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Kites! Kites! Kites! => Kite Building and Repair => Topic started by: Roger on September 10, 2017, 09:48 PM



Title: Carbon vs. Wood
Post by: Roger on September 10, 2017, 09:48 PM
I have been building some cellular kites using 1/4" wood dowels, most around 2 ft. long. My questions are what diameter carbon rod/tube would give similar strength and stiffness as my wood, and how would a similar performing carbon strut compare in weight and cost? (A 2 ft. 1/4" dowel weighs ~8.3gm & costs ~50 cents.) Thanks.  :)


Title: Re: Carbon vs. Wood
Post by: thief on September 11, 2017, 06:46 AM
Mr. Chilese used to have a chart that showed spar materials, strength and deflection...maybe he can pull it back up for you.


Title: Re: Carbon vs. Wood
Post by: Allen Carter on September 11, 2017, 01:13 PM
All the charts I've seen compare FG and carbon, but not wood. 

HMmmm...

Maybe Rec.kites?


Title: Re: Carbon vs. Wood
Post by: Allen Carter on September 11, 2017, 02:37 PM
https://books.google.com/books?id=buvtiiXX4lMC&pg=PA58&lpg=PA58&dq=stiffness+and+weight+of+kite+spars&source=bl&ots=Jm9WJvAwZE&sig=WTQrm4eY0QseR6HWgi-rndUDuMo&hl=en&sa=X&ved=0ahUKEwiyreKLi57WAhXFy1QKHVrUC_gQ6AEISTAG#v=onepage&q=stiffness%20and%20weight%20of%20kite%20spars&f=false


Title: Re: Carbon vs. Wood
Post by: Roger on September 11, 2017, 09:33 PM
Thanks all!
https://books.google.com/books?id=buvtiiXX4lMC&pg=PA58&lpg=PA58&dq=stiffness+and+weight+of+kite+spars&source=bl&ots=Jm9WJvAwZE&sig=WTQrm4eY0QseR6HWgi-rndUDuMo&hl=en&sa=X&ved=0ahUKEwiyreKLi57WAhXFy1QKHVrUC_gQ6AEISTAG#v=onepage&q=stiffness%20and%20weight%20of%20kite%20spars&f=false

Interesting resource! Had to look up 'ramin' dowel; you too?

What I am trying to get at is if I can get the same stiffness & strength I have with the wood, with a smaller diameter and lighter material. I'm pretty sure wood can't be beat for price and I have only broken sticks when assembling. 'Course I haven't had the kites out in a gale yet but I am eager.

I notice the book writers criticize wood as 'prone to warping after extended use especially under humid conditions...' to which I reply 'paint & replace'. :D

A word on wooden dowels that I have found in the last couple months. The best I found -and bought out- were Poplar dowels at Lowes. Best as in fewer searched through for straights, consistent diameter, good stiffness. Having bought out Lowes I got some at Fred Meyer which were inconsistent in diameter and mostly crooked. Then to Home Depot where the dowels were unspecified wood made in Vietnam (ramin dowels perchance?) and they were uneven in diameter, splintery, and crooked.

Time to check back at Lowes for the new shipment. Happy sparring!


Title: Re: Carbon vs. Wood
Post by: Allen Carter on September 13, 2017, 09:52 PM
I forgot that Mike's chart had wood:

https://www.sysmatrix.net/~mikenchico/Spar_Deflection.htm (https://www.sysmatrix.net/~mikenchico/Spar_Deflection.htm)


Title: Re: Carbon vs. Wood
Post by: Roger on September 15, 2017, 10:32 AM
I forgot that Mike's chart had wood:

https://www.sysmatrix.net/~mikenchico/Spar_Deflection.htm (https://www.sysmatrix.net/~mikenchico/Spar_Deflection.htm)

Thanks Allen. Added to my bag. :)


Title: Re: Carbon vs. Wood
Post by: browndude3649 on September 16, 2017, 06:32 AM
Don't forget the s'more s bamboo sticks and other BBQ skewers are on sale at ur local supermarkets since summer is over with. 


Title: Re: Carbon vs. Wood
Post by: Roger on September 22, 2017, 12:32 PM
Don't forget the s'more s bamboo sticks and other BBQ skewers are on sale at ur local supermarkets since summer is over with. 


I had no idea what you were talking about until I saw some of these at the market yesterday. In end of summer basket no less!  :D It was a pack of 4 sticks which looked straight, about 3/16" x 30". Didn't get them as couldn't find price and I am working with 1/4".

I did track down the manufacturer of the Poplar dowels I have been getting from Lowes; it's Madison Mill, Inc. (http://madisonmill.com/) in Ashland City, Tennessee. Looks like they are primarily a wholesaler but will take minimum orders of $500.   :( 'Atsa lot o' sticks!  ???


Title: Re: Carbon vs. Wood
Post by: browndude3649 on September 24, 2017, 01:36 PM
I bought a 14 footer from West coast bamboo wherehouse   in Benicia calif. If your into making a mess of ur patio splitting and stripping spars to size. New skills!
Secret is toget a pole with 20 inch distance between nodes.


Title: Re: Carbon vs. Wood
Post by: ezme6 on September 25, 2017, 06:49 AM
i get my dowels here

https://wood-dowel.com/hardwood-dowels/?gclid=EAIaIQobChMIuJPN67zA1gIV2rjACh2x2gCZEAAYASAAEgK3xfD_BwE


Title: Re: Carbon vs. Wood
Post by: Roger on October 01, 2017, 02:13 PM
i get my dowels here

https://wood-dowel.com/hardwood-dowels/?gclid=EAIaIQobChMIuJPN67zA1gIV2rjACh2x2gCZEAAYASAAEgK3xfD_BwE

Thnx ezme. I see on their front page they list Poplar sticks, but I find them nowhere in the ordering section. :(

What sticks are you buying? (Size and material.) I am reticent to buy online as I will be stuck with crooked sticks I can't use. At the lumber store I can sort through and choose only straights sticks. What's your experience buying online in this regard?