vacumn bagged , breather cloth, white lays over the mylar skins in the bag.

Here the mylar sheets are being removed after vacumn bagging.

the EMOYENE is vacumn bagged glass and uni-directional carboncloth over pink foam, this layup is interesting as there is no spar and the rigidity comes from the skins.

EMOYENE mock up reveals a super looking thermal duration sailplane, sleek and elegant.

STILLETO tailplane.
Good preparation is everything, here you see ,yellow sprayed moulds, light weight glass cloth for the first layer always cut at 45 degress so the glass strands are diagonally across the wing ,this helps resist torsional twisting.The sandwich material (not shown) is 8gr per sheet .8mm balsa and finally the uni-directional cloth pre cut to the tailplane shape.

Tailplane joiners etc get bonded in at the correct places before joining the two halves.

After joining in the moulds with a bead of cotton flocks/micro balloons and resin to a runny paste,all is cured then the tailplane is released from the moulds and just needs some finishing off.

The STILLETO has a hollow moulded wing with a glass herex sandwich and also a layer of uni-directional carbon as well as conventional carbon tow spars, it feels very strong, but then again its a big wing at 3.7 mtr and high aspect ratio, both gliders have a root chord of 240 mm.

Here the wing centre panel is vacumn bagged in the mould , the dowel sticks wrapped with a breather fabric lie between the moulds and allow even vacumn throughout the sealed bag.

Check out more of the the latest photos soon, and please if you have any questions post them in the comment box at the end.

THE NEW GLIDERS PROGRESS

By now I have had some feed back from interested parties about the two gliders currently under development by B.E.R.G. members, our goal was to develop these for our thermal league, but unfortunately they will not fly in the first contest but should be ready for the others.

To cut down on time the two progress reports will now be one as many of the activities are common to both the EMOYENE and the STILLETO.

Here are the latest photos


Completed moulds ,now we actually start building our first gliders.

After waxing, buffing,masking the moulds the colour is sprayed in.



























Next we lay up epoxy glass laminates as per the design requirements.
I am not to sure what the inside of the secretive EMOYENE has.
The STILLETO is full of carbon.
































STILLETO ready to pull from the mould and

EMOYENE out of the mould.

















































Product all ok, what a relief, in the next series of photos we cover the wings and a tailplane.
Stay posted.

THE HEAT IS ON.

Its a neck and neck race , both B.E.R.G. model glider development programs are moving along at the same pace ,rather hectic.
The reason is that the next season starts early January and it would be great to fly these new creations and see how they do.They need to be completed fitted out and trimmed before the competitions start. Below there are some more photos of the secretive EMOYENE build similar in many ways to the STILLETO but here and there some clever techniques thrown in, check out these .








Accuracy plays a big part in getting a good result.













This team as you well know are really serious they have developed special tools to help them ,this one will be known as the home made pencil ----facinating.









It is used as shown to mark the splitter board vertically below the fuselage plug , very neat idea.













This splitter is made up of several parts ,easy to remove off the mould later.


















Meantime more preparation goes into the plug. This is almost ready for paint.











Keep at it , the clock is ticking.

MODEL GLIDER W.S.B. PROGRESS REPORT

Well we have been sent more spy pics from or man on the inside, one of the Westrand Spy Bereau's leading agents.















Project Emoyene is now onto futher development of their stealth technology fuselage.













Looks like it has been filled and sprayed with an anti-radar detection MS primer coat.




































It's starting to look like a high perfomance R.P.G. remotely piloted glider to the layman.

More spy pics as we get them. Later dudes.

MORE EMOYENE SPY PICS

Well well the heat is on, development of the Emoyene sailplane appears to be more advanced than at first anticipated. Apparently outside help has been obtained in computer cutting the fuselage profile.These guys are obviously serious .








The plug is machined from maranti it will be interesting to see how it gets rounded.

















The tail end remains a mystery ,looks like a wooden bottle cap opener, but may be some kind of stealth technology.














Maybe its a tin opener or perhaps a V tail hummmm.

EMOYENE SPY PICS

Once again we are being allowed in on the secret development of this high performance prototype, the pink foam wing cores have now been bagged and the wing is taking shape.














From studying the photos it appears as if no spars are used, but the strength comes from the uni-directional carbon fibre skin.



















Interesting is the apparent di-hedral break built in during bagging by using a hindged building board ,sneaky clever.



















So what can we learn about building gliders fron these photos, tradional balsawood built up construction still has its place but it is slow and not as strong as the composites, foam cores bagged with epoxy glass is stronger,possibly more accurate , can handle the winch and can be built as a one off, to test flight characteristics. The last method is the fully moulded ship also composite construction fairly quick once you have moulds,light accurate and strong, models can be accurately replicated, a bit more expensive to make due to moulds.