carrinsr
Jul 06, 2004, 02:21 PM
I hope some of you aircraft engineers/designers find this interesting enough to comment on, and offer suggestions (other than, "Stop! Don't build it!") :)
I've started on an 18' wingspan sailplane, my design. So far I've been working on building the center section of the 3-piece wing. The airfoil is a blown up version of the Sailaire (12 degree flat bottom). It is 24" from L.E. to T.E. The highest vertical point of the ribs is 3".
I'm using four each 3/4" I.D. roll wrapped carbon tubes, each 6' long, somewhat equally spaced apart, with a 6'-0" L x 3/8" T x 1" W Sitka Spruce spar above and below each carbon tube.
Cap strips will be made from 1/16" T, 3-ply plywood, grain vertical. I intend to fill in between the top and bottom spars (all around the carbon tubes) with light spackling compound. The entire wing will be covered with an outer skin of 1/64" T, 3-ply plywood. I weigh almost 300#, but think I could walk on these spars and not bend anything!
When I finish the center section I'll start building the two outer wing sections. I intend to build them using the same materials as in the center section, but with three 3/4" carbon tubes instead of four. The outer sections will taper from 24" to 18" along the T.E.
The outer sections will join the center section using three each 24" L x 3/4" O.D. carbon rods. Each outer section will have alerons, and the inner section will have flaps (one on each side of the fuselage, down angle to 90 degree). The entire wing will be flat (no dihedral/polyhedral).
I will start on the fuselage and tail section after I complete the wing. I used CorelDRAW to draw all the plans, then a local company plotted the drawing to scale for me.
When completed launching will be by tow hook, but will probably be done by car or truck instead of a winch. Not to worry...the local flying field is a touch-and-go airfield the Navy has kindly provided for our sailplane club, so the runways are l o n g , and lots of room on either side of the main runway.
OK...I'll admit...I've spent about a thousand dollars just for the materials for the wing - so far. I also realize there is probably a less expensive and perhaps lighter and stronger way to build the wing, given all the modern technology. But I'm an old die-hard balsa/ply fan who has been away from RC for over 20 years. However, I've been willing to include some of the more modern materials (i.e. carbon tubes and rods).
This sailplane has been a dream of mine for many years (almost from the beginning of my Sailaire flying days), and at age 64+ I don't want to turn back now. So please keep this in mind when you post your comments/suggestions.
I've included a photo of the center wing section in its current building mode.
THANK YOU for your comments/suggestions!
David
I've started on an 18' wingspan sailplane, my design. So far I've been working on building the center section of the 3-piece wing. The airfoil is a blown up version of the Sailaire (12 degree flat bottom). It is 24" from L.E. to T.E. The highest vertical point of the ribs is 3".
I'm using four each 3/4" I.D. roll wrapped carbon tubes, each 6' long, somewhat equally spaced apart, with a 6'-0" L x 3/8" T x 1" W Sitka Spruce spar above and below each carbon tube.
Cap strips will be made from 1/16" T, 3-ply plywood, grain vertical. I intend to fill in between the top and bottom spars (all around the carbon tubes) with light spackling compound. The entire wing will be covered with an outer skin of 1/64" T, 3-ply plywood. I weigh almost 300#, but think I could walk on these spars and not bend anything!
When I finish the center section I'll start building the two outer wing sections. I intend to build them using the same materials as in the center section, but with three 3/4" carbon tubes instead of four. The outer sections will taper from 24" to 18" along the T.E.
The outer sections will join the center section using three each 24" L x 3/4" O.D. carbon rods. Each outer section will have alerons, and the inner section will have flaps (one on each side of the fuselage, down angle to 90 degree). The entire wing will be flat (no dihedral/polyhedral).
I will start on the fuselage and tail section after I complete the wing. I used CorelDRAW to draw all the plans, then a local company plotted the drawing to scale for me.
When completed launching will be by tow hook, but will probably be done by car or truck instead of a winch. Not to worry...the local flying field is a touch-and-go airfield the Navy has kindly provided for our sailplane club, so the runways are l o n g , and lots of room on either side of the main runway.
OK...I'll admit...I've spent about a thousand dollars just for the materials for the wing - so far. I also realize there is probably a less expensive and perhaps lighter and stronger way to build the wing, given all the modern technology. But I'm an old die-hard balsa/ply fan who has been away from RC for over 20 years. However, I've been willing to include some of the more modern materials (i.e. carbon tubes and rods).
This sailplane has been a dream of mine for many years (almost from the beginning of my Sailaire flying days), and at age 64+ I don't want to turn back now. So please keep this in mind when you post your comments/suggestions.
I've included a photo of the center wing section in its current building mode.
THANK YOU for your comments/suggestions!
David