On Fri, 26 Dec 2008 21:12:22 -0800 (PST), "
wrote:

To All:

A couple of private messages commenting on the significant WEIGHT
difference between the big ribs, which weigh less than the little
ribs.

I believe the most significant difference is in the gusseting
material. The little ribs are gusseted with 1/8" doorskin material
whereas the big ribs use 'fiber' gussets... that is, heavy-grade of
CARDBOARD (as has been previously discussed). This rib is meant for a
PRIMARY GLIDER. Very low total weight and not much in the way of
forward speed. Plus, the big ribs are made of REDWOOD, each piece
selected for its light weight. The small ribs are meant for the wing
of a SINGLE-PLACE VW powered parasol. Other than for the methods of
rib construction, there is virtually nothing in common between the two
wings. The small ribs are made from much heavier PINE, and use
heavier wooden gussets.

-Bob

PS -- If you've comments, I'd appreciate you posting them here. It
isn't convenient to copy them from the blog area.

I've been away.
It looks to me as though the experimenting should continue (after the
morning hack up of course) the weights are pretty well on the money.

this all leads to a comment for the impecunious.
(impecunious = as poor as a church mouse )
I saw this commented years ago but never believed it at the time.
most people build the fuselage first because it builds quick. then it
gathers dust as the other bits get worked on and often the project
stops there because life's demands push the boring bits to the
background.

if you build all of your ribs first, and honestly they are a little
tedious, you still have the fuselage to go so the project has an
exciting bit ahead.this helps you get through the tedious bit.
in the case of the druine turbulent there are 20 ribs made from about
2 kilos of 6 x 9mm stripped up wood and ply ( about 4 and a half
pounds of wood) they are trusses made on a building board template.
you make one rib ready for gussets every day. so it amounts to a month
or so's work.
the cost is actually five eighths of stuff all because the techniques
of ignoring the knots and stripping up the wood that veedubber writes
about actually do work. you just cut away any part of a strip with a
knot and dont use it.
but in building your ribs you have actually assembled over half the
joints that will be made in the aircraft.

the benefits of getting on and doing your ribs first are that you
develop all your fine dexterity skills in woodwork that will be hidden
under the wing fabric. when you come to do the woodwork that will be
visible your skills and fluency with the techniques are just so much
more refined and practised.

you wouldnt think that building a rib could be done in too many
different ways but bob and I have totally different approaches to rib
making. bob's is a time honoured traditional method. my approach uses
no nails.

if anyone is actually interested I'll write up a narrative on how I do
them.

btw if anyone wants a copy of the druine turbulent plans I can share
legible photos of the plans gratis via email. I dont know that anyone
actually enforces copyrights on these plans. from australian
experience there is no money to be made from them and the plans
originators are more interested in seeing turbulents being built.
turbulents fly really well behind a converted 1600cc vw engine just
bolted straight to the firewall.
this works because the vw is an unbelievably smooth running engine.
from what I've read of bob's conversions to date he is doing a pretty
good job with them.

Stealth Pilot

(if you need to quantify what 'five eights of stuff all' means try
half of two tenths of a brass razoo's worth. it's a lot less than a
'penny for your thoughts' :-) )