This is an article in french I wrote for the french federation of aeromodelling (FFAM). You can download the full article here. Time to practice a bit your french language :) !!!
Saturday, March 22, 2014
Planet-Soaring blog (http://planet-soaring.blogspot.fr/) reached 1 million visits last night since the counter is active, that is to say october 2009. But Planet-Soaring story started back in 1998 with a first webzine named RC Soaring Magazine. Few years later, because of a domain name transfer issue, I created the domain name planet-soaring which is linked to the blog.
A big "thank you" for your support and loyalty !
Friday, March 21, 2014
Thursday, March 20, 2014
This new video from Steve Lange features an ultra light aerobatic glider doing crazy aerobatic at low speed and close to the ground. It's like the plane is a feather, looking so light. Is the plane inflated with some Helium ?
Sunday, March 16, 2014
This superb video posted by didier Hamond is featuring 2 Excalibur VTPR gliders (piloted by Christophe and Michael) flying synchronized at slope, near Saint Brieuc (I guess). This has been made possible because plane are identical, so same evolution speed. With the addition of the right music, the show becomes simply magic !
Friday, March 14, 2014
Thursday, March 13, 2014
I posted last august some information about this Romanian aerobatic plane. Thuro, from Austria, is currently making a 5m version of this plane. Thuro made good progress and sent me these pictures of his really nice looking and original aerobatic plane:
Wednesday, March 12, 2014
The coincidence Weather/Libelle is very good because at the moment in France we have very high pressure for few days and consequently a sunny weather with no wind at all. so it was really the time to try such type of sailplane ! I did the maiden flight at the local slope with no wind, then the day after, we flew at the Pierre Percée, a nice place to make a shooting session, with plenty of snow and still no wind. So what to say about the Libelle:
Using normal technique (by the fuselage), the launch is pretty easy, but the height reached is not high. With the discus launch, it is much better. I'm a total newbee in this, so doesn't have the technique at all. With my onboard altimeter probe and telemetry, I recorded my best launch at 25+ meters. I expect an experimented launcher to reach 35meters and possibly a bit more. Pilots expecting the Libelle to compete with high end fully moulded HLG will be disapointed, but the airframe made mainly of foam is not rigid enough and it is everything but a surprise. However this altitude of 20 to 25m is enough to catch thermal, explore the field and enjoy flying. Remember the goal of the libelle, as explained by the designer himself: HLG for everyone !
The Libelle is a pure joy to play with. It is very agile, light at the sticks. It shows a good cruise speed and penetration, and it can circle literally on the wing tip. The efficiency of the rudder is excellent and I surprised myself by using more the rudder to trigger the turn, than the ailerons. I found that the 3 camber positions give really different behaviors. A the neutral position, the plane is already fast and can explore the field easily. in Reflex mode, speed is a bit higher (launch, aerobatics). In thermal position, with only 2 to 3 mm, the plane slows down greatly allowing to "work" the thermal, center it, and extract as much heigth as possible from it. At the opposite of this dymamic/active flight where you alternate transition and circling, The libelle is also very good at low speed. you can slow down it a lot, given that the stall is very very late and very gentle. When the air is very neutral, you can, like this, stay in the air longer, optimizing the sink rate. On my transmitter (XG8) I can change the camber rate with a trim, so I can adapt the camber to the conditions.
Despite it is not designed for that, when you got some height then you cannot resist so let's do it. Vertical manoeuvers (reversal, and looping) are lacking of amplitude because of the low weight. Some reflex (launch position) however helps a lot as the plane accelerates better. Rolls and even 4 steps rolls good, well axed. Inverted flight with reflex camber is a piece of cake.
Catching the Libelle is very easy, but I recommend to catch it by the fuselage, not by the wings or you will "compress" the leading edge foam and at the end let some marks. The landing position of the flaps slows down greatly the plane which is a plus to prepare the catch.
The libelle is very innovative in its design and construction, affordable, an provide lots of pleasure during the assembly (the kit is clever and well thought), and even more in flight. Without competing with high end HLG, it is however allowing you to touch the essence of this popular and beautiful discipline. After flying and enjoying the Libelle for few days already, I predict that it will quickly become a best-seller like the Alula and the Weasel were in the past.
- wingspan 1200 mm
- wing area 21.31dm2
- weight 278-290 gm (Mine was 275g)
- wing loading 13-13.6 gm/dm2
- Price: 120$
- Manufacturer: Dream-Flight
Below is a video filmed during the afternoon when I maidened the Libelle.
Monday, March 10, 2014
As I always do different from the assembly manual, I started by the fuselage. First of all, I glued the pastic control horns on the rudder and the tail. As there is a recess, you cannot be wrong. I used medium type CA from R&G. I use cotton bud to wipe away excess glue.
Then I fixed the tail in place with the plastic screw to have a reference, then glued the fin in place on the boom with a quick check using a 90° square. I didn't add the small piece of tape overlaping onto fin as mentionned in the manual. I don't think it is needed.
Next step was to install the elevator and rudder servos in place. I used 4 x Power HD DSM44, metal gear, digital servos I had for a while for another foamie project. Being a bit higher than the recommended HS-35HD, I digged a bit the foam, till the plastic shell in skid. Servos are glue using some Uhu-pore neoprene glue. Now we can install the pushrods. The shorter one is for the elevator, the longer for the rudder. The Z-bend end is on servos side and the clevis is on control surface side. The celvis is asymetrical by design, so has an orientation, screw head on top for the rudder, screw head on right side for the elevator. screw the clevis, but not too firmly yet on the carbon pushrod, install the pushrod into the boom, connect on the servos, then plug the clevis on the control surface, and adjust the clevis position before to tighten the screw on the clevis.
In install the receiver on its side in order to have the ailerons pin (channel 1 & 2) accessible. I did a small extension from the receiver to the batterie, no switch. Some small pieces of EPP or hard foam are cutted to immobilize component.
Let's start with the wings: As indicated in the assembly guide, gluing the 2 wing panels together is the most delicate operation. First, I glued the 2 dihedral brace in place by applying some medium CA to recesses, then put the braces in place. Same operation for the second panel, except that you need also to apply CA on the root face areas. This is the step where you need to by quick, precise, and not dirty if you don't want CA everywhere. Medium CA allows to have few seconds to position the 2 panels together. Once done and dry, you can glue the center wing plate located on the upper side center.
Before to install the servos, I glued the control horns (same as rudder and elevator). The ailerons servos being a bit longer thant the recommended ones, I remove some foam before to glue the servos in place with the arm in place at the correct neutral position with some Uhu-pore neoprene glue. Then I connected the wire extensions and installed in their channels. I used some blenderm over wire channels and servos. Like for the rudder or elevator, the pushrod provided are already at the correct lenght, with a Z-bend end to connect on the servos arm, and a plastic asymetrical clevis to connect on the control horn. Just left he launching peg wich is a small piece or carbon tube you need to sand before to install. Several attempts are needed before you have sanded enough for the tube to be install firmly.
Let's finsish with the balance. I neede 20g of lead (5 gr under the battery, 3 x 5gr on the side of the battery) to obtain the CoG at 5mm behind the carbon spar, which correspond to the rear limit indicated on the assembly manual.
Balanced, my Libelle is 275g. I added few strips, that are painted with specail Elapor spray. It adds good visibility in flight.
Overall the assembly went very well. No bad surprise, everything is carefully designed, clever, simple. It is a pleasure to build kit like this, when you don't need to replace, rethink things.
Next time, I will do the maiden flight report. Stay tuned !
Wednesday, March 5, 2014
Today, I received one of the very first Libelle kit from Dream Flight. The Libelle is a 1.2 meters DLG designed for the modeller who wants to discover the hand launch glider category without emtying his wallet. According to Michael Richter, the Libelle has been designed to be compact (giving more clearance during the discuss launch), with a lower aspect ratio to improve low speed turning abililties, in combination with large control surfaces. Lets have a look to the kit content:
The wing panels: They are very nicely moulded, no extraction marks on the upperside, some very small ones underside, but good point, no ugly injection points. The servo and wire prints (including lead extension plugs) are molded, as all the necessary prints for plastics part to assemble the wing panels together. Wing panels have the carbon spar (flat carbon rod) in place and also a plastic part located on each wing tip to receive the launching peg.
Fuselage and Canopy: They arrive already assembled with the carbon boom, the wing fix system in place, the 2 magnets to secure the canopy, the tail mounting piece.
This is a very good point, because it saves assembly time, but especially it guarantee the aligment between the wings, the tail and the rudder, which is essential on those type of sailplane.
The front fuselage is from Elapor with a plastic shell all around, providing some robustness.
The Tail is also ready to use with carbon spar and plastic mounting part. The rudder is ready to glue on the boom.
A plastic bag includes all the accessories like control horn, clevises, wing panel center joiner parts, the peg, and a small piece of sand paper.
The Libelle has been molded around 4 Hitec HS-53HD sub-micro servos for wings and rudder elevator, but any equivalent can be fine with no or little modifications.
Finally, the kit includes a very nice and well written assembly manual, the kind of manual made with passion, with plenty of clear explanations, tips, recommendations, pictures
Like for the Alula and Weasel, the first feeling is that everything is nicely designed to make the assembly easy ans straight forward, even for an average modeller.
- Tail + rudder: 17 gr
- fuselage 54 gr
- wing panels 2 x 51gr so 102gr
- accessories: 10gr
- sub total: 183 grs
Below is the photo album of the kit:
The video filmed last week-end
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