Earthstar Forums

Third 50 minute flight with the new cowl today. This time, I climbed out
for 3 minutes at 40kW; motor temp went from 63F to 169F, a 106F (59C) gain.
2 minutes at 15kW brought the temp back down to 142F. Later in the flight,
I climbed for 2 minutes at 40kW, which took the motor temp from 145 to
214F, a 79F (38C) gain. No signs of thermal management - should have kept
climbing. Climb rates between 600 and 800 fpm. On the way down, I saw as
much as 1.5kW regen.
It was still cold today (below 50F / 10C), and I will have to repeat these
test after it gets warm here, but for now, I can probably relax my focus on
temperatures.
I also moved my seat forward 1 notch. I was probably right at the aft CG
limit, and the Quark seemed to fly a little easier with this change. Still
plenty of elevator authority in all flight regimes, and I'll try another
notch further forward. Will also do more stall tests. I may have to
re-install some of the nose ballast. Earlier calculations showed that to
move the CG 1" forward, I would need to move the seat forward 3.5" or add 9
lbs of ballast in the nose.
Trim tab authority and adjustment range is sufficient (important backup if
a cable ever lets go).
Mark, I would love to do some tuft testing. But there is no convenient
place to see the tufts from the top - would require either air-to-air or a
camera. However, I think I would like to have one tuft at the base of the
windshield - the little ball in my GRT EFIS is easy to overlook. What is
the recommended material? I don't want to mess up the Lexan.

Martin, thanks for the info. I am hoping to pick up a salvage Zero SR 13.0 to start playing with a conversion myself. Nice to see how it is working out for you. I was somewhat surprised by the climb rate...would have expected higher with that setup. Am I missing something? Or just thinking wrongly? Both could easily be true...
Bob W

At 55 mph, it sure seemed steep. Not sure this is best climb speed, though.
And my setup is probably not optimized for climb (wing shape, prop pitch) -
I did not watch the motor rpm. I think I climbed faster with my previous
setup (30 kW motor, 90 lbs battery). The 110 lbs I gained with the larger
battery affect flying qualities in many ways. But I am really more
interested in maximizing range.

Anyone doing a Zero conversion on there own needs to contact me for details of what not to do!

Happy Flying,
Mark

Sent from our iPhone

Mark, if and when I am able to move forward with my project, it would be an honor to get your advice and warnings! Are you still using the Zero drivetrains are have you found something better? Inquiring minds want to know...
Bob W

Martin, I am with you. Would definitely sacrifice climb/top speed for longer flight time...
Bob W