Urupema – wings and preparing for fuselage mould

After last week’s styro cutting we have now started building the wings. Georg is building his own, Andi and I are building the other three pairs. Today Andi and I bagged the upper side of wing nr.1 (out of 6), having prepared all the styro cores and abachi inlays yesterday. As you can see on the pictures we are going for a full carbon layup (between styro and abachi, 160gr inner side of the wing, 100gr outer side of the wing, with an extra 160gr inlay in the area of the wing joiner and an extra 100gr layer underneath the servos.

In the meanwhile Georg has finished the upper sides of his wings and has worked hard on preparing the plug for building the fuselage mould. With a bit of luck we should be able to build the first half of the mould this week still.

And in the meanwhile Project Urupema is picking up speed

In parallel to finishing my JS3 we’ve been making good progress on the Urupema project. Georg has made the moulds for the rudder and wheel encasing. Last week we finished the stamp for the canopy. Today we finished cutting the foam for the wings (four pairs!). In the meanwhile I’ve been building wing joiners and Andi and Georg have been busy producing four horizontal stabilisers. Next step is building the wings and the moulds for the fuselage.

JS3 Fuselage almost done

Bad weather means workshop time. The JS3 fuselage is as good as done, all servos installed, wiring ready, decals done. I’ll be using the Dualsky Gemini 3018 for the first time, curious to see how it will work.

Next step is the seal at the top of the wing control surfaces (resin with micro balloons) and installing the wing servos. Still a lot of work, but it’s nice to see the work entering the final phase.

And then there’s still my JS3

Work on our JS3s is still ongoing. Andi finished his JS3 a few weeks ago (top picture), and we hope to maiden it soon. Richie and I are still working on ours. This week I finished polishing the fuselage and wings, cut the wing surfaces, set the silicon hinges and have started installing the electronics in the fuselage. Still a lot of work to do, but I’m slowly getting there.


Urupema Moulds

After a summer with some great flying the weather has now definitely turned autumn, which means time to head back to the workshop. Georg has started work on the smaller moulds for the Urupema project. We need moulds for the canopy, rudder, wheel encasing and of course the fuselage. Work on the first three is well advanced, and Georg has also started on the wing joiner and ballast pockets (last picture). Georg and I will be doing the mould for the fuselage in January. In the next few weeks we also expect to start work on the wings and elevator, which we will be doing in our usual styro core with carbon, abachi, glass and then spray painted. Georg has chosen an extremely thin wing profile….an interesting experiment. It should be quite a fast plane :-).



Urupema Plug ready

It’s been a while since my last post. The fantastic weather so far has meant little time in the workshop and a lot of time flying. Unfortunately I badly damaged my AvantiHawk in a bad launch in Hahnenmoos, which has meant quite a few hours of work fixing it. It should be airborne again soon. In the meanwhile Richie has been working hard on the Plug for the Urupema. It’s now ready, see pictures below. The plug is now with Georg for the next step: the moulds for the canopy, plug and wheel cover. Georg will be doing the preparatory work over the next few weeks. As soon as we have one or more days of rain we will get started on the canopy mould.

Urupema plug progress

While I’m struggling to find time to finish my Baudis Diana2, and still have a lot of work on my JS3, members of our team are making good progress on our new project, the Embraer EMB400 Urupema. Richie, our shaper, has finished the rough shape of the plug for the fuselage. Georg finished building the elevator, and has now started the careful and extremely important work of positioning elevator and wings on the plug. After that Richie will put another layer of glass over the plug, add filler and start the final sanding and polishing. Then Georg and I will build the moulds.

Baudis Diana 2 (1:3 – 5m)

As a huge Diana2 fan I couldn’t resist ordering a Baudis 1:3 version last summer. The plane was delivered a few weeks ago. Now that the AvantiHawk is airborne getting the Diana2 ready will be my priority for the next few weeks. Fortunately the amount of work that still needs to be done on this is limited – fitting canopy, motor and retractable gear, as well as the rudder servo. The wings and elevator servos are already installed. Initially I intended to build my own fuselage with this plane (we have moulds for our own 1:3 Diana2), following the example of Georg, one of the other members of our “building team”. Seeing how much work was needed to adjust the fuselage to the wings, and being unable to resist the urge to fly this plane during this season rather than only next year, I decided to go with the original Baudis fuselage instead (which Dani from Chocofly was able to deliver on very short notice, thanks Dani!). Unfortunately the Baudis fuselage is quite “anorexic”, compared to our own fuselage, so I may still want to do a self-built fuselage sometime in the future.

Maiden flight of the AvantiHawk!

This afternoon Georg and I maidened my new AvantiHawk on our club’s airfield. I started using the bungee (check out the video), and you will see in the bungee that it was a bit too agressive on the elevator (and on the ailerons). First flight went quite well though, stayed up in the air for 45 minutes using only a few minutes of motor. After adjusting the settings the second flight went much better. It seems that we got the center of gravity correct, and I’m not too far off with the other settings. Today’s conditions were not very favourable, and of course the real testing will come when I fly this baby on one of our favourite slopes, but what I saw today impressed me. This is one great little glider…

details: 4.12m wingspan, fuselage, rudder and elevator scratch built (Fuselage built by Richie), wings from the Chocofly Avanti, kindly supplied by Dani from ChocoFly,  5.8kg flying weight, all servos ChocoMotion, except the elevator (MKS). Motor is a Dualsky/Leomotion outrunner with a Castle Light 100A ESC and 2x 3300 3S Lipos.

Urupema Fuselage Plug taking shape

Our fuselage shaper Richie has been working hard on getting the fuselage plug into shape. It’s starting to look like the real thing. Over the next few days Georg will finalise the elevator design and we will start cutting the foam cores of the elevator, after which Georg will build a first elevator, so that Richie can use it to finalise the fuselage plug. Georg has also started the design of the wings. More on that later….

The AvantiHawk is ready for its maiden flight!

The final bits of work are always more than planned, but over the weekend I finally managed to get the AvantiHawk ready for its maiden flight. I’ve set the CoG at 100mm for now, which is how colleagues fly the Chocofly Avanti (my AvantiHawk uses Chocofly Avanti Wings). Flying weight is 5.8KG with 2×3300 3S Lipos and a small Scorpion backup power system. I’ve built it so that I can fly it with 2×3700 3S Lipos as well, as well as a heavier Life backup power system that we developed in our club. Now all I need is the right weather….. In the meanwhile my JS3 also came back from the paintshop and I got the fuselage for my 1:3 Diana2. The Diana2 has priority and I hope to finish it in the next few weeks, after that it’s back to the JS3 again. More on that later.

AvantiHawk is back from the paint shop

I just got the AvantiHawk (Duckhawk with Chocofly Avanti wings) back from the paint shop. Andi did a fantastic job, as always. Unfortunately I missed quite a few pinholes when preparing the fuselage for painting, but I hope to be able to correct this when polishing the fuselage.

Now I first need to wait a few days for the paint to harden out, then I can polish the fuselage and rudders, and finish the elevator as well as install the electronics in the fuselage.

JS3 off to the Paint shop

On Friday I finished all the sanding and put the plane together for a final check. It’s now ready to go to the paint shop (the elevator is already there). It’s such an awesome looking plane, I can hardly wait to fly this one! The pictures below show both the 18m and the 15m version (we did two sets of outer wings). Unfortunately it will take a while to get it painted as the paint shop we use is pretty busy. I do however have two other projects to work on during the wait. More on that later….

Start of the next project….Embraer 400 Urupema

Although I still have enough work on my JS3 and AvantiHawk to keep me busy for a while (and there’s a Moswey III waiting to be finished as well), work has started on the next project. The same team that built the JS3 has decided to have a go at a 1:3.5 scale version of the Embraer 400 Urupema. It’s a Brazilian glider that was designed in the mid-1960s and that maidened in 1968. We got hold of some (very) rudimentary plans. Our shaper, Richie, has started work on the fuselage plug, using the rudder that Georg designed and that Georg and I cut a few weeks ago. We’re not a in a hurry, and it will take a while still until we can start work on the moulds, but it’s exciting to see the new project taking shape!

JS3 Winglets and Canopy

While the AvantiHawk (Duckhawk) is still waiting at the paintshop, I’ve picked up work on the JS3 again. The winglets were a lot more work than expected. The crude mould we used to shape carbon around a foam core proved a bit too rudimentary. The result needed a LOT of work (filler, sanding, repeat….), but I’m now almost there. I’ve also finished the canopy frame, and cut the canopy glass to shape. All that’s left is a final sanding of the winglets and fixing the canopy glass to the frame. Then the fuselage needs a final sanding and a bit of filler to cover up the seam where the two halves of the fuselage were joined, and then it’s also off to the paintshop.

AvantiHawk off to the paintshop

It’s been too long since I’ve been able to post an update, also due to the hours spent on the new EU legislation on unmanned aircraft, which has now finally been completed and where we managed to convinced the EU to make a range of changes to better accommodate the concerns of us aeromodellers. Add to that the amazing weather, which meant an early start of the flying season :-).

In between other tasks I’ve made much progress on my AvantiHawk (Chocofly Avanti Wings with scratch-built Duckhawk Fuselage). Fitting the wings to the fuselage was more work than expected. It’s the first time that I’ve had to adjust wings to a different fuselage, and I’ve lost count of the amount of times that I had to sand, apply primer of resin with micro-balloons, and sand again, to get a halfway decent result. On Saturday I finally gave it to my friend Andi who will paint the fuselage, Canopy frame, elevator and rudder. I’m keen to see the result.

In the meanwhile….AvantiHawk!

Although our JS3 build is progressing steadily, the long time in between allowing the epoxy resin to harden out for each of the current steps of the build leaves a bit of time to work on something else. I’ve been looking for a relatively light (around 5.5kgs, easy to hand start) scale 1:3.5 glider to use my favourite local slope. A couple of months ago one of my friends gave me a surplus fuselage of a 1:3.5 Duckhawk that he built a few years ago (see this amazing video of a very lucky “touch and go” of his DuckHawk!). I’ve always like this plane, with its very characteristic fuselage, rudder and elevator. As I don’t time to build another pair of wings now, the question was whether I could use commercially available wings. I was very impressed by the new 4m Chocofly Avanti, designed within our club, and liked the quality of the wings, built by RCRCM in China. Dani (Chocofly’s owner and a member of our club) was able to provide a pair of custom built/painted Avanti wings in less than a month. I’ve spent the past few weeks building the elevator and rudder and fitting the motor and canopy. Today Georg helped me fit the Avanti wings. I’m very proud with the result – in fact I think it looks even better than the original (which has very narrow wings). There is still quite a bit of work to do, but I’m very much looking forward to flying this one!

JS3 Winglets….

Ok, we now officially decided that the JS3 is the most difficult build we’ve taken on so far. We’ve spent quite a bit of time cutting and rejoining the wings to that they get their nice multiple V shape. Now we’re working on the winglets. As we are building both the 15 and 18m versions, we actually need two pairs of winglets for each plane (they’re fitted to the wing at a different angle for each version…). Georg kindly prepared two simple moulds that he used to construct his winglets. The core of each winglet is foam, cut with a hot wire, then covered with carbon. After fitting them to the wings and sanding we add a layer of glass, then primer, sanding again, and finishing off with spray painting. But first we need to produce four pairs of these.


Back to work on the JS3…

We’ve had quite an amazing summer, with fantastic weather, and many days spent flying on our airfield and slopesoaring in the mountains. The great weather also meant that I spent very little time in my workshop, and the time I did spend there was mostly to maintain my planes. In addition I also worked on two other builds: a prototype of the Chocofly 2.8m Taranis with outrunner, and a Wistmodel SZD54. The Taranis was maidened a few weeks ago and is by far the fastest glider I’ve ever flown. More about that later. The SZD54 is still under construction and should be finished in the next few weeks – if we get a few rainy days.

All of this also means that Andi and I had little time to work on our JS3. Last week we started working on our JS3s again. We intend to finish them this coming winter and maiden them early next year. Last week we finished fitted the wings to our JS3 and this week we finished covering them in glass. Next week we will paint the wings with filler and sand them to the final shape.

In the meanwhile Georg’s JS3, the first one built under our project, has spent well over 50 hours airborne. The more he flies it, the more we’re impressed. The performance of the 5.14m (18m) version also in weak thermals is unequalled by any scale glider I know. Last week I flew both my 1:3.5 Diana2 and my 1:3.5 SB-14 in weak thermals and had to land after 45mins at most. Georg spent well over two and a half hours airborne, picking up the slightest of thermals on our airfield. The 4.28m (15m) version has also been put through its paces on the slope. It’s fast and agile and as good as, if not better, than our Diana2 (the verdict is still out on that :-). Georg is still tweaking the plane’s settings and programming, and the performance continues to improve almost every time he flies it. I’m so much looking forward to flying mine early next year!

Here’s a short video of Georg’s JS3 shot last week of a flyby in weak thermals.



JS3 Slope Tested

We spent a week flying at the Hahnenmoospass (near Adelboden, Switzerland) where we also slope-tested Georg’s new JS3. He flew both the 5.14m (18m) and the 4.28m (15m) versions. Both versions performed very well. As expected, the 18m version thermals very well and is very stable, whereas the 15m version is more agile and faster. As Georg continues to fine-tune the plane’s center of gravity and longitudinal dihedral the plane’s characteristics continue to improve. It’s a beauty to see and fly. Check out the video of the first slope start. One of the best flights was when Richie was piloting his scratch-built 1:3.5 JS1, the 21m version, together with Georg’s JS3 in its 18m version. Great to see the two planes with their characteristic wing shapes thermal together.

During the last flight the JS3 was involved in an unfortunate mid-air collision. Fortunately the JS3 survived without major damage, just a few paint scratches and bruises along the entire right side of the fuselage. With a bit of polishing and new decals the damage should be hardly visible. The other plane, an old Alpina, whose pilot caused the crash through a thoughtless maneuver that caused it to crash into the JS3 from below, suffered major damage.

Check out some of the photos below, including a group picture with my scratch-built Diana1.