Below: The original 32 ribs show consistent results that
are easily achievable using this technique. Now the
author needs to do it all again to fill for a solid cowl!
With infill pieces in place and lightly
sanded, the cowl is ready for covering.
The same technique produced the
upper wing ribs. The spinner?
Well, that’s a story for
Above: A notch in the
small scrap of walnut
effortless sizing for
each of the cowl
ribs. Slicing the 96
pieces the author
ultimately needed went
cut, I opted to use plywood for its
increased durability to guide the scalpel
blade, instead of a piece of card stock or
template to a
walnut strip allowed
me to reference
against both the balsa
stock and a drafting
triangle clamped to my
cutting mat. I taped the balsa to
the triangle, and carefully ran my
scalpel around the template
for the first cut. Note
that I am left-handed,
so most of you will
want to mirror my
layout if you try this
The only remaining
trick is accurately spacing
the template for each slice.
The photos show a small scrap of thin
walnut, with a slight notch in one corner.
This notch matches the desired rib
depth. After the first cut, I positioned
the notch against the balsa stock,
I soon had the required ribs and several
I’ll readily admit to starting down
this road without fully knowing
my plans for the cowl.
Although the framed
results were quite
satisfactory, I couldn’t figure out how to
get 32 pieces of tissue to span those ribs
and have them look as pretty as Tom’s
solid cowl. I finally admitted defeat; a
solid cowl was the only option. So how
do I get from here to there?
I chose to fill in between the ribs using
a secret stash of 4.1-pound balsa that
I had been saving for the right project.
The gaps tapered slightly
90 Model Aviation SEP TEMBER 2016
AROUND THE PATCH