4 Apr 2010
Did a short stint of work today on the Odyssey PC925 battery box. This
part
replaces the two battery tray side bars, the hold-down bar, and the two
hold-down
bolts of the RV-10 kit. Unfotunately, it doesn't match the hole pattern
for the
kit's side bars. I went ahead and lined up one hole (the front right
one) just
to save work. This kept the right-side holes aligned over the rib rail
beneath
the battery tray for support. However, the left-side holes were well
inside of
the left rib rail so they'll have less support. I started off by
drilling a new
#12 hole for the front-left battery box hole, then adding countersunk
rivet holes
for a K1000-3 nutplate on the bottom of the batter tray.
The forward-left corner becomes problematic. What was originally the
forward-left
hole for the battery tray side bar is now unused. But it is the only
thing nearby
that secures the battery tray to the rib rail underneath. So I'd
really like
to just put a bolt in there anyway. However, the hole is too close to
the edge
of the battery box to accept a bolt head.
I thought about making a shim that is the same thickness as the battery
box
flange and then bolting that down, but I think instead I'll just make
part of
the airframe ground bracket (which will eventually be attached in the
blank area
of the battery tray just forward of the battery box) stick out over this
spot and
act as a shim. Either way, both the new and the old battery hold-down
holes will
have bolts in them.
Turning to the aft end of the battery box, we have even more problems.
First,
the aft-left hole required a new set of nutplate holes which are also
not
supported by the rib rail. Again, the existing hole is now too close
to the
box to accept a bolt directly (though in this case filing down the
corner of the
box may suffice). The bigger problem is on the aft-right side, where
the new hole
through the battery tray and the rib rail beneath is too close to the
existing
nutplate rivet hole for the old side bar hole.
I'll have to add a nutplate for this hole that only has one lug, and I
don't
have any of those in the correct size. So that bit is on hold awaiting
more parts.
Actually,
everything is now on hold awaiting more parts. I
spent
a bit of time this evening thinking about exactly what I need to finish
all of
the accessories mounting in the tail cone, and came up with a big list
of hardware, tools, and parts that I needed to buy. $180 later, I'm now
on
hold. And it probably won't arrive before I'm off galavanting around
the world
again next week. So this may be the sum total of the work that gets
done on
the plane in April. Oh well... slow progress is still progress.
1 Apr 2010
No, it's no April Fool's joke, I actually found time to do more work on
the plane!
I spent a lot of time while I was out of the country doing some planning
for the tail cone accessories
and the steps required to install each. Tonight I put those steps in a
sensible order, and drew a line
on each list at the point where I would need to disassemble the tail
cone before continuing. Everything
above that line is now on the critical path. This evening I spent some
time getting the elevator trim
servo bracket assembly and static air system lists down to the
disassembly-required line.
First, I fabricated a small bracket that sits aft of the rivet line that
attaches the two halves of the
frame that sits just aft of the static airports. This bracket will
support the T-junction that joins
the two sides of the static air system. Here it is cleco'd to the
frame:
I discovered that if I put the 90° elbows coming right off the
static ports facing aft, they
poke right through the lightening holes in the frame. This allows me to
plumb all of the
static line and associated clamp hardware to the aft of the frame.
This, in turn, keeps all of it
out of the way of the skin rivets associated with the frame, which are
all on the front side. That
means that I can go ahead and run the static lines up as far as the T
junction before riveting on
the top skin, preventing me from having to crawl inside the dark
enclosed tail cone to do it later.
Here is a picture of the T-junction temporarily installed on its
bracket:
Next, I fabricated a little drop plate to hang off the side of the
elevator trim servo bracket.
It holds a panel-mount circular plastic connector for the five servo
control and sense wires.
With it fabricated, the elevator trim servo bracket parts are all ready
for priming. One more
small modification regarding elevator trim was to add a hole in the aft
deck for an Adel clamp on
the bottom face of the deck. This clamp will be the last support for
the cable that will eventually
connect to to the CPC in the drop plate.
The only other thing I did tonight was to mark some hole positions on
the F-1028 channel for Adel
clamps that will hold the top conduit on one side and the wire bundle
coming out of the overhead
console on the other. After marking the holes, this section was ready
for disassembly as well
and was moved off the critical path list.
Accessory assemblies still on the list of things to do before
disassembly:
- Top wiring conduit
- Bottom wiring conduit
- Airframe grounding bracket
- Main battery box
- Main battery contactor
- External power contactor
- Magnetometer shelf
- Oxygen tank
- Oxygen distribution manifold
- ELT
- ELT antenna
- NACA ventilation inlets