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Old 11-21-2014, 07:17 AM   #25
Lynn Matteson
Join Date: Dec 2008
Location: Grass Lake, Michigan
Posts: 48
Default Re: I still need float-rigging info

Originally Posted by av8rps View Post
I put at the end of this post a random bunch of old photos I had saved of Kitfoxes with Zenair or Czech floats installed....Paul
Thanks for the updates, Paul. I haven't re-read the original posting (with edits) nor all of the latest, but just skimmed it enough to make a reply. The one thing about rigging that Zenair DOES make available are machined fittings that fit the Kitfox IV factory-welded brackets. I already have these fittings and all the strut and diagonal brace material, and of course the plane has the 4-on-each-side float/ski brackets. Yesterday morning, after thinking of how to make the rigging somewhat adjustable, I laid an aluminum bar across the pickup tubes on one of my floats...fore and check on the feasibility of making the throat adjustable. I leveled the float so this bar was reading "zero" on a digital level. Then I placed a 1/2" shim under one end of the bar....the dig. scale read 0.5 deg. Then I removed the 1/2" shim and used a 1.5" shim (2x4) and the reading was 1.5 degrees. Swapping the shims to the other end, one at a time, and the reading were the same. In short, as luck would have it, whatever the thickness of the shim is in inches, adjusts the reading a similar number of degrees. So if I were to use, say, a 1" shim under each of the four rigging blocks that bolt to the spreader bars, then set the plane-to-float (throat angle) angle at say, 4 degrees, fly it, and if an adjustment were necessary, I could remove the front 1" shims, and the throat would close up 1 degree to 3 degrees, or remove just the rear shims, and the throat angle would open to become 5 degrees. Or, if the plane flew well at the original setting, I could remove all four shims, and still be at the 4 degrees of the original setup. Now, is this what others have done to have some adjustability, or am I all wet (no pun intended) on this theory? Using shims judiciously under what Zenair calls the "pickup fitting" which is shaped like a pillow block and to which all the fittings are attached, raises or lowers the entire rigging package...struts, diagonals, x-wires, and once, and no changing of the struts or diagonals is needed. So, in my thinking, I can easily change the throat angle, but it's the placemant of the step in regards to the C of G that would involve drastic changes of strut/diagonal tubing length if that original step/CG placement were not made right to begin with.
Your thoughts?

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