Page 58 - Jetpower (January 2020)

052-056 Mephisto:Layout 1 Englisch 09.01.2020 15:43 Uhr Seite 56

The fuselage side
was reinforced
with CfK, this
is where the
brackets of the
main tank will
be installed later.

The installed main tank.

The finished holder in the fuselage.

and screwed them tight. Last but not
least a lot of weight could be saved
on the fuel system. We did without
tank and hopper tank and installed
a bag tank from fuelbag.de. But this
posed the question of how to attach
a bag weighing more than four kilos
when full, so that it does not move
away from the troops without per-
The filled main tank.
The mount has alrea- mission in the case of high g-loads? After much deliberation,
dy proven I came up with an attachment consisting of half frames and
itself on various
flights. carbon rods, as shown in the pictures. So far it holds up won-
derfully, including rollovers and other flight manoeuvres. By
the way, this bag tank is filled via the "autofill" filling station
from VSpeak. This ensures that always the same amount of
fuel is filled up, so the fuel gauge integrated in the VSpeak
First I studied the building instructions. Unfortunately this is ECU converter always has correct data.
only available in text form at the moment and therefore not il- The slimming down has saved in total well over 1 kg of
lustrated. Let's hope that soon the CARF-standard constructi- weight. So this Mephisto in this equipment comes to a take-off
on manual will be available. Therefore I want to thank Frank weight of 20.8 kg dry. So you can still fill up with 5.5 liters. For
Westerholt again, he helped me whenever necessary. the model still sufficient, because it is flown in straight flight
After the monster was lying in the workshop, possibilities of with a maximum of 1 / 3 gas. And while we are already flying:
weight reduction were looked for. CARF does not make it ea- I was really excited and glad that I was allowed to fly and adjust
sy, because there is not a single gram that can be cut out just the model; Wolfgang Klühr was always raving to me about the
like that. But in the end we were able to work out a certain fol- super flight characteristics. What should I say after ten flights,
lowing potential. So we could optimize the servos. A total of 13 dear Wolfgang: You are right. To say that the Mephisto flies very
standard servos are built into the model. These should have at well does not fully reflect the flight characteristics. The Avanti S
least 25 kg of power. Why so many? Well, the model has two XXL from SebArt, for example, flies very well. The Mephisto
servos each for the vector and the elevator. Because that is con- simply flies differently! It flies light as a feather, goes by itself
trolled by a total of four servos! If we now assume an average through slow rolls, because the fuselage carries enormously.
weight of 75 g per standard servo, we can see that the MKS And is also extremely neutral in other respects. In short, it flies
DS9910XJ servo used weighs just 58 g at 26 kg force (at 6 V). ingeniously. Here the pilot is really the limiting factor.
This means a weight saving of 220 g for the servos alone. The
fact that the servos are powerful, run silky smooth and have a Summary
perfect resetting accuracy is an added bonus. We have shown that it is possible to build the Mephisto with
We have also discovered potential on the model. The air in- a KingTech 320G2 under 25 kg. And that, with a sufficient
takes in the fuselage go from the fuselage openings to just amount of fuel and without sacrificing safety. Hence "Mission
before the turbine. Part of the fuselage is closed from above. accomplished!"
All this fell victim to the electric foxtail and the power file. Fur- JP
thermore CARF had planned to control the landing gear
doors with one servo each. I cut out the landing gear doors

56 JETPOWER 1/2020