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Ferris
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Tapered lower spreaders

Thu Nov 11, 2010 10:45 am

Is there a right or wrong end to cut off when sizing your new replacement lower spreaders:? I've cut down the thinner end until now. any thoughts?

Mike
 
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mobius
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Re: Tapered lower spreaders

Thu Nov 11, 2010 10:55 am

If you cut the thicker end you might not be able to get the ferrule in.. also a lot of stress is put on this section so cutting could weaken it.

Should always cut the thinner end in my view.
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Re: Tapered lower spreaders

Thu Nov 11, 2010 11:43 am

Yes you should always cut the thin end, the fat end usually has an extra wrap of carbon for strength at the ferrule.
 
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Will S
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Re: Tapered lower spreaders

Thu Nov 11, 2010 2:02 pm

Depends partly on the spar - aerostuff, PT series, or G-force spars need to be cut on the small end. The first 14" of a nitro spar are not tapered and so you can cut off the large end of nitros to change flex characteristics a bit. Cutting off the large end will reduce stiffness tiny bit but will improve durability since it will be slightly less brittle because of the slightly smaller diameter throughout.
 
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Aeri
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Re: Tapered lower spreaders

Thu Dec 09, 2010 6:30 pm

Cutting off the large end will reduce stiffness tiny bit but will improve durability

no it wont... (durability)... it will reduce that.
the large end of a tapered tape is meant to be left alone and the carbon is thicker there (more wraps as stated earlier in this discussion) and built for the connection with the inner connector or even a ferrule. if you cut this extra layer the tension of the kite is put on an unprotected part of the rod and it will split open
dont forget, this part of the kite takes almost all of the forces during flight...

the sail takes the wind... the forces on the sail are taken by the centerspar and the who leading edges...
this force is inward (sail wants to fold together, the leading edges hold it open and stretched while the centerspar keeps it in shape in the middle...)

all that force is transferred on the only solid parts there.. the upper and lower spreaders.
the upper spreader is one peace so... no real weakness... but it hardly takes any forces... (fly without one in a bit of a wind an all the kite does is bend a bit)
but the lower spreaders take the bulk of the force here... and release it on the center T... that point is the part that hold all the force generated by wind and speed and us lot trying to get the poor kite to stuff like lazy's and spins and so on... so you want to keep that spot as well protected as possible...

thats my idea anyway :-)
Old school was a great school
 
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Will S
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Re: Tapered lower spreaders

Thu Dec 09, 2010 8:39 pm

Aeri wrote:
Cutting off the large end will reduce stiffness tiny bit but will improve durability

no it wont... (durability)... it will reduce that.
the large end of a tapered tape is meant to be left alone and the carbon is thicker there (more wraps as stated earlier in this discussion) and built for the connection with the inner connector or even a ferrule. if you cut this extra layer the tension of the kite is put on an unprotected part of the rod and it will split open
dont forget, this part of the kite takes almost all of the forces during flight...



That holds true for all spars I know of except for the nitros, which is why I put that stipulation in.
I have talked extensively with Jon T on the subject and what I put is a paraphrasing of what he told me - not my own thoughts. I think he probably knows this sort of thing pretty well.
 
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Re: Tapered lower spreaders

Thu Dec 16, 2010 10:55 am

Spars are Black Diamond Nitro's and i've cut the small end off!