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wdrwilson
Joined: 25 Oct 2003
Posts: 1688
Location: Canada, Nova Scotia, Halifax
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 Posted: Thu Jan 29, 2009 12:10 am Post subject: |
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| flyingscot wrote: | Bill
You talk about the stiffness and weight of the P200 . Would any of the spars below be anywhere near the P200 or P300?
I have a lot of spars on hand that I got from a kite store that was going out of business. I really have no idea what their differences are. The bulk are: Glaspar A20 thru J65; Aviasport .220, .230 & .240; and Beman ProComp 16 and <a href="http://www.kitebuilder.com/catalog/index.php?cPath=33">Carbon</a> Strong 16. All are 32.5" spars.
I would like to use some of these spars in place of the Sky Shark spars for the Fled, unless they would drastically alter the kite's performance.
Any thoughts would be appreciated.
Elmon Morrison |
Hi Elmon,
I haven't actually used any of the spars you have listed with the exception of the Aviasport tubes. So I am probably not the best to ask on this one.
There is an interesting table here http://www.nic.fi/~sos/spars/spars98.htm that could help determining relative stiffness, etc. It was put together some time ago (11 years) but it should give you some more info.
I would say that the .2400 should be ok for the spreader, but it might be a bit light. perhaps an 8mm spar would be better.
the .2200/.2400 should be good for the longerons.
What do some of the other folks that have experience with these spars think??
It might also be looking at the Rok spar guidelines here...
http://www.kitebuilder.com/techsheets/rokkaku.htm
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Bill Wilson
www.steadywinds.com
Imagination is the highest kite one can fly. - Lauren Bacall |
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Fore Check
Kite and Kitebuilder of the Year 2009
Joined: 15 Jun 2008
Posts: 2649
Location: The Montessori School of Kites (near Findlay, OH)
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| Posted: Thu Jan 29, 2009 2:05 am Post subject: |
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Looking at the spar charts (and not any personal notes - so take it for what's worth)
The J65 would be pretty darn close to the P200.
Don't know about those Beman rods; I was trying to glean some relevant information from the original David Lord chart and there are like 4 or 5 different references. To Beman Carbon Strong, Beman Strong Carbon, and mix up those words and spellings a few more ways.
As Bill suggests, I would go with something stronger than what you currently have for the spreader (not knowing what the Beman rods are)
8mm Carbon is a good choice if you don't want to use SSP300.
---
I'm an addict, I think. I've picked out the colors for my next Fled. 
I'll just have to play "catch up" after Steve ships me the fabric. 
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Discovering Something that Doesn't Exist...
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wdrwilson
Joined: 25 Oct 2003
Posts: 1688
Location: Canada, Nova Scotia, Halifax
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| Posted: Thu Jan 29, 2009 2:35 am Post subject: |
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Only a couple of more days... 
I just finished getting the first post ready, I will have it up Friday morning.
I am really looking forward to the discussion, there has been so much chatter about this kite over the last little while it will be nice to see the different variations (H.A.R, diapers, you name it)
Cheers,
Bill
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Bill Wilson
www.steadywinds.com
Imagination is the highest kite one can fly. - Lauren Bacall |
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KiteSquid
Master Kite Builder
Joined: 29 Aug 2003
Posts: 10131
Location: USA Virginia King George
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| Posted: Thu Jan 29, 2009 2:42 pm Post subject: |
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| flyingscot wrote: | You talk about the stiffness and weight of the P200 . Would any of the spars below be anywhere near the P200 or P300?
I have a lot of spars on hand that I got from a kite store that was going out of business. I really have no idea what their differences are. The bulk are: Glaspar A20 thru J65; |
I don't have much experience with these tubes, so I cannot comment.
| flyingscot wrote: | | Aviasport .220, .230 & .240; |
Pultruded tubes. I would use the 0.240 as ferruling material for SS tubes.
| flyingscot wrote: | | and Beman ProComp 16 and Carbon Strong 16. All are 32.5" spars. |
these are the closets in performance to the SS Tubes are these are also arrow blank seconds.
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KiteSquid
AKA TakoIka
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King George VA
PS Yet another post by the Squid...  Doesn’t he ever shut up?
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PPPS All information provided is for hobby use. None may be used commercially.
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PPPPPS Please excuse my speling errorors. |
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Spence602
Joined: 16 Sep 2003
Posts: 1420
Location: USA TX Houston
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Fore Check
Kite and Kitebuilder of the Year 2009
Joined: 15 Jun 2008
Posts: 2649
Location: The Montessori School of Kites (near Findlay, OH)
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| Posted: Fri Jan 30, 2009 12:02 am Post subject: |
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I've found mikenchico's spar spreadsheet to far and away the most helpful...
http://www.sysmatrix.net/~mikenchico/Spar_Deflection.xls
...with a tweak.
I added a cell at the top to "paste" the deflection value of any spar in the chart into.
Then I added columns for "relative stiffness" and "scale factor" - based on the method for determining those values used by David Lord in his original spar chart (linked to by Spence.)
Just FYI: "relative stiffness" for a spar is a that spar's deflection value, divided by the deflection value of the spar your comparing it to.
"Scale factor" is the fourth-root of the "relative stiffness." This is easily set up in a spreadsheet as = "relative stiffness" ^ (0.25)
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Simon
Discovering Something that Doesn't Exist...
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wdrwilson
Joined: 25 Oct 2003
Posts: 1688
Location: Canada, Nova Scotia, Halifax
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| Posted: Fri Jan 30, 2009 12:12 am Post subject: |
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Hi Fore Check,
I like that spreadsheet... thanks a lot!
That should really help folks who are using different spars for this build..
Cheers,
Bill
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Bill Wilson
www.steadywinds.com
Imagination is the highest kite one can fly. - Lauren Bacall |
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Fore Check
Kite and Kitebuilder of the Year 2009
Joined: 15 Jun 2008
Posts: 2649
Location: The Montessori School of Kites (near Findlay, OH)
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| Posted: Fri Jan 30, 2009 12:38 am Post subject: |
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| wdrwilson wrote: | Hi Fore Check,
I like that spreadsheet... thanks a lot!
That should really help folks who are using different spars for this build..
Cheers,
Bill |
Mikenchico gets all the credit; he originally posted it here:
http://www.kitebuilder.com/forums/viewtopic.php?t=6022
...as the 8th post in that thread, near the bottom of the 1st page.
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Simon
Discovering Something that Doesn't Exist...
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wdrwilson
Joined: 25 Oct 2003
Posts: 1688
Location: Canada, Nova Scotia, Halifax
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| Posted: Fri Jan 30, 2009 2:25 am Post subject: |
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| Fore Check wrote: | | wdrwilson wrote: | Hi Fore Check,
I like that spreadsheet... thanks a lot!
That should really help folks who are using different spars for this build..
Cheers,
Bill |
Mikenchico gets all the credit; he originally posted it here:
http://www.kitebuilder.com/forums/viewtopic.php?t=6022
...as the 8th post in that thread, near the bottom of the 1st page. |
I couldn't resist..
I added the Relative Stiffness and Scale Factor Columns. At the bottom of the sheet you can choose the reference spar from a drop down list of all spars in the chart.
I also added a little spar to spar comparison formula at the bottom as well. Select a ref spar and a comparison spar from the drop down lists to see the relative stiffness and scale factor.
I am not an excel expert, so I am sure there are other ways to do what I did..
www.steadywinds.com/plans/Spar_Deflection_Steadywinds.xls
Hope this helps people pick the right spars ..
Cheers,
Bill
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Bill Wilson
www.steadywinds.com
Imagination is the highest kite one can fly. - Lauren Bacall |
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Fore Check
Kite and Kitebuilder of the Year 2009
Joined: 15 Jun 2008
Posts: 2649
Location: The Montessori School of Kites (near Findlay, OH)
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| Posted: Fri Jan 30, 2009 10:03 am Post subject: |
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There ya go!
I set my changes up a little differently, but it's the same basic idea.
I find myself referring to this spreadsheet *a lot* - particularly with the relative stiffness and the scale factor added to it.
I've grown fond enough of it that I'd feel rather lost without it, actually......
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Simon
Discovering Something that Doesn't Exist...
Radix Lecti Rex |
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