I will be starting a spreadsheet with the actual
weight of parts as they are built.
To
date:
Nose rib and mid rib
= 6 ounces
(and they transfer
100 pounds of lift to the spar at 4.5 Gs)
Spar with fittings = 6 pounds approximate (no
bolts yet)
Lightening holes in spar web saved = 7.4 ounces both spars |
Jim T. , Yahoo! Groups Sponsor reports:
A truss-built rib (nose and mid rib) at 5.94 ounces, or
8.395lbs for a set
Mike, Hummel Aviation, reports a set of formed rib at 9
pounds, 2 ounces
So the updated truss ribs are about 13 ounces lighter than the
laser-cut formed ribs.
|
100 Years of
progress
My first two ribs:
UltraCruiser
and 1903 Wright Flyer
(The Wright Flyer
was funded by
the State of Minnesota)
|
Better view of the
rib with flanging die
Circle hole
flanging die "turned" by Dale
Johnson
Modified nose rib per suggestion by Peter
Denny
(Sonex builder).
Bill Batzloff
also came to the same conclusion.
An additional change was made to the rivet pattern ... see below.
|
Built-up Nose Rib
for the WWII
Spitfire!
These two photos are from the March 2008
issue of Air
& Space
Note:
For comparison, I have
included photos of a built-up rib for the WWII Spitfire shown in the
March 2008 issue of
Air & Space magazine.
Compare the Spitfire photos to the photos below.
|
y
Spitfire Mid-Rib
and wing structure
If formed ribs are so great, why aren't they used here? I know why.
(By the way, I understand that Hummel makes a great set of formed ribs.)
|
Rivet Station ...
rivet squeezer clamped in vice
Note: see below for
a new holding fixture.
|
Reaching a
difficult rivet
Rail section holds
angle brace while allowing total freedom for placement |
Improved squeeze
rivet work station ... shown with nose rib.
Two tubes hold the
squeezer vs. clamping in the vise.
This allows
rotation of the squeezer.
The left or right tube is selected based on required
space for your hand
during the squeeze operation.
Note: Mounting
board is from a busted Ice Boat plank.
Huge aircraft bolt replaces railroad track. |
Squeeze rivet work
station - close view
Vice, squeezer, yoke and
support angle can all be positioned to reach
difficult locations
while ensuring that the squeezer is perpendicular.
Here the change to
the rivet pattern can be seen. The
lower flange is
made longer to allow the rivets to be longitudinal
rather than
perpendicular. Also, the formed piece has a
simplified corner
at the lower and upper -rear corners
allowing for a straight cut with your tin snips. |
Squeezer shown with
a mid-rib |
A "no space" plans
desk ... workbench to the right (not shown).
Fast and
inexpensive to build ... light weight, easy to move. |
Insert sides filed
flat for tight riveting ...
Note: if the squeezer inserts lean against the assembly,
the rivet will be driven crooked (bad) and may split (worse) .
(both
top insert and bottom insert have flat sides cut and polished) |
.020
aluminum sheet (4x8 foot)
ready for cutting ... no that isn't a mirror
|
Cutting guide is
clamped (not absolutely necessary) |
Inexpensive cutter
... make 20 strokes, bend and brake off piece./
As the groove gets deep enough, the cutting stroke makes a different
sound. |
Spar web, cap and
fittings ... temporary assembly.
Note: Basement
assembly workshop. Hopefully, I'll
lose 20 pounds
running up and down stairs between
the basement
workshop and the garage. |
Note:
The wing shown here
is the right-outer wing panel.
The total wing
consists of a center section and two outer wing panels.
Each outer panel is
a little about 9 feet.
The center section
is a little about 7 feet.
Total wings span is
25 feet. |
End view of fittings
Fittings machined by Dale
Johnson |
Three-quarter view of end fittings
End Polishing, more hole drilling and deburring remain to be done |
Top view of first trial assembly mating rib to spar. |
Photo by Dan Johnson
|
Review of wing assembly
Note: circle-hole flanging dies "turned" by Dale Johnson.
Too much effort vs. using a flanging hand tool?
(Not when some one else volunteers to make them!) |
Front view ... note
ribs for 1903 Wright Flyer on wall above
100 years and a
significant change in technology!
Take
a look at Mr. Fujita's wing with formed ribs:
also
His
complete gallery at the Hummel website:
|
Edge view ... note spar web vertical stiffeners |
Another edge view |
 |
3M polishing wheel ... source Avery
Tools (SKU 3753)
.... 6" 3M
SCOTCH-BRITE DEBURRING WHEEL
Available from several aviation suppliers.
This is the wheel recommended for RV builders.
Photo on left show the grove created to smooth edges on aluminum
This is totally SUPERIOR to any other method of deburring an
edge. |
More on this later ... see preliminary discussion to the right
----->
|
<------ Hole
drilling guide or Index Bar
I have tried a
number of methods to create an accurate hole guide.
In matched hole tooling, it doesn't matter if the guide is imperfect
.... as long as it is placed correctly on matching parts.
But, I wanted a guide that was perfect so that it can be flipped and
flopped and still drill a matching pattern.
In my scrap pile, I discovered an aluminum bar bought at a Control Data
employee sale
over
30 years ago. Aluminum was being sold at scrap prices.
This
bar is from a super computer chassis. It is straight,
relatively
thick and had accurately drilled holes at one-half inch
intervals. The holes were tapped for 6-32 machine screws.
These threads nicely capture the silver or the small Cleco
which fits a #41 or
3/32nd drill bit.
The holes are #35 drill in size. I have drilled out every
over hole and inserted
brass tubing which is then press fitted by pounding an awl into the
tubing
followed
by pounding on the end of the tube with an 1/8 inch drift punch.
This produces a hole that fits the smaller #41 drill for
3/32nd
rivets. I may drill out the other holes to fit a #31 drill. |
|
Work bench, plans table, shelving and tool stands.
Table saw and compound cross-cut saw under work bench. |
Small belt sander to the left, bench drill press (center
left) and band saw (far right)
Shelving holds drill accessories, battery chargers, hand drill stand,
misc tools.
I hope to buy a house with a three-car garage and walkout
basement workshop.
You haven't built an airplane until the project has been moved at least
once! |
| More
coming .............................. |
|
Photo: Dan Johnson