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From: ykleetx <ykleetx_at_gmail.com>
To: Indoor_Construction_at_yahoogroups.com
Sent: Mon, November 29, 2010 4:25:53 PM
Subject: [Indoor_Construction] EZB motor stick
Larry.
On you recods flight give an account of the flight
Yang
First of all, I don’t mess with ¼ motor flights in ceilings over 100’ I prefer
½ motor or ¾ motors flights and have found that quarter motor flights don’t
equate to full motor flights in high ceillings. Quarter motor flights usually
fly in the cooler ground air while ½ motor flights and get the benefit of the
warmer upper air.
35:01 flight at lakehursr, 2007
The second or third ½ motor flights did 17:30 at an altitude of around 75’. I
used a rather small symmetrical prop of 11.8” and a pitch of 19. The motor was
5/99 .024x13 and weighed.36 gram. I wound in 3330 turns to a torque of.09 and
backed off 90 and loaded the motor at .53 inch ounces. These light models need
to be launched at a rather steep angle to keep the outboard wing from tucking
under. The model climbed rather close to the ceiling but I don’t have any
records of how long it staved there. I do remember that its let down time
was quite long. The model landed with 310 turns and that was the only official
flight that I made with that model that day. I had two other records to shoot
for the next day..
For new indoor fliers don’t get carried away with building super light models.
I usually spend a full day in selecting the wood for lightness and stiffness
that is to be used in my next model. There’s so much more information on
building and flying indoor models today than when I started 19 years ago.
My first 30:00 EZB in 1993 weighed .83 gram and #34 did 34:00 at Akron and
weighed .55 gram and that model did a no touch flight of 30:41 at Johnson City.
Larry Cailliau did 35+ at Tustin in the late 90’s and I can’t remember why that
flight was declared unofficial , I believe that his model weighed over .5 grams.
Larry C
Hi, Larry, Max,
Good to hear from you guys.
The 6" 67 mg motor stick is originally part of a lighter 310 mg EZB. Max, if you
recall, I had brought it to Lakehurst over Labor Day weekend. As it turned out,
I switched the wing and prop from a heavier EZB, so that the total weight
increased to 370 mg. That is how it appears in the INAV plan. For a 370 mg EZB,
I would also put a little more heft into the motor stick.
Keep in mind that the 30 minute flight at Lakehurst was one of its first flights
and not yet trimmed perfect. It's difficult to determine what is its full
potential. I believe on a good day at Lakehurst, 33+ is possible. We will see
how it flies next summer at the hangar.
I decided on a short motor stick because I thought it would better guard against
motor stick bowing and twist, compared to a 7 or 8" stick of similar density and
stiffness. At the same time, I can lose a few 10's mg.
So far, I see that my light motor stick, even though it is only 6", is sensitive
to the tension and twist of the motor. I have to back off about 150 turns and
launch at .08 to .09 in-oz. But this is still a very large amount of torque and
more than enough to take the model to the top of Lakehurst and higher.
For me, all of this is part of an ongoing experiment. My newest EZB weighs 310
mg and has a 62 mg 6" motor stick. Again, perhaps the stick is too short and too
light. I just don't know and will do my best to experiment and find out.
I know that Larry has written that a longer motor stick is needed for a long
cruise. I have the utmost respect for Larry and have learned a lot from his
articles. I find it interesting to experiment and try new things, and I will
report my findings as I learn them.
Max,
Can you send me a copy of your 320 mg EZB plan? I would love to see it.
Larry,
On your ?
record flight, can you describe the flight profile? Time to climb, maximum
altitude, cruise and descent times
Thank you.
-Kang
Received on Mon Nov 29 2010 - 17:58:21 CET
This archive was generated by Yannick on Sat Dec 14 2019 - 19:13:46 CET