Archive of the Yahoo! Groups mailing list for the Bug hand-launch glider 2002-2018
From: "tom_yellowblue" <tom_yellowblue@...>
Date: Tuesday, May 27, 2003 11:40 AM
Subject: Re: On lightness, stretched wings and 1/8" CF tailbooms
John,
I can't remember the minimum voltage per cell, but I think it is in
the range of 2.5-3.0V. The manufacturers would have the info, and I
know it has been posted on the Ezone many times.
I've never had problem because I usually only use them in planes with
electric motors. On a 2-cell pack, the plane will be on the ground
before the minimum voltage is reached.
I have played around using a single cell for a glider, but I don't
have anything special for protection. I calculate about how long I
can fly before the voltage will get too low, then I give myself a
large margin.
I have also heard of people making/selling circuits that will light up
an LED when the voltage gets below a certain point. This may not help
if the plane is in the air for hours at a time, but it should work if
you're constantly hand-launching or can fly the plane close enough to
see the LED.
Tom
--- In BugHLG@yahoogroups.com, "gldrgidr" <gldrgidr@m...> wrote:
>
> I've heard that these cells are permanetly damaged if you let the
> charge go below something like 40%. How do you prevent this?
> John
From: "gldrgidr" <gldrgidr@...>
Date: Friday, May 23, 2003 9:47 PM
Subject: Re: On lightness, stretched wings and 1/8" CF tailbooms
I've heard that these cells are permanetly damaged if you let the
charge go below something like 40%. How do you prevent this?
John
--- In BugHLG@yahoogroups.com, "tom_yellowblue" <tom_yellowblue@y...>
wrote:
> gldrgidr,
>
> Bishop Power Products carries the 145mah Kokams. According to their
> web page it weighs .125oz (3.5g). Cost is $5.95. They also have a
> 560mAh version that weighs .424oz.
>
>
http://www.b-p-p.com/kokam145.htm
>
> Aircraft World (
http://www.aircraft-world.com/) has E-tech li-poly
> cells. The 250mAh version weighs 5.7g and costs $8.80 (shipping is
> only $2.50).
>
> I have had good service from both of these companies, but I haven't
> used these particular cells.
>
> Tom
>
> --- In BugHLG@yahoogroups.com, "gldrgidr" <gldrgidr@m...> wrote:
> > Where do you get the single 145mah Kokam and what does it weigh?
From: "tom_yellowblue" <tom_yellowblue@...>
Date: Monday, May 19, 2003 10:31 AM
Subject: Re: On lightness, stretched wings and 1/8" CF tailbooms
gldrgidr,
Bishop Power Products carries the 145mah Kokams. According to their
web page it weighs .125oz (3.5g). Cost is $5.95. They also have a
560mAh version that weighs .424oz.
http://www.b-p-p.com/kokam145.htm
Aircraft World (
http://www.aircraft-world.com/) has E-tech li-poly
cells. The 250mAh version weighs 5.7g and costs $8.80 (shipping is
only $2.50).
I have had good service from both of these companies, but I haven't
used these particular cells.
Tom
--- In BugHLG@yahoogroups.com, "gldrgidr" <gldrgidr@m...> wrote:
> Where do you get the single 145mah Kokam and what does it weigh?
From: "gldrgidr" <gldrgidr@...>
Date: Friday, May 16, 2003 9:08 PM
Subject: Re: On lightness, stretched wings and 1/8" CF tailbooms
Where do you get the single 145mah Kokam and what does it weigh?
--- In BugHLG@yahoogroups.com, "jason_wasylyk" <thetoothdoc@s...>
wrote:
> Hi John,
>
> Anyway, I'm building the stretch version with a single 145mAh Kokam
> for Rx juice so wing load should be down to <2oz/sq. foot. I'll
post
From: "bob_chiang2" <rhc3@...>
Date: Friday, May 16, 2003 3:11 PM
Subject: Re: On lightness, stretched wings and 1/8" CF tailbooms
--- In BugHLG@yahoogroups.com, "jason_wasylyk" <thetoothdoc@s...>
wrote:
> Hi John,
>
> I'm Zhack the author of the "Adding lightness..." article you
> mentioned. ...
>
> I'm by no means an accomplished HLG pilot and I rarely--in fact I'd
> say never--have a less than 2 minute flight in a typical session of
> 10 to 20 throws. I regularly speck(ed) her out (past tense owing to
> her tragic loss) and felt cheated if I didn't get in a five to 10
> minute flight every weekend.
>
> Anyway, I'm building the stretch version with a single 145mAh Kokam
> for Rx juice so wing load should be down to <2oz/sq. foot. I'll
post
> how this flies when it's ready.
>
> To sum up, the stock planform flies GREAT at low weight (see my
> article in the yahoo groups files section) and the stretched wing
> version can only be better. DON'T be afraid to use the 1/8" CF for
> the boom--just make sure you get the right stuff (see link above)
Hi Zhack,
I'm totally impressed (or maybe depressed). Through a full summer of
flying, I only had a handful of flights of over a minute (not
including sloping of course), and never specked it out from a hand
launch. I don't have a good scale, but my lace wing (in the photo
album) was built with light wood (borrowed a .1 gram scale to weigh
my balsa stock), little glue, relatively light covering, GWS pico
receiver and HS-50 servos. I do fly with a 110 mah 4 cell nicad pack
however.
I've been thinking of building another Bug and will take your advice
regarding the 1/8" tail boom and maybe extend the wing.
Thanks for the inspiration
Bob Chiang
Ithaca, NY USA
From: "jason_wasylyk" <thetoothdoc@...>
Date: Tuesday, May 13, 2003 11:05 PM
Subject: On lightness, stretched wings and 1/8" CF tailbooms
Hi John,
I'm Zhack the author of the "Adding lightness..." article you
mentioned. I've never had my BUG weigh over 3 oz with the original
wing area. It weighed about 75g when it got away. This has been a
very consistent thermaller for me at this weight. I've got nothing
but good things to say about this bird.
There seems to have been some controversy about the use of a 1/8"
tailboom in the yahoo group. From reading the 190 or so posts, it
seems that there is quite a variation in the stiffnees of
commercially available CF tube. The one I used is from CST:
http://www.cstsales.com/Carbon/carbon-rods.htm
These have been more than stiff enough for my hardest SAL/DLG. I use
the V-tail with no gyro (a little right rudder held with the left
thumb on the left stick during launch) and she launches arrow
straight. I have just enough time to recover my grip on the Tx and
push the nose over as she reaches her launch apex.
My full force launch is rarely over 30 feet because of the extremely
low (2.5 oz/sq. ft.) wingloading. Mind you at that weight, that's
all I need to find lift.
The same trade off between weight=launch height and
lightness="floatiness" seems to exist even at the highest eschelon
of this discipline (eg. the 11.5oz Full House Taboo competing with
the 9.5 oz composite poly owing to its higher launch as a result of
its greater mass).
I'm by no means an accomplished HLG pilot and I rarely--in fact I'd
say never--have a less than 2 minute flight in a typical session of
10 to 20 throws. I regularly speck(ed) her out (past tense owing to
her tragic loss) and felt cheated if I didn't get in a five to 10
minute flight every weekend.
Anyway, I'm building the stretch version with a single 145mAh Kokam
for Rx juice so wing load should be down to <2oz/sq. foot. I'll post
how this flies when it's ready.
To sum up, the stock planform flies GREAT at low weight (see my
article in the yahoo groups files section) and the stretched wing
version can only be better. DON'T be afraid to use the 1/8" CF for
the boom--just make sure you get the right stuff (see link above)