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Joe's Life



140111aa:

Click on a thumbnail to see the picture or movie.
01-11-14: Construction began by building two (left and right) frames
from 1/16" balsa. Description not available. 02-15-14: I epoxied the frames to 1/64" ply and trimmed/sanded the
resulting assemblies to precisely the correct (and same) dimensions. 
  Here they are pictured after sealing with a carpenter's glue based
sealer.  They are pinned down to prevent warping while
drying.<br><br>

Also pictured here are two parts made from 1/8" ply.  On the left
is the base of the pod, and on the right is a frame-shaped piece that
covers the diagonal area.  It serves as an air in-let and as a
place to run the power and throttle cables.
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Description not available. Description not available. Description not available. 02-22-14: I used epoxy to glue the sides to the base.   The base
has the mounting holes already drilled to match the holes in the
wing.<br><br>

[The holes in the wing are another story.   In several of the
other photos you can see the sticks of spruce that I shaped and glued
to the top and bottom of the wing.  These sticks have holes in
them for the bolts to mount the pod.  The bolts pass through the
wing and secure with nuts on the bottom side.  For strength and to
make it easier to put the bolts through the holes each of the four
pairs of holes (top and bottom) has a straight piece of brass tube
connecting them.  The brass tube is glued into the spruce on the
top and bottom and passes through the wing.  The spruce and brass
tubes were already installed, since I had used them to mount the pod
for the Black Widow .049 which was in use before I converted to
electric power.]<br><br>

And I marked in pen on the base lines showing where the sides should
attach.  There isn't much room for mistakes here, because the pod
sides just fit between the holes.  I didn't plan it that way--I
got lucky: The diameter of the motor and heat sink plus the thickness
of the two sides equals a distance just less than the space between the
edges of the mounting holes.<br><br>

The trick in attaching the sides to the base is to get everything
straight, parallel and perpendicular.  To do this, I made a balsa
spacer from three pieces of 1/16" balsa.  I cut them slightly over
the desired width, 0.875", then I carefully sanded them down, checking
with a caliper, until they were 0.875".  It went something like that
anyway.  I assembled the three pieces into an I shape.  the I
was about 2.5" high and about 3.0" wide.<br><br>

[Actually, I found it necessary to cheat a little.  I reduced the
width of the front end of the lower piece of wood in the "I" to 0.855". 
That allowed me to make that portion of the pod have sides that were
slightly closer together.  I needed that because the front holes
in the wing were slightly closer together.]<br><br>

This I-shaped spacer was then rubber banded firmly between the two
sides.  After trial fitting and checking that the fit was correct
I then applied epoxy to the base and carefully placed the rubber banded
assembly onto the epoxy.  If I do this again, I might use a few
pins to strengthen the assembly, as the rubber bands were not quite
enough to hold it steady as I adjusted the position in the still wet
epoxy.<br><br>

I let the assembly stand on the base while the epoxy cured. Description not available. Description not available.
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Description not available. Description not available. Description not available. Description not available. Description not available. 03-23-14: This shows the hatch, one piece of 1/8" balsa, and the top,
made from four pieces.  The four pieces of the top are, from left
to right, 1/8" ply, 1/8" balsa, 1/8" ply, and 1/8" balsa.<br><br>

All of these pieces show computer paper bonded (with 3M General Purpose
45 spray adehesive) to the top side.  I experimented with this new
way (new to me) of building.  I made plans for all the parts on my
computer.  (I used free software called Xfig on a Slackware Linux
based computer.)  When I had parts to cut or drill I printed the
plan and glued it to the wood with the spray adhesive.  Then I
drilled on the marked centers or I cut beyond the marked edge, then
sanded down to the edge.  This helped, but I still found I had to
use great care when drilling holes or shaping a part.  It helped
to make an indentation with a center punch before drilling a
hole.  And I went slowly when shaping a part.  It helped to
use calipers to check the dimensions periodically when sanding down to
a line.<br><br>

The top was a nasty part to sand.  Assembling it from the four
pieces was easy enough, but sanding the edges round, after it was glued
to the top of the pod assembly, was difficult.  The alternating
hard and soft of the plywood and balsa was hard to sand to a uniform
shape.  If I build another one of these I may make some changes to
avoid this problem.<br><br>

I should explain that I bought a new tool, a Two-speed Dremel motor
tool and a Dremel drill press.& The two work together and are in some
of the pictures of this collage.  They worked well with this new
way of building.  I made much use these attachements:<br>

   <ul><li>various drill bits<br>
   <li>cylinderical sanders--good for shaping<br>
   <li>a cutter that looks a little like a drill bit, but cuts on its
   side--good for rough cutting<br>
   <li>the cut off wheel--good for cutting the bolts that mount the
   pod<br>
</ul>

By the way, the computer paper sanded off more readily if moistened it
a bit.  I do recommend removing the paper, though.<br><br>

I need to explain the three holes in the top.  Originally I
planned to run a wire tie through two of the holes and around the motor
to brace it against the top.  The third hole was to help position
a pad that the motor would rest against.  As I was building I
decided that the strap and pad were not needed, so I kept the holes for
extra ventillation.
Description not available. Description not available. Description not available. Description not available. 04-02-14: I used a Himax 2025-3200 inrunner for power.  Here it is
with the homemade heat sink installed.  The heat sink is a
rectangular piece of .005" copper sheet.  I think it is seven
inches long, the full length of the K&S Precision metals stock that I
bought (#15058 1piece each of brass, aluminum and copper).<br><br>

I loosely folded the copper sheet in the middle and put the motor in
the fold.  Now the sheet is U shaped.  Then I pressed the two
legs of the U together, fully enclosing the motor.  I pierced the
two legs of the U in three places to allow three zip ties to be
threaded through, but I didn't install them yet.<br><br>

Next I gently bent the U open enough to remove the motor.  I
smeared Ceramique heat sink compound (from a computer store) on the
case of the motor (after first removing the label from the motor), and
I carefully put the motor back into the U.  I pressed the U closed and
installed the three zip ties, pulling them tight.  The location of
the zip fasteners is important, since the pod is just slighly bigger
than the motor.  The zip fasteners go in one of the upper two
corners of the pod (where the sides meets the top), so position the zip
ties this way before you fully tighten them.  Likewise you should
position the motor how you want it.  I installed mine with the two
mounting holes horizontal (left and right of the shaft).<br><br>

Finally I wiped away the extra heat sink compound and shaped each of
the two legs of the U into an S shape. Description not available.
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Description not available. Description not available. 04-22-14: I put ventillation holes in the hatch/canopy to cool the
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© Joseph Rosevear
  |   Source touched: 2024-09-27 16:28:54