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21 foot Dunton Taylor Fast Climber project Goto page 1, 2, 3, 4, 5  Next
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KiteSquid
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PostPosted: Wed May 23, 2012 12:49 am    Post subject: 21 foot Dunton Taylor Fast Climber project Reply with quote

All,

I have been tasked with constructing, testing and flying a single line kite capable of lifting a spherical piece of "line laundry" to heights I have never flown to. I may have to go as high as 10,000 feet...

I am both excited and concerned.

I have scaled the plans up from the Richmond Air Force web page HERE

I have 40 yards of Icarex PC-31 for the sail and some heaver polyester for the leading edge sleeves.

I have some Kevlar for reinforcements

I even have a 1LB cone of Dabond Polyester V30 thread to sew it up.

There are some custom spar tubes being wound by Revolution but have not yet arrived.

As usual I have some things I might need help with:

I need to measure line pull. how do I do it on the line, not at the end of the line?

I need to calculate the aerodynamic drag of the line laundry, which will be a sphere, in different wind conditions. Who can supply me with the math or provide an MS Excel spreadsheet?

I need a small pulley for about 2mm line that can handle 200 Lbs and it needs to be all plastic....... no metal ball bearings or any metal parts. does anybody know where I can find one?

Can anybody explain to me how to calculate the properties of elastomers under tension? I am at a complete loss.

Oh I need to get the kite flying by the middle of next week... UGH
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KiteSquid AKA TakoIka AKA Harold of King George VA
PS Yet another post by the Squid... Shocked Doesn’t he ever shut up?
PPS The wind is like the air, only pushier.
PPPS All information provided is for hobby use. None may be used commercially.
PPPPS Vir sapit qui pauca loquitur. x11.5K
PPPPPS Please excuse my speling errorors.
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TBHinPhilly
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PostPosted: Wed May 23, 2012 11:41 am    Post subject: Reply with quote

Wow, that's quite a list ... for next week. Not sure but I will see if I can find a pulley that's small and all plastic. The rest is out of my wheelhouse.
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Ben
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Pumpkin



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PostPosted: Wed May 23, 2012 12:15 pm    Post subject: Reply with quote

Calculations for drag (force) on a sphere is here Twisted Evil
http://en.wikipedia.org/wiki/Drag_coefficient

not time to re arrange the formulas or run a spreadsheet at present but if no one else does I can sort one later tonight.

Why a line force guage in line not at end ???

Apart from localised transient conditions (like force from a gust affecting top of line before rest) the force in a line can be taken as even throughout.
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KiteSquid
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PostPosted: Wed May 23, 2012 12:22 pm    Post subject: Reply with quote

TBHinPhilly and Pumpkin, thanks for the feedback!!!!

Pumpkin wrote:
Why a line force guage in line not at end ???

Apart from localised transient conditions (like force from a gust affecting top of line before rest) the force in a line can be taken as even throughout.


Looking for gusts, and different wind forces at different altitudes.

And I don't want to exceed the breaking straight of the line, which for this testing will be low. about 300 Lbs.
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KiteSquid AKA TakoIka AKA Harold of King George VA
PS Yet another post by the Squid... Shocked Doesn’t he ever shut up?
PPS The wind is like the air, only pushier.
PPPS All information provided is for hobby use. None may be used commercially.
PPPPS Vir sapit qui pauca loquitur. x11.5K
PPPPPS Please excuse my speling errorors.
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KiteSquid
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PostPosted: Wed May 23, 2012 12:25 pm    Post subject: Reply with quote

I am now slowed down by the powers that be as now I also need to research a commercial off the shelf winch for it. there goes eight hours of production time.
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KiteSquid AKA TakoIka AKA Harold of King George VA
PS Yet another post by the Squid... Shocked Doesn’t he ever shut up?
PPS The wind is like the air, only pushier.
PPPS All information provided is for hobby use. None may be used commercially.
PPPPS Vir sapit qui pauca loquitur. x11.5K
PPPPPS Please excuse my speling errorors.
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MtnFlyer
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PostPosted: Wed May 23, 2012 1:15 pm    Post subject: Reply with quote

Hi Harold,

For the inline force measurement, how about this...

Two carabiners wrapped into the line as you would for laundry. Place them farther apart than the ends of the measuring device (for discussion say a spring scale). Attach the carabiners to the ends of the measuring device, creating slack in the line and allowing the measuring device to sense the force in the line.

You might have to expand on this idea if the forces are higher than what I'm thinking (more wraps around the 'biners, etc). Or the measuring device might be anchored to the ground with the line attached to the end with only one 'biner. Or...

Interesting and thought-provoking project.
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CJQ
Grand Champion, Kitebuilder of the Year 2006
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PostPosted: Wed May 23, 2012 1:43 pm    Post subject: Reply with quote

Concern about stress beyond line strength,,,, Kinda late to measure when the kite is up 10,000 feet. Wink)


CLIFF
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KiteSquid
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PostPosted: Wed May 23, 2012 2:20 pm    Post subject: Reply with quote

CJQ wrote:
Concern about stress beyond line strength,,,, Kinda late to measure when the kite is up 10,000 feet. Wink)


CLIFF


Kinda..... but if you let slack in the line you would mitigate the risk.... Until you ran out of line or airspace.
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KiteSquid AKA TakoIka AKA Harold of King George VA
PS Yet another post by the Squid... Shocked Doesn’t he ever shut up?
PPS The wind is like the air, only pushier.
PPPS All information provided is for hobby use. None may be used commercially.
PPPPS Vir sapit qui pauca loquitur. x11.5K
PPPPPS Please excuse my speling errorors.
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KiteSquid
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PostPosted: Wed May 23, 2012 2:21 pm    Post subject: Reply with quote

MtnFlyer wrote:
Hi Harold,

For the inline force measurement, how about this...

Two carabiners wrapped into the line as you would for laundry. Place them farther apart than the ends of the measuring device (for discussion say a spring scale). Attach the carabiners to the ends of the measuring device, creating slack in the line and allowing the measuring device to sense the force in the line.

You might have to expand on this idea if the forces are higher than what I'm thinking (more wraps around the 'biners, etc). Or the measuring device might be anchored to the ground with the line attached to the end with only one 'biner. Or...

Interesting and thought-provoking project.


good idea but I would probably use a Cat's Paw knot to attach to the carabiners.

Thanks for the thought.
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VR/
KiteSquid AKA TakoIka AKA Harold of King George VA
PS Yet another post by the Squid... Shocked Doesn’t he ever shut up?
PPS The wind is like the air, only pushier.
PPPS All information provided is for hobby use. None may be used commercially.
PPPPS Vir sapit qui pauca loquitur. x11.5K
PPPPPS Please excuse my speling errorors.
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CJQ
Grand Champion, Kitebuilder of the Year 2006
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Location: Coopersburg, PA - USA

PostPosted: Wed May 23, 2012 2:56 pm    Post subject: Reply with quote

Sounds like you need a tension measuring device not on the line but at the spool. How can you constantly monitor the load with line attachments as your feeding in either direction. Unless you had a deflection device with pulley's.

CLIFF
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TBHinPhilly
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PostPosted: Wed May 23, 2012 3:09 pm    Post subject: Reply with quote

How about this for a pulley? 3" long, 2" wide, 1 oz. Max rope diameter is 3/16" or 4.7mm. $19.99 + $5 SH. Not sure if that is a nylon bolt - but it is advertised as non-conductive.







http://antennapulleys.com/RP2.html
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Ben
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Doug LaRock
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PostPosted: Wed May 23, 2012 7:27 pm    Post subject: Reply with quote

Squid, I just built a running line pull gage for Bob Moore. It just what you need. I'll find the pictures and post them.

Doug
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TBHinPhilly
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PostPosted: Wed May 23, 2012 7:28 pm    Post subject: Reply with quote

Crowdsourcing on the kitebuilder forum. Gotta love it.
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Ben
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KiteSquid
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PostPosted: Wed May 23, 2012 8:22 pm    Post subject: Reply with quote

I found the sheaves HERE

Oh and I bought them at Grainger.com

Now to build the block...... I have a drill press so I think I need to buy some Forster bits and a block of Delrin or Nylon to machine it out of... I have a miter saw and a table saw to make the cuts.


Now to figure out what I need.......

WOO HOOO
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VR/
KiteSquid AKA TakoIka AKA Harold of King George VA
PS Yet another post by the Squid... Shocked Doesn’t he ever shut up?
PPS The wind is like the air, only pushier.
PPPS All information provided is for hobby use. None may be used commercially.
PPPPS Vir sapit qui pauca loquitur. x11.5K
PPPPPS Please excuse my speling errorors.
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CJQ
Grand Champion, Kitebuilder of the Year 2006
Grand Champion,  Kitebuilder of the Year 2006


Joined: 27 Dec 2003
Posts: 4601
Location: Coopersburg, PA - USA

PostPosted: Wed May 23, 2012 10:45 pm    Post subject: Reply with quote

Good find Ben, I'd spend the 20 bucks rather than trying to make one.


CLIFF
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TBHinPhilly
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PostPosted: Thu May 24, 2012 3:29 am    Post subject: Reply with quote

Apparently the beltway bandit is trying to help the Pentagon figure out how to make a $500 pulley. Twisted Evil
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Jesse Gersenson



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PostPosted: Thu May 24, 2012 7:51 am    Post subject: Reply with quote

If you're sewing an instrument pouch to the kite - remember to do it BEFORE the rest of the kite gets assembled. Embarassed And, double check you're sewing it onto the OUTSIDE of the box. Embarassed
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powder_pig
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PostPosted: Thu May 24, 2012 2:51 pm    Post subject: Reply with quote

Sounds like a REALLY interesting project. I hope you will keep us in the loop as it continues.
Inquiring minds... Laughing
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It's sunny and windy in the summer and cold and snowy in the winter...this must be what heaven is like.
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OldGoat



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PostPosted: Thu May 24, 2012 11:12 pm    Post subject: Reply with quote

What Ron said + I am really looking forward to seeing this project develop. Smile
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Doug LaRock
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PostPosted: Thu May 24, 2012 11:52 pm    Post subject: Reply with quote

Harold, here are some pictures of a running line pull gage I built for Bob Moore. If you want one I can design for what ever pull you want to measure. It can be mounted any where on the line near the winch and the line will run freely through it.





Doug
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