Don DeLoach wrote:
> Here’s an interesting comparison of the energy return of recent rubber
> batches. Tapio Linkosalo (Finnish F1B flyer) was the tester.
Hi Don! I'm here also. Been flying indoor for years, surrently F1M, but
working my way towards F1D...
> Look at 6/01! A notch above 5/99 and 2/99 in these tests. This confirms
> Larry Coslick’s flight test data of 6/01 from INAV a few years back. He
> tested ¼-motors in a low site on F1L and got the highest duration on 6/01.
I was somewhat worried that there was some error in the temperature
corrections. All my test have been conducted in room temperature, which
in wintertime (when I make 2/3 of my F1B motors for the Feb-Mar contest
season) is around 20C, while in summer it is more typically 25C. But,
having quite a lot of data I have calculated a temperature correction,
which indicates (assuming linear temperature dependency) 0.75% increase
per degree centigrade in the energy return (about the same figure for
both Tan II and SS). I checked my calculations, and found no error, so
it seems indeed that the Jun 2001 was the best batch. I think I had just
a pound or two of that, thus the good quality of that stuff remained
unknown to me, using motors from the 10lb box of May 99 for the flyoff
motors in F1B. Then, running out of better rubber I made a bunch of
motors from the 2001 stuff, just to find out that it was even better.
Whew! Have to check if I have any of it left... But I wonder if that
rubber was the one showing problems of splitting strands?
-Tapio-
Received on Wed Nov 19 2008 - 05:04:57 CET
This archive was generated by Yannick on Sat Dec 14 2019 - 19:13:45 CET