Double Trouble

The terrible twins are finally complete with thanks to all that contributed to the build. WELL DONE !!!
We are ready to take on the slopes of Hermanus next week. So watch out!

Sean on the left and myself on the SW Slipper face.

Flying Jarts in formation is not for the faint hearted

Filming Jarts ai'nt easy eather!

Give the file a moment & enjoy!

Baptism of fire

Yesterday, with the South Westerly wind blowing 80km/h, Sean and I decided to give the Red Bull Jart her baptism of fire and went up the Lady Slipper. The site is located on the highest peak in our area and generally works best on a South Westerly or North Easterly wind. The height above sea level usually provides ample lift.
80km/h winds are overkill to say the least!

One of a few landing attempts

Typical Jart Profile

Sean surprised that the plane was still in one piece

Wind speed indicator

Holding the camera in the wind was almost as bad as flying the plane, so look past the shakes!

Maitlands

These photos show our slope location at Maitlands, Port Elizabeth, South Africa

1. This is an overhead shot of the Maitlands slope that we share with the para-gliders

2. This shot is slightly above and along

3. A Google location for Maitlands

Red Bull Maiden

1. The Jart in her new party dress

2. Looking good

3. Looking mean and fast

4. Belly shot

5. Sean and Vic giggling uncontrollably!

Friday arrived with a moderate South Westerly wind at about 20 Km/h ( note the lack of white horses in the background!) We decided to toss her anyway and managed to trim her up in flight. The aileron throws need to be readjusted as the roll rate was nowhere near the old Jart. Wind strength did not help much either....

The main thing is she flew, and we'll put her through her paces soon!

Red Bull Jart

I know, I know....... just another Red Bull plane that" gives you wings"!
So what, I enjoyed building it and the stickers were lying around. The process also taught me the art of spraying and masking! I must have sprayed the three colours six times and taken it down as many. We are just waiting for a strong south westerly!
The plane weighs in at 1150 grams fully loaded and is perfectly balanced. I have given Alain my old one as it has had a tough life. It's been crashed and flown hard and still flies beautifully!
I must just ensure this one lasts so that we can take it along to Hermanus in November!
As Daron would say, YOU HAVE TO HAVE ONE OF THESE IN YOUR QUIVER"!

Johann & Daron

Finally we have a Jart the way it is supposed to be...... flown on the slope!
The wind was 25-30km South west on Monday and perfect for the Maitlands slope. The slope is not very high and therefore does not generate great lift, but if it blows directly up the face, one gets clean air. Daron was very apprehensive but maintained that the Jart wanted to fly. It is not the easiest plane to launch as there is very little holding space below the wing. I launched it with two hands and with very little adjustment on the elevator, it flew straight out. The plane flies beautifully!
Thanks to everyone for their support and useful advice.


Daron's yellow and black Jart

After getting the plane trimmed out, Daron was having such fun that I decided to join him and launched my more sedate Salto...... It has to be sods law, Five minutes later we had a head on in mid air... What are the chances?

WELL WE ARE BACK IN THE WORKSHOP!

Besides all the mishaps, we've had great fun and the plane really flies beautifully! We'll get the other one ready for it's trails. Lets hope it goes home.

It has been worth the time and trouble and we've learnt so much!

Finally we have reached the stage where we can launch and test fly our prototype!
If you look closely you'll see the blunted end of the Jart with the unforgivable prop fixed to the front! Vic being a purist was much distressed but agreed to come to the field and watch Daron do his thing.

Daron : the elected test pilot

I canabalised my hotliner, (composite Baudis Zoom) and removed the Axi motor and planetary gearbox. We knew the arangement would work as both planes have a similar all up flying weight of 1300g and fitted a 14x10 folding prop on a 28mm spinner. The nose had to be reshaped from it's oval profile to accommodate the spinner.

The actual launch was pretty uneventful except for a twitchy left and right wiggle as Daron adjusted his fingers on the controls. The motor arangement can take the plane up vertically and by the time Daron cut back the throttle back, the Jart was a tiny speck in the sky.

That was when the problems began......

Daron failed to level out before cutting back and the plane entered a stall and seemed to drop a wing. Besides being so high up our colour scheme did not help with the oriontation and the plane never recovered from the spin. Hard to believe with all that height to play with. We have come to the conclusion that it was all pilot error!

The plane hit the ground nose first on a hard surface. Th amazing thing is that there is hardly anything wrong with the plane. The motor gearbox, prop and elevator servo are buggered, but for the rest the plane is still intact with marginal damage to the wings and fuse.

It was rather distressing, but we'll try again! Just waiting for parts.

Vic's pulling his nose at the thought of a prop!

At this stage the going has not been to good with two flights and two crashes. The first was Vic's balsa prototype in a 100km/h wind and Daron's disoriontation....

Third time lucky!

Johann, Daron & Vic

Finally some progress!
When you receive e-mails stating " I keep looking on the JART-SA blog hoping to see someones Jart progress but nada, niks, and zero." you know the pressure is mounting.
Well to recap, we shaped and glassed plug number 2. There was some debate as to the finishing coats and unfortunately we applied some epoxy coating that ended in disaster. The full curing time was 10 days which conveniently fell over the Christmas holidays.

Plug number 2

Epoxy coating gone wrong

Gel coat and epoxy coating in a marriage gone wrong

Not quite the best spray booth.

Dejavoux

Plug set in the splitter board

The plug still stuck in the mould, but salvaged

De lamination of the K2, probably due to the adhesion to the

epoxy finishing coat remaining in places after sanding.

And finally! The mould had to be cleaned off, but

came out beautifully

4mm studs used as locating lugs

Layup complete and curing

Bench flying!!!!

The fuse seam joints have been a bit of a headache. On this one we tried a wet joint as we have been to scared to cut the mould to enable us to work on the seams. whilst the joint is sound, the overlaps have folded in places.

On the following fuse, we will try smaller overlaps and two pairs of hands!

Thanks for all the continued advice and support.

Thanks for all the support and guidance especially from Evan and Mike. It seems like this has turned into a bit of a process....
I have not had a chance to respond to your e-mails, but I'll get there!
Evan, we managed to get the coating that you recommended for the plug. We tried several places and between only selling the paint in 5l tins at R1600.00 we finally managed to get a litre. I hope it is the correct one! the trade name is SIGMAGUARD HS which is described as a two component high solids polyamine cured epoxy coating and comes in a green grey colour.
The curing times seem to be a bit of an issue as it is described as 20 hours min between coats and 10 days for final cure.....
That means we will only cast our moulds in January......
Vic has given up on us and has proceeded to build a fuse out of balsa. (He has the time and it's his preferred building technique anyway) It may be a blessing in disguise as we can use the prototype to iron out all the gremlins. We'll post some pictures as he progresses.

Meanwhile Daron and I can dream about our future composite plane and colour schemes whilst we wait!


Mmmmm Daron likes black and yellow....

Hi there Mike, Evan & Vic

Thanks for the support that you have provided so far. I must say that some things you mentioned are so logical that I can't believe we never thought it thru such as casting the otherside of the mould without removing the Plug.


Plug number 2


Anyway, The new plug has been shaped and layered up with one 50g cloth and one 200g layer. We have re sanded and got back to shape with minor blemishes.
Should we put on another layer of glass, as I noticed the previous plug developed small pressure indentations during the final sanding and polishing phase?

Our wings are progressing well with some help from Vic Oxley who is an old hand at constructing built up wings. He has kindly undertaken to construct the wings for us. We would love to try bagging, but without a vacuum pump and the suitable knowledge, we will leave this process in abeyance for the time being.
Vic has been building and flying in our area for the last thirty years or so!


Vic Oxley hard at work in his workshop


The foam cores have been cut and he has elected to build a balsa covered wing which poses a bit of head scratching as regards the fixing of the wing to the body.

The thought has been to cut the"canopy" opening down to the bottom edge below the wing so that the wing can be bolted down to the lower section of the fuse and the enlarged canopy will be shaped to the top of the wing profile. It may help to have a removable wing and we are looking to put a centrally placed servo for the ailerons....
We're getting ahead of ourselves!

Thanks for all your positive comments and support.
Kind regards
Johann & Daron

Johann & Daron

It all starts somewhere......
It was about messing around on the Internet, browsing to see what planes were around, when we happened to come across the Jart web site. After looking around the local builders and seeing Adrian's build thread it made us believe we too could build this plane..... how hard could it be?
The fact that neither of us had built a scratch plane (balsa or glass), other than damage repair, did not deter us.
We sourced some Iso board and shaped the plug... so far so good
Then read up on all the epoxy and paint coating specs.....
glassed and painted....
( not without mishaps)
And we were the proud parents of a Plug!!!!
All shiny and smooth.
This was then laid up as described by Evan and others

My daughters got so exited when they saw their Dad busy with blue paint that they volunteered to help....

This only lasted for 5 minutes until they discovered that it was all gooey and did not come off.

The splitter board came off with no problem.

And......

It STUCK.....

I'm trying to get over it!

I must admit it's hard not to just give up.

I'll give it a day or so to come to terms with my short comings...

I suppose it's part of the learning curve and life's rich tapestry of experience.

We'll post some more pictues of our next build....