On Mon, 26 Feb 2007, Fred Tellier wrote:
> What was strange was the turns and maximum torque were not that
> different but the foot pounds per pound value was down. I did not run
> enough tests to create the kind of data that Garry would like to have
> but the results were definitely there. I always wanted to do the same
> tests at 30 deg C but never got around to it, and the only rubber I used
> was 5-99 as it is all I use in competitions.
This agrees with my results flying outdoors. Even in the freezing
temperatures you get the same maximum torque into the rubber (of course
winding will warm to rubber some, so this may also have some effect), but
then during the climb you can really tell that the cruise torque is lower
than in the warm. Actually, in the heat of the summer the rubber tends to
get softer and break more easily, and under lower torque, so on the
hottests days I tend to use slightly lower maximum torque to aim for.
During the day it is not that essential after all, as during thermal
activity you either hit or miss the good air anyway.
This has some interesting consequences for indoor flying: you can no
longer predict the cruise torque from the maximum torque that you get to
the rubber, but in the cold the drop from maximum to cruise is higher, and
you need to go to a thicker cross-section for the same cruise torque...
> By the way Tapio, how is your F1M flying these days and did you get your
> VPs working?
I have one VP that is working quite well, and have been flying at about
the same level as I did in USIC and West Baden. Under lower ceiling my
times are not that good, something around 12 minutes in Cat I, so I should
get the VP a bit better. I still somewhat struggle with the weights and
structure for it though. Would prefer using some metal or carbon parts to
make the unit easier to reproduce, as all balsa construction seems so
"every unit is unique" approach to me, but not much success there. I even
built my first F1D last autumn, way too heavy and the motor tube collapsed
once I started to get some idea of the trimming. At the moment I'm busy
with contest season on F1B, peaking with the World Champs at the end of
June, but I plan to do some indoor duration stuff again during the latter
part of the year, including another F1D. I hope some day I'm good enough
to travel with my models to some champs or to another USIC. At the moment
my skills are not good enough to justify such a trip.
-Tapio-
Received on Tue Feb 27 2007 - 00:46:47 CET
This archive was generated by Yannick on Sat Dec 14 2019 - 19:13:44 CET