GWTW Forum
July 05, 2015, 02:10 PM *
Welcome, Guest. Please login or register.
Did you miss your activation email?

Login with username, password and session length
News:
 
   Home   Help Forum Info Login Register Chat  
Welcome to the GWTW Forum.
Guests (non-registered users) can view the forum but are unable to post.  If you don't have anything to say then why would you bother to register?
One of the most popular sections of the GWTW Forum has long been the Swap Meet.  A great place to sell old, seldom flown kites or to get great deals on used (gently flown) kites.  Only registered users can see the Swap Meet section, let alone wheel and deal.  1000's (literally) of kites have changed hands thanks to the Swap Meet.
There are several more benefits to being a registered user, but you'll have to join our little community to find out all the "secrets".
Questions or concerns? Contact Steve ... just drop an email to: forum.gwtwkites@gmail.com

Pages: 1 ... 26 [27]   Go Down
  Print  
Author Topic: Doug Stout's Arrow Canard build (split off from the Stunt kite design tool)  (Read 63940 times)
0 Members and 1 Guest are viewing this topic.
Doug S
Trade Count: (0)
***
Offline Offline

Posts: 411


Location: Byram Township, New Jersey

« Reply #390 on: June 10, 2015, 08:52 PM »

Completed the testing of the 3 panel version of the Bird of Prey 36M, which is made from three different colors and weights of Cuben Fabric.  The "M" designation is for Multiple Panels.  The following provides the links to download the plans: 

Bird of Prey 36M Specification Plans (May 24, 2015):  https://drive.google.com/file/d/0Bwj9y_lTaMmFbDBrVDV4cWdhOFE/view?usp=sharing

Bird of Prey 36M Pattern Plans (May 24, 2015):  https://drive.google.com/file/d/0Bwj9y_lTaMmFeWF0UWVLdC14U2s/view?usp=sharing

If you access my Google Drive, these plans can be found there, along with various pictures of different areas of this completed glider kite.  A several of the pictures are provided below. 

The Bird of Prey 36M weighs 7.6 grams and balances where desired, without any additional nose weight, due to the heavier Cuben Fabric being used in the forward portion of the design, along with the associated glue and stitching.  Also, I am using a different FSD Nock (3 mm ID), which has a thicker wall and an OD of 6.3 mm.  It weights the same as the FSD 3.2 mm Nock glued inside the FSD 5 mm Nock.  With this single nock, one needs to extend the center spine to 20 3/4 inches.  These changes are noted on the Specification Plans.  This change in FSD Nocks also can be used for the standard single panel version of the Bird of Prey 36.

Performance wise, I love the way this glider kite looks in the air and handles on the flying line.  Its performance is on par with the standard single panel version of the Bird of Prey 36.

Yours in kiting,

Doug










« Last Edit: June 18, 2015, 02:10 PM by Doug S » Logged

"We never really grow up, we only learn how to act in public."
Doug S
Trade Count: (0)
***
Offline Offline

Posts: 411


Location: Byram Township, New Jersey

« Reply #391 on: June 10, 2015, 09:12 PM »

For the Bird of Prey 96, Tom White machined some great Wing Spar/Center Spine Joiners out of Delrin for me.  Tom and I have been dialing the correct angles (dihedral and forward sweep), and the new ones were perfect.  The following pictures show the new Delrin Joiner mounted in the lighter frame, along with it assembled in my front yard for flight.  Note how high the wing tips are off the ground, where the composite tubing joiner just was not stiff enough to maintain the desire dihedral unless the kite was in the air with the sail under load.  I also included a few pictures of me having fun with the Bird of Prey 96 with the new Delrin Joiner during the dusk hours in my front yard.  Sorry for the blurriness of the in-flight pictures.  Hard to fly this big glider kite with one hand and take pictures with the other hand.  These pictures also are on my Google Drive.  I believe I have this light frame configuration of the Bird of Prey 96 dialed in.  Will test the new Delrin Joiner with the heavier frame this weekend.

Yours in kiting,

Doug











« Last Edit: June 11, 2015, 09:23 PM by Doug S » Logged

"We never really grow up, we only learn how to act in public."
DavidformerlyDavid
Trade Count: (0)
**
Offline Offline

Posts: 48


Location: SF Bay Area

« Reply #392 on: June 10, 2015, 10:16 PM »

Hi, Doug!

  I'm intrigued by the new joiner.  You wrote that they were machined out of Delron, but might they also be 3D printed?  I'd love to get a Solidworks file for that dihedral and see what might be done with a printer.  If successful, this would be an easy thing to manufacture repeatably, and you could include the print file with your plans.

cheers,

David
(Happy BoP flyer)
Logged
Doug S
Trade Count: (0)
***
Offline Offline

Posts: 411


Location: Byram Township, New Jersey

« Reply #393 on: June 11, 2015, 10:51 AM »

David,

Thank you for your interest in this glider kite's joiner.  With my other Bird of Prey glider kites, I was able to find "off of the shelf" materials to construct each joiner that was stiff enough, but can flex just the right amount to obtain the desired flight characteristics.  This worked fine up to and including my Bird of Prey 62 with 862 square inches of projected sail area.  That all changed when I finished the Bird of Prey 96, with 2,079 square inches of project sail area.  There are various loads on the joiner, to allow the wing spars to have a slight "S" curve due to the desired tension on the cross line, while maintaining the desired 10 degrees of dihedral for each side, along with the swept forward angle to tension the sail appropriately.

Based on this, Tom White and I discussed making one out from Delrin.  I made the mistake of calling it Delron, but Tom corrected me and I have revised my prior posts with the correct name of this material.  Before Tom could finish the design of the Delrin Joiner, I needed to make a surrogate joiner out of "off of the shelf" materials that would set the wings spars at the correct angles.  The surrogate that worked was made from a composite of two types of tubing material, which set the correct angles and allowed me to measure those angles, to allow fabrication of the Delrin Joiner.  The Composite Tubing Joiner that worked was not stiff enough for any significant loads to the sail, such as from moderate winds or an aggressive climb.  It did work just fine for no wind/indoor flying conditions.  Since we are experimenting with two different frame (Skyshark P90s/Zero Airs and P100s/2PTs), the joiner angles are different for each frame because of the flexibility of each frame.  The Delrin Joiner is very stiff as compared to the Composite Tubing Joiner, so any flexibility needed to allow the Bird of Prey 96 to fly appropriately is done by using a mix of straight and tapered carbon wrapped tubes from Skyshark, as described above.  The tapered tubes are used in full length for the wing spars, from the cross line connection point to the wing tips.  A tapered tube in used in full length for the center spine, from the tail up through the location of the Joiner.

Using either the Composite Tubing Joiner or the machined Delrin Joiner, there are various forces acting on these joiners at various directions, due to the complex nature of this swept forward wing design.  Tom and I felt that we would need a quality material, such as Delrin, that would handle these forces acting at various directions, while having a smaller wall thickness, because the Delrin has a higher density than the composite tubing.

Based on your question about 3D printing, it's more likely that the 3D manufacturing technique will have a weakness in the plane of how the material is layered, and such material could split along this plane and cause a catastrophic failure of the joiner and damage the sail.  For now, we will continue with our development efforts using the Delrin.

With all of Tom's support and interest in the Bird of Prey 96, he has asked and I will build for him one just like mine in the near future.  I want to get this Bird of Prey 96 glider kite in his hands and get his input before I determine what the future availability and configuration of this glider kite will be for others.  It was not a quick build, but has been a very rewarding kite to design and fly.  Thank you again for your interest.

Yours in kiting,

Doug
« Last Edit: June 11, 2015, 11:02 AM by Doug S » Logged

"We never really grow up, we only learn how to act in public."
Doug S
Trade Count: (0)
***
Offline Offline

Posts: 411


Location: Byram Township, New Jersey

« Reply #394 on: June 18, 2015, 11:14 AM »

I made some minor edits to the ultra-light Bird of Prey 36 (single panel/color) glider plans, which show the single 3 mm FSD nock and the longer center spine (20 3/4 inches), which is needed for this FSD nock.  I also uploaded to my Google Drive the plans for the Bird of Prey 36B, which is the same pattern as the standard Bird of Prey 36, but uses the slightly heavier blue Cuben fabric.  "B" stands for the second version of this model and the blue color of the fabric.  The direct link to the Bird of Prey 36B plans are provided below:

Bird of Prey 36B Specification Plan (June 15, 2015)https://drive.google.com/file/d/0Bwj9y_lTaMmFcmVNSGxidGktdUU/view?usp=sharing

Bird of Prey 36B Template Plan (June 15, 2015)https://drive.google.com/file/d/0Bwj9y_lTaMmFRTZMeXBUakdydDg/view?usp=sharing 

At the suggestion of other glider kite enthusiasts, I started a new post so one has easy and direct access to my Google Drive, without having to move through the numerous pages of this discussion thread.  This will make it easy to others to find the links.   I added a new folder that contains pictures of Bird of Prey glider kites built by others, such as Tom White.  The plans and pictures indicated above are provided in the appropriate folders on my Google Drive.  Enjoy!  Grin

Yours in kiting,

Doug
« Last Edit: June 18, 2015, 02:13 PM by Doug S » Logged

"We never really grow up, we only learn how to act in public."
Doug S
Trade Count: (0)
***
Offline Offline

Posts: 411


Location: Byram Township, New Jersey

« Reply #395 on: June 27, 2015, 07:27 AM »

Weather was just right the other night.  Took the Bird of Prey 36M our for a flight in my front yard.  I do love this glider kite.

Doug

Logged

"We never really grow up, we only learn how to act in public."
Doug S
Trade Count: (0)
***
Offline Offline

Posts: 411


Location: Byram Township, New Jersey

« Reply #396 on: June 27, 2015, 10:34 AM »

With the new machined wing spar/center spine joiner, I wanted to let the Bird of Prey 96 sit assembled hanging in my basement for at least a week to see how much the 170 pound spectra/Dacron covered cross line would stretch out.  It only stretched about 3/32 of an inch, which lowered the dihedral by about 1.5 inches.  Even with the lighter frame  (Skyshark P90s/Zero Airs), there is a bit of tension on this cross line, which is what I wanted as the result of the angles Tom and I used for the machined joiner.  This tension keeps the frame stiff between the connection points of the cross line, so when the sail is under load, the tips will flex and washout as desired.  The length of the cross line on the Bird of Prey glider kites is very sensitive to minor adjustments.  I re-adjusted the cross line knot location to obtain the desired 16.5 inches (20 degrees) of dihedral and we are set to finish my test flying.

The Bird of Prey 96 with the lighter frame (Skyshark P90s/Zero Airs) and the new wing spar/center spine joiner weights 145.2 grams, which includes 20 grams of nose weight for the 3.5 inches of 6 mm OD stainless steel rod to obtain the desired location for the center of gravity.  As an unanticipated benefit, it appears this concentrated mass of nose weight is acting like the tail weight in stunt kites, which helps me spin this glider kite around in tight circles above my head.  At 145.2 grams, this provides a sail loading of 0.0699 grams/sq.in. of projected sail area of 2,079 square inches.  For your information, the total sail area before assembly is 2,113 square inches.  This sail loading is in line with and lighter than my other conventional eight foot glider kites with six sail panels.  The center of gravity is 21.625 inches behind the nose of the sail, which provides a static margin of 2.2%, which is the sweet spot for my Bird of Prey 48 and 62.  Now if mother nature would cooperate (itís raining again in the northeast), the Bird of Prey 96 is ready for one last set of test flights in a large open field under no/low wind conditions.  During the next step of testing, I also will install and test the Bird of Prey 96 with the heavier frame (Skyshark P100s/2PTs).  Next week, I will start building the one just like mine for Tom White.

In the future, I may look into reducing and adjusting the number of panels and the associated seams behind the center of gravity, so that I can in turn reduce the 20 grams of nose weight to achieve the desired center of gravity.  These refinements would allow me to reduce the overall sail loading of this large glider kite.  As a point of reference, the Bird of Prey 96 with the 16 double stitched panels has a lower sail loading by about 9% than the HQ Hybrid 240 (estimated to be 0.0763 grams/sq.in), but has a higher sail loading by about 16% than Horvath's The Long Way Home (estimated to be 0.0590 grams/sq.in.).

Since the glide slope on the Bird of Prey glider kites is extremely flat, the reduction of total weight may not be desired for this size glider kite with a mean wing chord of 21.66 inches.  What we have found for outdoor flying the higher sail loadings help the Bird of Prey glider kites penetrate turbulent air and glide more efficiently, where the larger lower sail loading Bird of Prey glider kites, such as the Bird of Prey 48 made with Cuben fabric, stop forward movement and park when encountering turbulent air.  Just my thoughts while I continue to experiment with this large beautiful glider kite, but I am a little biased.  Grin

Later,

Doug
« Last Edit: June 27, 2015, 10:50 AM by Doug S » Logged

"We never really grow up, we only learn how to act in public."
DD
Trade Count: (+16)
*****
Offline Offline

Posts: 1024


Location: Ohio USA

« Reply #397 on: June 28, 2015, 08:08 AM »

Could you get away with not sewing at all but using 3m tape?
Logged

Sine Metu!
Doug S
Trade Count: (0)
***
Offline Offline

Posts: 411


Location: Byram Township, New Jersey

« Reply #398 on: June 29, 2015, 08:01 AM »

DD,

Thank you for your suggestion.  I built the prototype of the Bird of Prey 96 with straight panels where I prefer to use a Plan Seam.  This is how I use to build my stunt kites and it's a very strong seam.  This seam has an extra layer of sail material along the seam, along with the additional row of stitching.  My goal with the prototype of the Bird of Prey 96 was to see how it also could handle higher wind conditions, so this construction technique was appropriate.  I have flown the Bird of Prey 96 in winds up to 15 mph and it does just fine, but does have a bit of pull on the flying line during the climb.  Considering the 2,079 square inches of projected sail area, the pull on the flying line during a climb in the higher wind conditions was expected.

I also could use a Lap Seam that only requires one line of stitching.  This is the technique I use on the Bird of Prey glider kites that have the curved panel lines.  I prefer using a glue stick to hold the panels together before stitching, which gives one a second chance to adjust the alignment if you don't have the panels aligned correctly.  Regarding your suggestion to use just double sided tape, I have found that under higher temperatures and moderate wind conditions, the adhesive will give and the panels will slip.  I have experienced this with some glider kites designed/build by others.

As a point of reference, the prototype of the Bird of Prey 48 was built with 12 panels using a Plain Seam and weighs 31.8 grams.  The plan/production version of the Bird of Prey 48 was built with just 5 curved panels using a Lap Seam and weighs 30.7 grams, providing a weight savings of about 3.5%.   If I apply this weight savings to the Bird of Prey 96, I would be able to reduce the weight of this glider kite by approximately 5 grams.  Since most of the Bird of Prey glider kites need some nose weight, if I reduce the number of panels behind the center of gravity, this also will help save some weight.

If one was looking for the lightest version of the Bird of Prey 96, the least amount of panels/colors would be the way to go, but I personally like the looks of this glider kite in the air.  As indicated in my previous post, my limited flying time on this glider kite indicates that lighter may not be the way to go.  That is why I want to get a second one in Tom White's hands on the west coast to see if he sees what I am seeing.  When I test flew the Bird of Prey 96 indoors at the Wildwood NJ event, it flew very well.  This was before I had the stiffer machined joiner and the center of gravity dial in.  It was a just a little tail heavy when I flew it in Wildwood, NJ.  Thank you again and I will keep you posted on my future endeavors with this version of my Bird of Prey.

Doug
Logged

"We never really grow up, we only learn how to act in public."
DD
Trade Count: (+16)
*****
Offline Offline

Posts: 1024


Location: Ohio USA

« Reply #399 on: June 29, 2015, 08:51 AM »

Doug,
 Are you talking the 3m tape(which i cant find a name or a number on at the moment) I have never seen that tape fail or move and was told by a prominent builder that he considered not using stitching but just the tape. I told him "no way" and after setting some fabric up with it he challenged me to get it apart. The fabric failed before the tape.
Love all  of your discussions, keep up the good work!
Logged

Sine Metu!
Revrookie
Trade Count: (0)
*
Offline Offline

Posts: 11

Location: Calgary Alberta Canada

« Reply #400 on: June 29, 2015, 09:19 AM »

9460 VHB tape made by 3M and a hot iron to fuse it forever - Paul LaMasters on KiteLife.

It seems the ironing causes the final fusion that makes it permanent.

Kelly
Logged
Doug S
Trade Count: (0)
***
Offline Offline

Posts: 411


Location: Byram Township, New Jersey

« Reply #401 on: June 30, 2015, 07:44 AM »

DD and Revrookie,

For double sided tape and at the recommendation of others on this forum, I have been using various widths of the 3M 924 Non-Acid Free ATG tape from framingsupplies.com.  As indicated in my prior post, my experience for Lap Seams has been better with an Elmer's Glue Stick and stitching, following Sugerbaker's assembly process.  Thank you for the suggestion and I will look into the 3M 9460 tape.

One should keep in mind the weight of the tape/glue as compared to stitching.  Recently I build a three panel version of my ultra-light Bird of Prey 36 using Cubin Fabric and was pleasantly surprised how little weight the glue stick/stitching assembly technique added to the overall weight of this glider kite.

Doug
Logged

"We never really grow up, we only learn how to act in public."
nckiter
Trade Count: (+1)
**
Offline Offline

Posts: 78


Location: North Carolina US

« Reply #402 on: June 30, 2015, 11:33 AM »

Hi Doug,
Been following your design and build process all along. Great stuff, nice looking birds, hope to try one out one day.

The 924 is a great tape in it's own right and similar to the 9460 in that they are both adhesive transfer products, that is there is no carrier scrim left after you peel off the backing, just pure adhesive. They are both acrylic adhesives but different formulas. I find the 924 gums my machine needles far more that the 9460. The 9460 is a VHB (very high bond) adhesive and will give "permanent" bonds. You've found the right place to get the 924, for the 9460 try Tape Case.

 http://www.tapecase.com/pd/cn/tapes-die-cuts/1024/1000694/3m-f9460pc-vhb-adhesive-transfer-tape.aspx

I have bought it from them in widths from 1/8" to 3/8".
« Last Edit: June 30, 2015, 11:51 AM by nckiter » Logged
Pages: 1 ... 26 [27]   Go Up
  Print  
 
Jump to:  


Kite Classifieds Ad
Kite Classifieds

A Wind Of Change
A Wind Of Change

Untitled Document
Untitled Document

FMKS
Fly Market

Smooth Winds
Smooth Winds

A Wind Of Change
skyshark

Kitebookie
Kitebookie.com

Untitled Document

Untitled Document
Untitled Document

Our forum is made possible by the good folks whose ads appear above and by the members of our community (PayPal donation button at bottom)
In case you missed it each ad is linked to the sponsors web site.  So please, take a moment and visit our sponsors sites as this forum wouldn't be possible with out them.
Interested in running an ad for your business or kiting event?  Contact Steve at advertise.gwtwkites@gmail.com for a quote.

Cal Custom

Support the GWTW Forum

Powered by MySQL Powered by PHP Powered by SMF 1.1.8 | SMF © 2006-2008, Simple Machines LLC
SimplePortal 2.2.1 © 2008-2009
Valid XHTML 1.0! Valid CSS!