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GP-14 VELO by Multiplex double carbon

I thought about writing a short construction report about this MULTIPLEX plane for a long time and finally decided to do so. Because the new GP-14 VELO by MULTIPLEX is significantly better than its reputation. In a german forum the aircraft and the construction are being trashed, which I personally cannot understand. I built the plane and I`m absolutely convinced by the quality and the flight performance. I think the development team at MPX did a great job with this model, and that’s why I’m sharing a few pictures of the building and nice flights in the mountains.

First of all, it is very commendable that there is a detailed, illustrated instruction manual available for the GP-14, which is a rarity these days. Various installation options are described, whether landing gear, FES or retract EDF, all information can be found in the instructions. The cockpit tub including panel is available as an option from Multiplex. Also a special carbon spinner and a white painted carbon prop is available. For this prop, the hacker service recommended a suitable engine for 6S setup, the A50-16S.

For the linkages in the wing, I didn’t use the standard linkages with Z-wire and fork head, but rather the extremely high-quality installation frames including rudder horns and pushrods from It couldn’t be more playful, rigid and elegant!I still had a pilot in 1:3.5 from Tailored Pilots which fits perfectly into the GP-14 VELO. I drew the rudder pedals in CAD and simply printed them out of PLA and painted them. Thae same I did with the linkage and control horn covers on the wings, they are also printed from white PLA.The 5000 battery is located directly in front of the wing joiner and with the pilot in the cockpit, not a gram of ballast is necessary in the nose for the correct CG!The finish is entirely realized with plotted vinyl stickers.

The power unit by Hacker allows very easy hand launchs and in headwinds, two steps for takeoff were enough. The A50 offers enough power to climb a good 45° with a current consumption of approx. 70A. So with the 5000mAh battery allows 6-7 climbs per flight.

The GP-14 performs fantastically both in thermals and in aerobatics and the pulling power is also very good for a model of this weight and size. With the help of the ACL glider lights on the bottom of the wing, the model can be perfectly recognized or found even at high altitudes or when flying on a slope with a changing background.

All I can say about the GP-14 is: Well done MPX!

25 years of Hacker Motor – Congratulations!!!

When I received my first F3A motor from Hacker in 2007, nobody would have thought that a few years later this small company would become THE reference brand in rc-aeromodelling. In addition to many of its own top products for electric flying, one of the leading remote control manufacturers, JETI duplex, is also exclusively in Hacker’s programme. And Rainer Hacker was the guy that I finally came across JETI at the 2016 toy fair.

I’ve been a pilot, partner and friend of Hacker Motor GmbH for over 15 years now – and I’m proud of that. During this long time, there have been many wonderful encounters and successes together with the team. I have summarized a few of them here:

30 years JETI model – Happy birthday!

For JETImodel’s 30-year jubilee they invited for a celebration and an airshow to Benesov, CZ. Next to all big european dealers such Hacker Motor from Germany, JETI UK, JETI Italia… there were also a few JETI-toppilots like Gernot Bruckmann, Markus Rummer or Roy Puchtinger invited. The famous Youtube-aeromodeller, RamyRC with his Airbus A350 airliner was there as well.

The friday started with a short and interesting review by Mr. Tinka (Jelen = JE, Tinka= TI) who showed how JETI started with 2 hobby enthusiasts around 30 years ago and is now a world leading manufacturer of high-class RC-radio systems with around 50 employees. It started with handmade ESCs for electric models, followed by 35-mHz receivers and the development of their own 2,4Ghz system and finally the duplex DC-16.
After the review it was time to hand over the birthday gifts from some guests to JETI and open end with good conversations.

On saturday was a big airshow with thousands of visitors. JETI joined this airshow with their celebration by traditional reasons. Benesov was the field where around 30 years ago the first JETI ESCs have been presented and sold to the first customers.

GeeBee R2 Restauration!

My passion for the GeeBee started at the age of 12 and has not changed since then. For a few years I flew an electric powered GeeBee equipped with a Hacker A200 and 2x 12S 5000mAh but sold it in 2019. Last year I had the chance to get another damaged R2 and decided to restore it and install a Fiala 250ccm 5-cylinder radial engine, the same engine I’ve been using in my Bücker for the past 2 years.

 The fuselage was damaged in different areas and it turned out to be much more work than expected. My procedure was as follows:

  • Opened the compressed areas with a cutter until the inner side of the sandwich. Removed the compressed and crumbled support foam.
  • Filled up the opened areas with thick epoxy and sanded it down
  • Put a layer of glass fabric above and sanded again
  • Puttied and sanded all
  • Fillered all fixed areas, sanded and reworked the panel lines with a fine rasp
  • Made rivets out of white glue
  • Repainted red
  • Slightly weathered with black oil color

 The effort was well worth and I am super happy with the result. I hope the model lasts long.

 When I bought the GeeBee I contacted FALCON to produce a scale prop in the correct size for the radial engine. And the result is a stunning 34×18 prop which fits and looks excellent. Even the measurements are almost correct compared to the full size.

 The equipment of the GeeBee is proven in my other models:  Hacker DITEX EL-3214 servos, JETI CB-220 with 2x RSat and RCSW. 2S Hacker ECO-X batteries, ClickConnect for the motor unit, EMCOTEC smokepump and 2 kevlar tanks by CM-Jets.

 In this model I used a gyro for the first time. The Cortex Pro by Bavarian Demon was my choice as it is the best system working with JETI model and can be set up directly from the transmitter, no computer needed. And it is connected straight between the 2x RSat and the Central Box. So easy!

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RT DESIGN Acrostar mk2 INFO!!!

The Acrostar 60E and XL is a very famous and well-flying aerobatic model. The produced batches of both version are sold out and no more available. Due to persistent requests for both models I checked together with Hacker Motor the possibility for a new batch of both models. But the price for the plane plus shipping and the high MOQ make it not possible to bring back these models.

So If you are a proud owner of a RT DESIGN Acrostar, take care of it 😉

Robin Trumpp, February 2023

Flugtag MFC Untermünkheim

Nachdem wir 2 Jahre Pause machen mussten, war unser Flugtag 2022 endlich wieder zurück – und wie!


In vielerlei Hinsicht sicherlich der beste Flugtag aller Zeiten in Untermünkheim!

Kurzum: Eine große Besucherzahl, jede Menge Toppiloten der Szene und kein nennenswerter Absturz.

Besten Dank an Andreas Maier und Oliver Büsing für die Erinnerungen!

Wir freuen uns jetzt schon auf ein noch größeres Fest 2023 bei uns:

50-jähriges Vereinsjubiläum am 24.+25. Juni 2023

Weitere Infos folgen.

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cool guys and classy airplanes!

Bücker Meeting 2022 in Landshut, Bavaria

The annual Bücker FlyInn took place on the 18th of June in Landshut. This event is a meeting for all full-size Bückerpilots and fans from all over Europe with their Bückers.

Herrmann Diebold, who is the key point of the Bücker scene in Europe, invited me end of last year to attend this event after seeing my video with the 50% Bücker from Friedrichshafen.

Luckily my friend Andreas Golla from Hacker Motor lives quite close to the airport Landshut and invited us to his house for a delicious BBQ and some hangout in his pool. An excellent refreshment during the hot summer day and good preparation for the Bücker FlyInn in the evening.

A real highlight was the Hangar 69 at the airport Landshut. There are some very nice airplanes including the original “Liesel Bach” Bücker Jungmeister. I was sitting inside the cockpit for a short time to feel the spirit of Bücker Jungmeister… but it´s better I stay on the ground with my radio 😉

Thank you very much for this amazing day with you!

SAB Tortuga V2

After having a lot of fun the past 2 years with SAB Tortuga I decided to build a new one (and call it V2) with some main modifications.


– clear canopy and new canopy lock system, 
– many 3D printed parts such as: servo cover, pilot, pump-, RX-, batteryholder

– light system by innoflyer


Servos: 2x Hacker Ditex EL0512W, 1x Hacker Ditex EL0510M
batteries: 2x Hacker / TopFuel ECO-RX 2000
RX: JETI duplex REX-7 + JETI RC Power Switch 5
Turbine: Kolibri T15 Autostart
Light System: innoflyer LD 3.0 + innoflyer LED´s: 2x Crystal red/green, 3x Lisa

1:12 Minimoa by Tony Ray / Pichler

After my stressful 5th semester at studies I had the desire to build something out of Balsa again. At the exhibition in Friedrichshafen I saw the kits of mini vintage gliders from Tony Ray at the Pichler booth. Right after the event I ordered a kit of Minimoa.
With the support of my 3D printer and covered with japanese paper and Graupner Spannfix  a really nice little vintage glider was born.
Check the pictures and see the progress of my little Minimoa.
Spannweite: 1422 mm
Länge: 625 mm
Gewicht: 330g
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