Monday, May 23, 2016

Flying the Weasel TREK !


The maiden flight happened on a south slope by a sunny weather, but when I arrived at the top, the wind was more from west, and very weak. I moved to the west side of the slope where the slope angle is almost flat. Anyway, I could test the Weasel in pure thermal flight conditions and have been very positively suprised. From the first launch, she flew like a charm, no trim needed, recommended settings are perfect. Despite the light weight of 290gr, she has a better lift-to-drag ratio and penetrates better thanks to the combination of the light weight and lower camber of the airfoil, so I could fly very far, transition from one thermal to another very easily, cover lot of distance, like I was piloting a larger sailplane. During the afternoon, I did some very good gain of altitude starting from very low and finishing at 100 to 150m few minutes after. It is true that weasel is desmontrative and indicate clearly the lift which make the thermal hunting easier. In addition, the finger hole at the bottom of the skid provides a very good grip and allow to launch very strongly which help in small conditions. The lift-to-drag ratio is very noticeable with the ground effect when you land and can surprisingly cover a longer distance than expected.


In higher wind condition, the Weasel TREK shows her DNA and wilder temperament. Here again the low camber section provides a better speed range, in all situations. Nose and control surface weight reduction improve the pitch response, so give more manoeuvrability. Same on the roll axis with a crisper response. As you can guess from this, aerobatic capabilities are therefore very good, with much easier and effortless inverted flight, more axial rolls and step rolls, loopings , reversal. But also all these improvements make the Weasel TREK easier to fly VTRP (aerobatics close to the ground), helped with her compact size. In top of this, I found her to have a much better energy retention, in turn and also for vertical manoeuvers, despite her light weight. This is a very good characteristic, which is not easy to obtain ! She carries the 50gr ballast easily but could carry much more weight when the wind is above 10+ m/s.

Finally this new Weasel TREK is a "boosted" and "over vitamined" Weasel version with a wider flying envelop from low conditions to medium breeze, more agile, faster, more aerobatic and provide the same amount of fun and adrenalin whatever the lift ! The Weasel remains definitively one of my favorite slope glider !

and a video filmed the same day:


Friday, May 20, 2016

Weasel TREK: Light speed assembly !



In fact we cannot really talk about assembly as it takes 25 minutes to have it ready, no glue is needed. This is faster than some RTF kit.

The work consists mainly in


  • installing the 2 servos in their location, servo arm at the neutral position. I use some UHU glue to secure, but this is not necessary, there are 2 transparent tape pieces to cover and maintain in place the servos.
  • route the servo wires to the radio compartiment
  • tape the velcro on the nose and on the battery to secure it
  • install the plastic clevises on the control rods.
  • install the 2 screws on the joiner lock system (same as the Alula TREK)
  • No lead needed in the nose for the CG balancing, I even had to move back the battery by 5mm.

If you want some colors, acrylic paint in spray will do it easily. I used some masking paper tape. This is clearly longer than the assembly itself, but she deserves it !

On the balance, she weights 290grs vs the 330grs of the Weasel Black Edition. Additional ballast is about 50gr, perfectly centered on the recommended CoG.



Monday, May 2, 2016

Weasel TREK: Kit Overview

I just received one of the very first kit of the Weasel TREK. She arrived in a very nice orange box, that will be much more convenient to carry it.
This new weasel seems very similar in term of planform, but probably has different airfoils. The visible differences are:


  • Elevons are moulded, not balsa. they seems stiff enough when I manipulate them.
  • Like the Alula TREK, she has a canopy giving a full access to the radio compartiment and a plastic landing skid to protect the underside of the nose. the canopy is maintained in place by several magnets.
  • The spar is no more integrated during the moulding, but added/glued after.
  • The locking system is the same than the Alula TREK, and the joiner too.
  • The skid integrate a ballast compartiment able to receive 50g of lead. It also keep the finger recess for better launching
  • The fin is secured with a magnet.



In term of construction, spars, control horns, magnets, skid are all in place, which means a speedy assembly, around 30 minutes like the Alula TREK. The longer will be once again to decide about the color scheme and the painting :) ! I have few hours to think about it before to start the assembly.

Quality of the moulding and fit is as good as the Alula TREK, with a nice surface finish.

As option I received also the 750mAh NiMh battery and the 2 metal gears servos (12gr class servos), and the lead extension between the receiver and the battery.

The weight of the frame + radio equipment is 280grs, compared to the 360grs of my Weasel EVO (made from EPP). Light flying weight means better capabilities in light conditions, and better agility. I anticipate the Weasel TREK to be a nice aerobat, VTPR capable.

Specifications:
  • Wingspan: 900 mm (35.4 in)
  • Wing Area: 23.42 dm2 (363 in2)
  • Weight: 312-395 gm (11.5-14 oz)
  • Wing Loading: 13.3-16.9 gm/dm2 (4.6-5.6 oz/ft2)
  • Controls : 2 Channels (elevons)
  • Assembly: Under an hour (I would say 30 minutes)
  • Flight Style: Slope thruster
  • Wind Speed: 3-12 m/s (7-25 mph)
I'm very exited to test this new Weasel TREK as I really loved the previous versions. I had one Weasel EVO EPP in 2009, and I still have my Weasel Black Edition, so it will be an opportunity to test them side by side. Stay tuned for the assembly and the maiden that should happen this week-end !

Mistral Soaring - Rognac

Yesterday we had a good friendly winter contest in Rognac, between Aix en Provence and Marseille. I left Grenoble aroudn 7am under the sn...