On Saturday, March 25, 2017 at 9:39:24 PM UTC-7, Bret Hess wrote: but I’d rather hear ideas from others.

Bret

Bret,

What was the rope made of?

Last year, after about 7 years of making the MKIV "high tech" yaw string, I made prototypes for what I thought would be the MKV. I am happy with the MKIV, but always looking to improve things. In this case, the advantage was eliminating the labor intensive "sandwich" construction of the MKIV, the V would be plastic welded to the base instead, as it used a slick round dacron cord rather than the more traditional yarn of he MKIV. I was unable to flight test the MKV due to a tractor accident, so sent a flight test sample to a friend as his MKIV was worn to a nub.

He sent back a short video showing the disappointing test results. The new yaw string wagged wildly like a happy dog's tail in about an 80 degree arc for 5 or 6 seconds, then froze to the canopy in a random position for maybe 3 or 4 seconds. FAIL!

My assumption is due to the "polished" smooth surface of the thin cord, there was minimal damping as there would be with "draggier" yarn. The cord set up a sort of positive feedback flutter while building static electricity that, when strong enough, was causing the freeze mode. Then when the static bled off, the cycle would repeat, over and over.

Wonder if that short length of rope would be doing something like that?

bumper
zz Minden
MKIV & QV