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Distance between Top and Bottom Faces

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I got my jig and foam pieces cut perfectly but... Bonding the top of the box to the sides creates a gap which is filled with micro. Similar to the top, there is a gap between the bottom of the box and the sides. Adding these gaps results in an extra 1/8" distance between the top and bottom face in a few spots when checking with the spar cap templates. All other dimensions came out very acurate.

 

I've not glassed any of the outside of the box. Is it critical to get this distance exact? Should I bother sanding to make up the difference or is there slop up an down when installing the spar into the plane?

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I think I may have found out the answer to my own question.

 

CHP14 PG5 provides dimensions of the finished spar. These dimensions match what I built quite closely. Also, when I measured the cutout for the spar in my fuselage side pieces, it matched almost exactly what I built.

 

It's still a mystery to me why my templates don't match what I built though!!! I must be missing something.

 

When my next shipment of epoxy comes in I'm going to move forward with what I've got and cross my fingers.

 

-Mike

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It's still a mystery to me why my templates don't match what I built though!!! I must be missing something.

That could be a 'flag' that you did miss something. Perhaps not, but you do want to be sure. Did you account for the width of the glass? 11-plies = 1/8", etc.

 

When my next shipment of epoxy comes in I'm going to move forward with what I've got and cross my fingers.

That often works too. :)

 

I'll try to give this section a peek too. I'm curious how the spar fits into the space I cut out for it.


Jon Matcho :busy:
Canard Zone Member & Administrator
Now:  Rebuilding Quickie Tri-Q200 N479E
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The center section of the spar simply slides into the two square holes you cut out of the aft section of each side. The Firewall will push directly against the aft side of the spar and the trailing edge of each side.

 

The plans say you may have to shim our cut out foam or wood to make it fit. My cutouts match the spar +/- .05". I suppose this means that as long as I assemble the fuselage correctly I won't have to shim our cut out. If however my sides are assembled slightly catawampus, I'll have to carve out the sides to fit...

 

Still don't understand those templates.... The way they work is that you "hook them around the leading and trailing edge of the spar. Unfortunately if you measure the distance between these "hooks" it is inconsistent with all other means of determining the dimensions of the spar. For example here are my measurements:

 

5.3" = distance between "hooks" on the bottom spar cap template BL0

5.5" = distance between forward and aft foam faces of my spar at BL0

5.5" = depth of the cutout on each of my fuselage sides

5.5" = front to aft face distance at BL0 per CHP14, pg5

 

ALSO, if you add the height of the jig used to build the spar at BL0 to the thickness of the foam top (5.12" + .25") = 5.37", the distance between the hooks is still too close even if you have a gap of 0" for micro and layups!!

 

The only explanation I can think of is that the thickness of the foam I am using is slightly thicker than the foam used by Nat in his design by .07" AND the dimensions per CHP14, pg5 represent the finished spar with an additional .2" for exterior layups on the spar.

 

Given the instructions say you may have to carve out some foam or shim to get the spar aligned correctly, I have a feeling it doesn't matter.

 

I sent Nat an e-mail but he didn't respond. Maybe I'll try and give him a call.

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