Knee building

Building the bubble headed booby

Knee building

Making the knees out of MDF.

MMMM MDF. Well I'll be laminating two 1/2
pieces of the stuff to get the one inch
height I'll need for each part. I'm using
Mark Thompsons plans for the size of these.

After you get done sanding glue two together
and clamp overnight. I use Elmers Probond wood
glue for what it's worth. Once your pieces are
dry rout them with a 45 degree bit. Sand any
imperfections and on to the next one.

All five almost done.

I cut the curves using my Rotozip. You can
see the pilot holes I drilled for the circle
cutter in each end of the wood. After you
cut out the curved parts clamp all ten pieces
together and sand. Make sure you where a
mask when you do this the MDF dust is nasty.

If you already have your tread boxes done and one
knee piece done. Don't fight the urge to put the
knee on top of the tread, stand back and GEEK OUT.
Inch by inch it's becoming a B9.

Making the hinges

First I printed the knee plan out from
my computer, Then I used a glue stick
to glue it to the 1/8" hardboard. I used
a jig saw to cut the pattern out.

getting there,,

Wood glue the two hinge pieces together.

With the buttons now in, I cut a 1" dia dowel

1/16 shy of 5/8 and rounded the edges. This

gets glued into the one inch hole. I got

tired of trying to find a 1" ID washer so

I just made one out ov PVC pipe shown here.

It's not really the right width but who

cares it looks cool. Super glue it down

around the dowel.

Then slip a 1" retainer ring around the dowel.
I think this one is a little bigger than 1", but
it's still a tight fit.

Heres the finished slot.

Heres another test fit shot. You'll notice that I
did not cut out the insides of the knees themselves,
I could not deal with any more cutting, plus they
add some weight to the tread sections now and a
nice stong platform for the rest of the B9.

After sanding both pieces I cut out my
center hole with a 1" spade bit then the
three other holes with a 3/8 bit.

I'm using 3/8 inch oak plugs for the rivets.
These have a very course grain so I'll smoosh
some wood filler into them.

PVC washer glued in place.

Ready for primer!

Pretty cool.

Heres where the 1/8 slot will go 1/4 from the edge. I did
the slot with my rotozip. The wood in the back is my guide.
This so far is the scariest thing I've had to do.

Heres a test fit. I still need to trim them down,
that will come once I install the top knee plate.

P.S I know it's upside down, I was just test fitting.