Hello
I would like to introduce myself, I am Dennis from the Netherlands. I have been a fanatic model aircraft builder and flyer for over 25 years and competed in international level for many years. A few years ago I was looking for a new challenge which I found by building an RV-12. After obtaining my pilots license I ordered a RV-12 kit which I started building at Christmas 2011, after two and a half year of building I made the first flight on August 31st. I would like to share some of my experience of building and flying the RV12 with you.
Based on my background with model aircraft I decided to modify and add many parts to my RV12.
Below are some of the changes I made.
Fairings
Most of the added parts are fairing in an attempt to reduce the drag and improve the appearance.
Fairings added are:
Horizontal stabilizer tips, to give them a rounded tip.
Between the wing and fuselage. This smoothens the junction making the rubber squeezed between the fuselage and wing invisible.
Between the fuselage and the fin. To smoothen the junction.
From the wheel covers to the fuselage. The standard lag is square which isn't the most aerodynamic efficient shape, therefore I covered the leg with a fairing that connects to the wheel cover and the fuselage, see picture below.
A vanity panel above the instrument panel to hide the canopy tubing.
Weight reduction
Next to that I have reduced the weight of many of the standard composite parts engine cowl, wheel covers, tail cone, by using sandwich composite construction. Whereby I laminated a honeycomb material in between two thin composite layers. The added thickness created by the honeycomb increases the stiffness tremendously whereby less layers of composite are needed, thereby reducing the weight. Resulting in a empty weight of 731lbs.
Elevator trim improvement
Based on articles on this forum and some initial tests on the workbench it seemed that the elevator trim was difficult to control accurately. Making fine adjustments over the complete flight envelope is impossible. I wanted to improve this to make the system more robust. Therefore I requested a friend, with an aerospace degree from University of Technology in Delft, if he could help me. I wanted to keep the system as original as possible such that the standard trim servo with its build in safety mechanisms would remain untouched, as well as the wiring loom through the aircraft.
After some initial prototypes this resulted in a system whereby the whole travel range is divided into 200 equal steps controlled by a new instrument in my cockpit (standard 57mm mounting). On this instrument I see a digital readout of the position of the elevator which can be controlled to increase/decrease with 2 buttons on the instrument or on my control stick. In addition there are two more buttons on the instrument to store preferred positions. To ensure the safety of the device there is another part mounted in the tail next to the servo motor, this part converts the position measured by the servo from a voltage into a coded signal. This makes the systems insensitive to outside disturbances or changes in resistance of the wiring (for example by aging connectors). It is even able to detect when the system is damaged, and will report this back to the display.
Flight experiences
The RV-12 flies very well, and am enjoying it a lot. It uses very little fuel and can fly very fast.
The trim instrument has been impressive especially the digital readout which shows the position indicated between -99 & 99.
And the two memory positions are great. When I take off I push one button shortly, whereby the trim goes to the take off position. And after reaching cruise speed I press the second button to bring the trim to its cruise position. While still allowing me to make fine adjustments, even at high speeds.
Below are some pictures of the RV-12 during building.
Best regard,
Dennis
I would like to introduce myself, I am Dennis from the Netherlands. I have been a fanatic model aircraft builder and flyer for over 25 years and competed in international level for many years. A few years ago I was looking for a new challenge which I found by building an RV-12. After obtaining my pilots license I ordered a RV-12 kit which I started building at Christmas 2011, after two and a half year of building I made the first flight on August 31st. I would like to share some of my experience of building and flying the RV12 with you.
Based on my background with model aircraft I decided to modify and add many parts to my RV12.
Below are some of the changes I made.
Fairings
Most of the added parts are fairing in an attempt to reduce the drag and improve the appearance.
Fairings added are:
Horizontal stabilizer tips, to give them a rounded tip.
Between the wing and fuselage. This smoothens the junction making the rubber squeezed between the fuselage and wing invisible.
Between the fuselage and the fin. To smoothen the junction.
From the wheel covers to the fuselage. The standard lag is square which isn't the most aerodynamic efficient shape, therefore I covered the leg with a fairing that connects to the wheel cover and the fuselage, see picture below.
A vanity panel above the instrument panel to hide the canopy tubing.
Weight reduction
Next to that I have reduced the weight of many of the standard composite parts engine cowl, wheel covers, tail cone, by using sandwich composite construction. Whereby I laminated a honeycomb material in between two thin composite layers. The added thickness created by the honeycomb increases the stiffness tremendously whereby less layers of composite are needed, thereby reducing the weight. Resulting in a empty weight of 731lbs.
Elevator trim improvement
Based on articles on this forum and some initial tests on the workbench it seemed that the elevator trim was difficult to control accurately. Making fine adjustments over the complete flight envelope is impossible. I wanted to improve this to make the system more robust. Therefore I requested a friend, with an aerospace degree from University of Technology in Delft, if he could help me. I wanted to keep the system as original as possible such that the standard trim servo with its build in safety mechanisms would remain untouched, as well as the wiring loom through the aircraft.
After some initial prototypes this resulted in a system whereby the whole travel range is divided into 200 equal steps controlled by a new instrument in my cockpit (standard 57mm mounting). On this instrument I see a digital readout of the position of the elevator which can be controlled to increase/decrease with 2 buttons on the instrument or on my control stick. In addition there are two more buttons on the instrument to store preferred positions. To ensure the safety of the device there is another part mounted in the tail next to the servo motor, this part converts the position measured by the servo from a voltage into a coded signal. This makes the systems insensitive to outside disturbances or changes in resistance of the wiring (for example by aging connectors). It is even able to detect when the system is damaged, and will report this back to the display.
Flight experiences
The RV-12 flies very well, and am enjoying it a lot. It uses very little fuel and can fly very fast.
The trim instrument has been impressive especially the digital readout which shows the position indicated between -99 & 99.
And the two memory positions are great. When I take off I push one button shortly, whereby the trim goes to the take off position. And after reaching cruise speed I press the second button to bring the trim to its cruise position. While still allowing me to make fine adjustments, even at high speeds.
Below are some pictures of the RV-12 during building.
Best regard,
Dennis
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