phil alvirez's blog View Details
Archive for September, 2013
Posted by phil alvirez | Sep 12, 2013 @ 04:44 PM | 7,165 Views
finished the 2nd version of Thermalis, as i lost the 1st in the fog. changes include a more powerful motor, servos in the fin, and a little bit more tip dihedral. 30 grams heavier due to the new motor (see details of the Mk 1 on page 2 of this blog)
this time i covered the whole wing in red, instead of yellow tips of the 1st 1, to improve visibility, and covered the fuselage and stab white, and the rudder/fin black. canopy held in place with velcro, and some maple leaves in dayglo trim. they really glow at distance!
Thermalis is an idea of an electric sailplane for soaring in calm to moderate wind. it has 80" wingspan and 10" chord almost to the tip, and 764 sq in; now weighs 956 grams (33.5 oz) with a 3x1400 mah pack.
the concept: a simple sailplane for rudder and elevator-no ailerons, for relaxed flying and getting into thermals (hence the name), in moderate wind conditions. the wing is 1 piece polyhedral and the fuselage is box type, 1/8" solid balsa, like the horizontal tail and rudder. another feature that i added was the t tail, that improves the stability and makes the response more precise, as the stab is clear from the wing's wake.
am happy with the way the plane flies. very stable, and needs very little throttle. as a consequence the pack lasts longer. somehow flies different-but better. i believe that planes have personality, and when building the same, no matter how accurately you build it, each 1 behaves different.
oct 12, 2013: today i got back the mk 1 and am in the process of restoring it.
oct 21: ready and waiting for a window in the weather to try it.
Posted by phil alvirez | Sep 07, 2013 @ 05:44 AM | 6,199 Views
the idea is to see things as if i were in the plane; a pilot's view. not a film made with a camera to watch later.
and not to fly beyond eyesight. there are specialized forums for that, but it's is not my goal.
i did research and found the predator system from fat shark the most convenient. it has enough image quality and is complete. the only addition i made was the circular antenna set, as they are less prone to signal loss.
so far i have flown a plane with the predator: it's an exhilarating experience. mind boggling. you have to try it to fully understand the feeling, and once you do, you are hooked.
i have flown r/c for years, but you are watching the plane from a distance, and even if it is a great sensation, nothing compares to 'being there'.
from my brief experience i learned that:
1.-you need a spotter. always. that means, some1 near you to tell you if your plane is drifting too far, and/or where is it;
2.- google and print a plan of the area where you are going to fly;
3.-get the extra antenna.
i did none of the above and lost my plane. what happened was that i placed the transmitter antenna inside the fuselage along with it, so i got signal and then lost it-on and on-and i got disoriented.
as i did not have any1 to tell me where the plane was-or was heading-i had no idea where to steer it, and also no idea where i was.
with the stock antenna inside and along the fuselage, the things inside blocked the signal when i was turning.
if i had it outside and pointing upwards it could be way better, and even more with the circular antenna.
with a spotter i could bring back the plane. and if i had the map of the area i could find out where i was.
i did search the forums and asked questions about for instance where to place the components, but did not get any help.
but you now have my view and experience to save the aggravation. i hope this helps.
and welcome to the most fantastic experience!