Inboard cores

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Time to give life to these square blocks.

Feb 4, 2004

This is the entire right wing. Left to right, inboard, center and outboard sections. You can't see it, but the side cuts are at 11.4 degrees because the wings sweep back. Which, gives this plane a very cool look!

Here we have the right inboard core cut to shape, not including cutting the shear web. I layed my block on the table, (which of course, is not perfectly flat) and there were some gaps between the foam and the table in various places. I left them alone because the foam itself was very straight. I did not want to place weights on the top of the foam because I think that would put stresses on the foam, and when you remove the finished product, I think that would contribute to a "bent" foam wing section. So, in place of putting the weights on top to hold everything in place while cutting, I just put small amounts of 5 minute epoxy where the foam meets the table. When I removed my core, it was as straight as a laser. I was lucky and my foam came at 8" thick. Maybe even a little more. So I did not have to add the extra small piece on the top. I also, started the cut in the tail, and worked forward. (opposite the plans) And during the cuts, did not cut the spar caps, just went right on by. I came back and did those later, and they turn out better that way. Also, when I cut the canard, all the talking numbers are in "tune". 1,1 2,2 3,3 but this inboard core was different. The spacing is off so one person must go at a different rate at times.

Obviously, the top was cut first. Not only are the horizontal level lines of both templates level with each other, they are also coincident. (the same dimension down from the top of the foam, or up off the table)

Here is the guy that I will be summonsing to my house every time I need help with a cut, my dad.

I ended up building a small platform using 2x3 lumber and particle board to rest all the foam cores on during cutting. I hand picked very straight 2x3s. It's a box design, so it's very straight and flat. I set this on my crooked-as-hell table and you could see all the gaps and taper of the table it rested on. I leveled it and bondoed it to the table. Turns out, I should have made it a little longer. If I had, the ends of the foam blocks would have not stuck out the ends, and I could have leveled the water lines a lot easier by measuring up from the table top. But, like I sometimes do, it was Sat morning, and I got in a hurry and went with my first thought so I was stuck with it. Sometimes I just want to build FAST and get crap done. But, I've found the MAJORITY of the time, if you try to make good time on your building, you have a good chance of missing something that can come back and bite you. There's always something else to consider not just the one instruction you are working on.

Before cutting the shearweb off

After cutting the shear web off

Left and right side by side

To attach the two sections of this piece together, right after I finished the cutting, I applied micro to both surfaces, (slurry because I had a perfect fit) and layed it right back in it's home and re-installed the templates while the epoxy cured. That does it for the inboard cores. Time to do the center cores.

Regarding my M drawings to make wing cut templates, when I cut them out of the M-Drawings and laid them out, some of the level lines were bowed. AND, on the lower winglet tip template, the tail section that you line up to the main section, was like it was printed a different scale! The airfoil lines didn't even match up. I don't know why and frankly, I didn't feel like spending time investigating, so I just took a straight edge and lined it up with the leading edge of the line, and the trailing edge of the line, and drew another line, and "called it good". The cozy mailing list had a bunch of talk about template/drawing issues, but I think the amount that they might be off, is NEGLIGIBLE. Guess what, a long time ago, I had a quicksilver MX ultralight, and it was getting COLD in Nebraska, so I wanted a windshield. So, I ordered a sheet of thin Lexan material and some round alum tubing. Bent them to shape, riveted the lexan plastic to the tubes, and attached the whole thing to the plane. Now, this shield was BIG. This was a major aerodynamic change. Come to think of it, this was probably a pretty stupid thing to do. Anyway, I proceeded to taxi down my gravel driveway which was my runway, and gave 'er hell. Yep, she flew, but there was a bit of new stick pressure that was not there without the wind shield, but she flew all right. My point is, if a line in the M-drawings doesn't quite line up DON'T PANIC.

Time to cut up FC1 inboard core to create a shell to make room for some hardware. I used my large bandsaw for this cut.

My wide saw blade couldn't turn any corners so I cut from leading edge rearward on BOTH sides, then cut the front piece you see here, OFF of the piece I had just cut out, then here, you can see it being glued back in place. If you go this way, push nails in the foam BEFORE you make the cut, then when you put it back together, WALLA. Guaranteed to go where it was.

My saw blade was .050 thick, so before I microed it back in place I glued these .050 spacers. Necessary? I doubt it, but it makes my happy. And that's what this is all about right? Allright then!

Gluing the shelled-out end of FC1 back in place. One area was bowing out, so I had to glue two mixing sticks together so they would not bend at the foam join.

Little moments like this sure are fun. Seeing all the pieces come together.

Email -- Jay Hegemann