Randy
If more time can be done in your site I'm sure Chris will find a way to do it!
I usually look for the weakest wood I can find for flaps. When I see wood on Tim's website that is listed as "P" in the SC column it catches my eye for glider flaps. I think that his testing and grading is just as valuable to find the most flexible wood as it is to find the stiffest.
The posts about wing bending causing the flap deflection have started me to thinking that might be the most important effect that is happening. Or at least as important as the bending strength of the flaps themselves. It for sure helped me find the problem in my new glider. The flap strength was very near equal but the left wing main panel was bending too much. As soon as we have another dead calm evening I'll be back outdoors testing again - hopefully tonight.
----- Original Message -----
From: rreyno2001
To: Indoor_Construction_at_yahoogroups.com
Sent: Monday, February 12, 2007 2:53 PM
Subject: [Indoor_Construction] Re: IHLG Flappers
It seems that there are a lot of similar experiences but perhaps
what is needed is some common data on the flaps themselves. As a
guitar maker deflection testing is commonly done in my craft to find
the lightest/strongest wood and wouldn't something similar make
sense here? perhaps not the strongest per weight but most flexible
per weight??
Chris mentioned to me that he tests the flap by measuring on a gram
scale how many grams it takes to deflect the flap to zero degrees.
He feels that number should be one half of the glider weight.
Hopefully I have that right.
It would also seem that actual measuements of the flaps are only
somewhat useful given the above since the flexural strength of each
individual flap wood can differ.
Personally I prefer to develop a sense of this rather than measure
preferring things to be intuitive but in this case I don't really
have enough experience to do that.
Talking of times....I am envious of the times I see being mentioned
under Cat I sites where our own Cat II 37-39' site record stands at
less than 40 seconds. This 6500' altitude has quite an effect I
guess.
Randy
[Non-text portions of this message have been removed]
Received on Mon Feb 12 2007 - 12:03:45 CET
This archive was generated by Yannick on Sat Dec 14 2019 - 19:13:44 CET