Re: Tri-Q finish weight and balance estimate [1 Attachment]


Lynn French
 

Jay,

None of us should be surprised that you are engineering this bird to the exactness that requires consideration of the uniformity of the paint. I admire your persistence and patience and hope to see this at fly-ins soon.

I don’t know why it seems to me that FS70 is too far back for the CG of the paint. Isn’t that about the center of the rear wing? Total surface area of the shell, top and bottom of wing, canard, etc. would seem greater in front of that point.

If your empty weight projections are true you are to be commended for an extremely light Tri Q. Remind me again of what your engine weight is.

 

Regards,

L. French

 

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Sent: Monday, December 28, 2015 10:24 AM
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Subject: [Q-LIST] Tri-Q finish weight and balance estimate [1 Attachment]

 



Hi All,

I have been noodling out some final weight and balance estimates for my Tri-Q. The biggest unknown remaining for me is the finish/paint and just where the cg of this is located. I am still a bit up in the air on what will be the total weight of the finish, but I am estimating about 30 pounds for the time being. I built a 3D virtual computer model of the outer skin of my plane (actually only the right half, since both halves are symmetrical), then fitted it with uniformly thick layer of small cubes covering the skin (these cubes are called voxels is the modeling lingo--picture below). This allowed me to compute the cg for a uniformly thick layer of finish. That computation works out to be located at FS 69.7, for what that is worth. I am sure uniform thickness is not a perfect assumption, but at least I have a starting point for adding paint to my overall cg computation. Comments welcome.

Hope you all have a great 2016. I know it will be memorable for me if I get my bird in the air this year.

Jay Scheevel, Tri-Q, still building


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