Electric Ducted Fan Model



April 98 - On the "Intermodellbau Dortmund" (Europe's biggest modeling trade fair) I bought a Vöster-kit of the Pampa. The model is designed for electric ducted fans, but may also be equipped with a .21 engine or for PSS.

A ducted fan with a nominal diameter of 90 mm must be used, best in combination with 12 to 14 Sanyo's (1700 or 2000).

I just began building it, so that I can only show a picture of the kit contents this time. The fuse is quite voluminous for a model with a wing span of just 44" and attracts immediate attention. It is glossy, lightweight (mine: 317 g) and reinforced with carbon at some sensible locations. The second big part is the one-piece wing, unfortunately with a leading edge still to be added and with a completely superflouos slot at the ailerons. Superflouos because these slots make the wing very fragile during the introducing labour as glueing the leading edge and sanding. Furthermore I usually do not build a conventional frame for the ailerons, so the slots are even more unnecessary.

The rest leaves a good impression, also the wood, which seems to be of excellent quality. The weight difference of the two wing tips for exemple is just 0.1 g!

The plane will be powered by a Wemotec Eco-Fan Pro with an Ultra 930-6 and 14 cells Sanyo RC2000.

Oct. 98 - The building of this model slowly proceeds, the remaining works are basically the internal installations as the air channels. The covering is done already, to make it simple I did this using white ironing film. There are not many interesting things to report. Only the "rudder" (balsa 3 mm) is too weak, so that it will loose its form during covering. I had to remove the covering again and fitted a spruce trailing edge to add stability.

New building photos will be provided for the next update. Here is just the ducted fan unit with the motor for now.

Here are the additional photos I promised you:

The fan unit in the fuselage (still without the breather channels)

Looks quite fast already, no? :-)

April 99 - Now I get a bit angry when I come to reporting about struggling with the intake channels. It reads very easy in the instructions but in fact it's very annoying. They are very soft, very thin plastic, consisting of several pieces which must be glued into the fuse more or less all at the same time...and you have no idea of a fixed point or something you can refer to. No fun at all. Perhaps the manufacturer should think about spending some money in glass fibre channels. The kit is not that cheap.

But...it is done now and there is just the canopy left, adding the R/C and some finishing. Maybe in 4 weeks or so I will present you the Pampa ready for take-off. :-)

Air intake channels from above...

....and from the front


May 99 - No further comment.

The Pampa could fly already...but is still too
white for my taste.
A look into the fuse with elevator servo (above the fan unit),
controller and battery pack.

A look inside from the front

The linkage of the elevators


June 99 - It is quite difficult for me to report of the first three flights (so far) in English. In short: the Pampa gives a lot of problems with the Center of Gravity and other issues. I'm still in the test phase and will report here how far the behavior of the Pampa improved. The first flight lead to a damage, however flights two and three followed one week later.

If you are able to understand German, please read here. If you are able to translate what you read there into reasonable english, please do so and let me know. ;-)

Some additional data of the finished airplane: weight all-in is little less than 2.5 kg (which is about 400 g more than it should be), current ist 41 A, the motor running time is about 2.5 minutes now.


(Click enlarges)

Bad behavior...but a nice airplane....

Dec 99 - Here is in brief the further story and the sad end of my Pampa

I made her new stiff sandwich ailerons (balsa - fiber glass - balsa). This was a real breakthrough in flight behavior, the Pampa flew like a new airplane from that very moment. In order to inrease flight speed, I also fitted a smaller outlet (part of 1.5 litre Coke bottle). This reduction from 85 to 75 mm did not result in any noticable speed increase, whatever theory may tell us...

The end came some nice september day, when I took the last curve before landing too slow and to sharp. This resulted in a stall and a crash. Damage is considerable (sorry, no photograph...), but I kept the wreck in my workshop...who knows...some day...

Oct. 01 - I was a bit lazy regarding this one, but now I want to continue my Pampa Story. This model is flying again for almost 1 1/2 year now with a new decoration. Repair and finishing was almost as much work as building new. In technical respect I upgraded the Eco Fan to a MidiFan (new rotor) and added 2 cells (16 now), another bigger modification apart from some minor inner changes is that  thanks to a very nice guy the Pampa has fibreglass air intake ducts now. 

The Midi Fan is a big step forward, it seems that there is much more glass in the resin now, so that the new rotor is much stiffer, thus providing considerably less noise and - I guess - also more performence.

The glass ducts
(click enlarges)

The new color scheme i saw on one (!) photo I found on the internet.

Full Scale...
(klick vergrößert)

...to model...

...here before a bungee launch in Hude, July 1, 2000


...to be continued