March 15, 2012 - Building the First
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The Triplane has how many wings? If you answered three, give
yourself a pat on the back! That means I'm going to have to build a
lot of ribs. 58 to be exact. Each rib is made up of the
following pieces: nose web, nose fillers (2), aft web, top capstrip,
bottom capstrip, front filler, top filler, top and bottom capstrip
fillers, and multiple vertical reinforcers. Glue all that together
with T-88 expoxy and you have yourself a Triplane rib.
Wow.
I made a "master" of all of the above. Then I can start mass
producing them.
Let's start off by making some nose webs. First I trace out the
nose web outline on my 1/16" plywood sheet. You just don't
drive down to the Home Depot and pick this stuff up. I ordered mine
from an aircraft supply mail order company called Wicks Aircraft
Supply. The plywood itself 1.5mm 3 ply and made in
Finland by a company called Koskisen. The plywood grain has to
run lengthwise on the web.
I cut out the webs using my jigsaw and bandsaw. Then I cut two
lightening holes in each nose web using my hole saw blades on the drill
press. It's obviously high quality. It doesn't splinter at all
when you cut it. |
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| Next I had to make
two nose web reinforcers. These are cut out of 1/4" plywood.
Because of their shape, it is time-consuming to cut them. First I
used the band saw to make the cuts as shown. |
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| Then I used my
step-bit to make holes big enough to get the jigsaw blade in. |
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After using the Jigsaw,
voila! Now I could cut each reinforcer to the exact shape
using the bandsaw. I'm going to wear the bandsaw out with this
project. |
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| OK, a batch of 10
nose webs are ready for glueing. |
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Here is one after glueing. I
used a couple of little brass nails to hold the nose web together while it
cured 24 hours. |
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| Next item on the
agenda was to make aft webs. I used the same 1/16" ply as the
nose webs. I cut them out using the jigsaw and bandsaw. Then I
cut the holes with different size holesaw blades -- the smallest one inch
blade is shown. Finally I used a square hole punch -- acquired from
Micro Mark -- to make the square hole near the training edge of the
web. This is where the 1/2" by 1/2" rear spar will run
through. The aft webs are time consuming to make as
well. |
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| Four out of five
holes done on each aft web. Once the holes are drilled, they
must be sanded smooth. |
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| A batch of seven
aft webs are complete. |
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| The top and bottom
capstrips are made out of 3/8" by 1/4" spruce. However, the plans
call for cutting a 1/16" slot lengthwise. I searched high and low
for a tablesaw blade with a kerf of 1/16" but I simply could not find one
at a store, on the internet, or someone to borrow one from. I
was about out of ideas when my brother-in-law Mark told me his neighbor
was a master woodworker who had all the tools. So we went over to
his house. He pulled out a 1/16" kerf blade from a drawer and had
his table saw setup for the job in about 10 minutes. Then we spent
about 30 minutes running about 450 feet of 3/8" by 1/4" through the table
saw. The capstrips came out perfectly. |
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| And here are the
results. |
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| The top capstrip
must have a permanent bend in the front portion. This is done by
soaking the end in 13" of water for three days. |
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And then put three soaked capstrips at
a time in the bending jig for another three days. |
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| And here are a
batch of top capstrips after the bending process. I also had to trim
each end to the proper shape per the plans. |
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| The bottom
capstrips don't get bent but they do need trimming at each end. |
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I had to make these little capstrip
fillers. The go in the capstrip grooves where the box spar runs
through. |
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These are all the future rib vertical
stiffeners. They don't go on the rib until after the main part has
been glued together. |
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| The rib pieces go
in the jig to make sure they all fit together. An bit of sanding
here and there was required occasionally but all in all, most of the ribs
fit together pretty well. |
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| Ready for
gluing. I have my T-88 epoxy containers, paper bowl, weight scale,
and rubber gloves. |
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| I mixed up some
epoxy, put it in the capstrip grooves and then put the rib together in the
jib. Then let it sit for 24 hours. |
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| Still curing. |
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The rib looked pretty good after I popped it out of the jib.
There were a couple of globs of epoxy that needed cutting off or
sanding. But all in all, it seems pretty solid.
I fitted the vertical reinforcers and am ready to nail/glue them
on. |
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And here is the final product with the vertical reinforcers in
place.
The first rib is done! 57 to go. |
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