Re: Q2 LS1 Carbon spar?


JMasal@...
 

Wether you use expanding urethane, stacked foam or artichoke hearts to make an airfoil make sure you STATIC TEST IT and not half-assed but like the professionals do.

j.


-----Original Message-----
From: Mike Perry dmperry1012@... [Q-LIST]
To: Q-LIST <Q-LIST@...>
Sent: Sat, Sep 6, 2014 10:52 pm
Subject: Re: [Q-LIST] Q2 LS1 Carbon spar?

 
Hello Jim:

Your advice to contact some of the other people in the QBA is excellent; actually, I did just that.  A few years ago I went to Livermore, talked to Bob Farnum and Barry Weber and we came up with a plan for reconstruction.  But then I ran into my own anxieties. 

The builder of the project I took over built and flew a RV-4 and an ultralight; however he never completed a composite project and I can no longer talk to him (in very poor health living in another state).  The builder's log consists mainly of photographs which tell me a lot -- but don't tell me some critical factors.  I remember the cause of Bob McFarland's Fatality: wing assembled with the wrong materials (expanding urethane) leading to delamination.  I think there was another wing failure involving a foam core assembled from several pieces of foam stacked together.  Not sure I can complete this project -- Still thinking about it.

The advice about the Dragonfly spar is excellent.  I will see about getting a set of plans.  On the other hand, maybe I should just get the Quickie plans and start over, build the single seater.

Mike


On 9/5/2014 7:43 AM, JMasal@... [Q-LIST] wrote:
 
Mike,

It would have been very dumb of me to print detail plans for alternate spars in QTALK (I didn't just fall off a turnip truck, hee hee). That would be hand holding in my estimation AND liability dangerous given the critical nature of the part and the lack of successful flight testing. In the spirit of "education and recreation" and sweat equity I pointed out possible directions to go. For example many Dragonflys are operating successfully with builder built spars. As noted in another post, Doyle and Weishaar built one with their own brainpower which was proved successful. I was told QAC's first one used all carbon layups a la the GU... and there were a couple other trials underway about which more I have not heard.. We have some sharp cookies in the QBA and I believe if I or any of them had your canard and if the spar was not mutilated we could extract it and use it in a new build. If you had built a Q in the first place you would have enough composite knowledge and skill to figure out how to do it. Sweat equity... not avoidable with a skinny bankroll.

You are wise to be suspicious of the rest of the build job given the problem with the canard. Your $$$ AND Life depend on it. You might coax a successful builder to examine your carcass to give you some peace of mind... or not.

j


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