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Step 2 ASSEMBLY OF FOAM PARTS |
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I don't know about the rest of you, but I'm officially
tired of measurments like 8.51, and 40.26, and 28.36, etc. Obviously,
this airplane was scaled from some other normal size, and, when the math was
done these were the measurements we ended up with. Well, I can't read even
a decimal tape measure to the hundredth of an inch (and don't tell me you
can either, 'cause, no matter what you say, you can't) so I dug out my dial
calipers, big ones. Set that puppy to 8.51 inches, use that to set the
width gauge on the band saw, and 'oila! As close to 8.51 inches as I'm
gonna' get! Stick that foam in there and cut away! |
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Many of these parts need micro joints to be big enough.
I use the hinge method to do this,
tape on one side (box sealing tape I think works the best, sticks less than
other types once the micro has cured) crack open the 'hinge', add micro,
hinge back together, remove excess micro, tape on top, let cure. |
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Here's a shot of my foam parts, having been cut to size,
curing after being microed together into the bigger pieces. |
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This spar has a lot of confusing changes in shape. I
laid these parts into the jig to help me understand. I also labeled
extensively so I would not mix any parts up. Having said that, if you
cut all the pieces out to the right size, there's really only one way they
go together, fitting into the jig. |
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My Shurform plane made quick workof carving the foam to
match the jig. Some builders have a love/hate relationship with
urethane foam. Me, I don't mind. Easy to ding it with tools
without even thinking about it, but, it sure carves nice. |
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Lots of micro is used in this step, and you have to spread
it over a real long piece of foam. Use the
plastic bag method to keep this easy and
avoid getting micro all over the place. |
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Here's a shot of the forward, top and bottom faces microed
together in the jig and waiting for cure.
I've added some boards and weights to keep everything in place and the
top/bottom faces squeezed tightly onto the forward face, to avoid any gaps,
as the micro cures. |
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A fun shot of the spar from one end. I used T pins,
compliments of my R/C modeling days, instead of nails like the plans call
for. Smaller holes, same effect and purpose. |
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A couple of the pieces I had to make up by joining smaller
pieces of foam. I think I made my F-0 out of one piece of 1/4" PVC
that was supposed to be for this. |
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The CS-5 and CS-8 bulkheads are added to the ends after the
top, bottom and and forward pieces are joined. This jig is a little
long in length, that's good in this case 'cause it helps line up these
bulkheads properly, flush to the other faces. |
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I tried very hard to keep excess micro from making a mess
inside the spar as it squished out once the pieces were joined. Sure,
you will have to add micro when you do the interior layups, but I'd rather
have to add a little than to have a cured micro lump I can't glass over
without a bump.... |
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I missed one spot, and it wasn't even in a corner, it was
on the flat inside. I trimmed this back with my Dremel and it was then
smooth enough for glassing over. |
Chapter 14
Step 1 Chapter 14
Step 3 |
