Re: 2008 so rules/ prop

From: leop12345 <leop_at_lyradev.com>
Date: Sat, 29 Sep 2007 20:41:44 -0000

Being a relative newcomer of just about a year's experience with indoor
flying and SO, I usually prefer to lurk around this group. After
conversing with many people including Bill Gowen and some SO National
Administrators, I have come to understand (?) the logic (?) and
interpretation of the current SO prop rules.

One piece ("a single, two-bladed commercially made plastic propeller"),
as they come from the manufacturer, props are allowed. Ikara props
come in one piece. The rules explicitly allow trimming to meet the
diameter rule and "trimming/shaving/twisting .... to balance and/or
reduce the mass of propeller or to change its pitch." It has been
explained to me that these modifications are allowed as long as the
prop stays in one piece as delivered from the manufacturer.

Although some would like to break and reglue the prop spars to change
the pitch, my students have found that repitching by heating the spars
works just fine (they use a mini heat gun or a hair drier with a size
reduced nozzle to heat the spars). Rather than continually repitching
one prop, the students just made several props with different pitches
for test flying ($15 for 5 props is not expensive compared to other SO
expenses). Last year, my students' best high site prop was an Ikara,
trimmed to the Bill Gowen Little Square profile and repitched to the
Little Square specified 1.4 P/D (thanks Bill).

Sometimes, I understand, an Ikara prop will break on impact, I have
been told that such breaks can be repaired. My students have repaired
cracks and crazings in repitched spars using CA glue. However, I have
been led to understand that it is pushing the rules to have complete
breaks on both spars.

Finally, these opinions are my own. When in doubt, it is easy to ask
for a rules clarification on the www.soinc.org site (but maybe not so
easy to get a clarification?).

Leo, Bloomington IN
Received on Sat Sep 29 2007 - 13:41:49 CEST

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