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phil alvirez's blog
Archive for February, 2011
Posted by phil alvirez | Feb 26, 2011 @ 10:05 AM | 8,863 Views
Rondine (italian for swallow)-flying wing for um components
30"ws; 225 sq in; 60 grams auw.
on #1 wing, a 'black' motor, prop (5.1") and mount from 4site; on #2 wing, a p47 (with white motor and its prop-very much like the 5.1), both with 6400 brick. #1 had an extra servo at the beginning.
1mm foam for front (wrap around) and 2mm for rear. step at 50%.
elevons and rudder. the idea was to see how a wing does with rudder too, especially for indoor flying.
see more details here:
http://www.rcgroups.com/forums/showthread.php?t=1397047
i finished another with rudder further back, and have done a few test flights (miserable weather past 6 months and no more indoor) and seems promising.
may 7-tested today-see thread above for details. may 29: more tests: toe-in tips, and toe-in end plates, but rudder/fin removed. see thread....Continue Reading
Posted by phil alvirez | Feb 24, 2011 @ 03:39 PM | 8,214 Views
i began testing some motors for these planes:
tests on geared motors
i will post here figures on bench tests. i got the data using an e meter Mk I, that reads and saves figures on v/a/w/rpm's. volts are under load and no load. props used were horizon's 5.1 and 6.3, and gws 6/3 and 7/3.5. cells were hk 160 nano and 240 hyperion, charged to 90%.
> > > please notice that i got thrust figures with a tahmazo scale that measures on increments of 5 grams (like: 30, 35, 40...). this means that these figures should be seen as approximate rather than exact, as they could be let's say 49 and it's shown as 45...i don't know how it's programmed. someone may confirm or adjust this using the rest of the data with motocalc or similar. feel free to bring that data.
motors tested were coreless brushed 8.5 and brushless 10 mm. i named the 8.5 by color of rear cap (also called rear end bell):
clear is the original on sukhoi and champ; black on 4s/p51; grey is solo pro sp; white is bravo sx. p47 motor is same as bravo. pinions are 9 tooth.
figures were measured after 5 seconds run wot (wide open throttle) , once stabilized. i have been testing motors this way as a measure to prevent failures due to overloading anything, but they may drop considerably afterwards, when reaching the flat part of the discharge curve. some of the motor/prop/cell combinations can't handle wot, although can be used under less throttle settings or smaller props for normal flying.
data is shown to be...Continue Reading