Curt Stevens "Legacy" glider is an 18 inch wingspan 4 inch cord, 1/4 inch thick. The Stabilizer is 6 inches wide by 3 inches.
Favorite Quotes
"Your HLGs should be made to fly, not to survive a crash. The crashes are you own fault. When a model survives a crash you should reexamine your design. Are you building airplanes or tanks ?"
Hand launch Glider
According to Curt Stevens Curt Stevens, he is full of hubris, but I learned more from Curt on building hand launched gliders. Than I learned from any other hand launched glider article I've ever read.
https://web.archive.org/web/20060316164535/http://www.modelresearchlabs.com/legacy.htm Curt Stevens,
"These HLGs actually are fairly simple but must be very precise in construction and adjustment."
"In order to become a competitor in the Hand Launch Glider event you must strive to avoid poorly designed models, poorly built models, poorly adjusted models and bad air."
"The stab is of the sweepback leading edge type so it will never flutter off on any high-speed launch."
"Smaller rudders will always thermal best, but a larger rudder is required for the launch phase. Short low aspect ratio rudders are the best compromise as they will provide the necessary directional stability in launch and perform as a smaller area rudder in the glide. Tall high aspect ratio rudders are bad as they are too effective in the glide and will encourage thermal spin out. Exact rudder size is a function of your launch style. I expect you to take a pair of scissors and trim the top off the rudder until you find the minimum size that fits your individual launch characteristics."
"The stab is mounted 5/8 of an inch below the wing. This is the correct dimension for a 16-18 inch wing with a 4-inch chord."
Hand Launched Glider construction equipmentItem 1; you must have a piece of glass to build on. a piece at least 12"x 18" and a larger piece would be better. 18" x 30" x ΒΌ" thick. This is used to cut on, sand on, and as a surface plate when building.
Item 2; You must have a dihedral jig. We need to be able to consistently build straight airplanes every time . You cannot tolerate a crooked flying airplane; all dihedral joints must always be absolutely parallel . Crooked airplanes are sometimes impossible to adjust. And crooked airplanes do not fly well.
Item 3; You will need a good quality-drafting triangle.I prefer a 30-60 that is about 10 or 12 inches on the hypotenuse side. You should treat this as a deposable tool and replace it when it gets ragged.
Item 4; A razor plane is an absolute must. "Solingen" made in Germany.
Item 5; A supply of good quality carbon steel double edge razor blades.or X-ACTO #11 blade. with A zirconium nitride coating or carbon steel.
Item 6; Single edge razor blades. The standard hardware store variety is good .
Item 7; A scale to weight with. Most people prefer the digital scale.
Item 8; Sandpaper. "Norton" tan colored paper.
Item 9; A metal sanding block,Great Planes 11" Easy-Touch Bar Sander. glue the sandpaper to the block, I use 3M's # 77 spray can contact cement. When the paper is worn out, peel it off and use "Goo Gone" to remove the glue.
Item 10; You will need a set of outline templates for the glider design you are building. 1/32 clear plastic. With good templates all you need to do is place the template on the wood in the best possible location with the grain correct for the surface That should be all the tools.
Hand Launched Glider constructionwith some comments of my own
https://web.archive.org/web/20060316164603/http://www.modelresearchlabs.com/detailed_finishing_of%20HL_Gliders.htmCurt Stevens doesn't give you any information on how to shape the wing. He starts his article on how to apply the finish. He sold a line of finish products on his website, so this must be the reason he is obsessed with the finishing process.
JIM BUXTON , less finishes is more page 15 still overkill, talcum powder is real heavy.
https://indoornewsandviews.files.wordpress.com/2012/10/inav-113.pdf Everyone has their own opinion, so here's mine. Your method of glider finish depends on your venue. Indoor gliders cat I & II don't require any finish at all, it adds weight. If you need to add weight by applying the finish to reach the ceiling, you should have built a stronger glider.
Outdoor gliders only need enough finish to keep them from absorbing water. Thicker finishes shrink more and cause warping. Why spend excessive time with the finish when success with outdoor gliders is launching them into a thermal.
Here's Curt Stevens, he is full of hubris, but I learned more from Curt on building hand launched gliders. Than I learned from any other hand launched glider article I've ever read.
All finishing must be done on a clean glass top work table. It is also a real good idea to do all your construction on a glass surface to avoid problems later.
Polydihedral, stand the wing on its trailing edge on the clean sheet of glass. Rest the edge of a plastic drafting triangle on the glass surface and press it up against the bottom of the wing. Slide the triangle along the wing to the one of the dihedral breaks. Hold the triangle tight against the wing and place the wing flat on the glass surface, now with a sharp new razor blade, make a nice clean cut into the wing. Do not cut all the way through . Make multiple cuts.. Repeat this process for the other two dihedral breaks. It is extremely important that all three dihedral breaks be absolutely parallel. Any error at this point means that you are building a crooked airplane. Later I improved on Curt's method. Dihedral glue up jig, builders plan gallery HPA.
Never, never ever glue the fuselage on crooked. There is no such thing as gluing the wing on crooked, the wing is the part that does the flying. What you would be doing is gluing the fuselage on crooked and dragging it sideways thru the air forever after.
The rudder should be finished just like the wing. The trick here is to cut the outline of the rudder on the end of a balsa sheet and completely finish the rudder before parting it off the balsa sheet.
Tail feathers with a reasonably low aspect ratio, and most importantly, 15 degrees of sweepback on the leading edges, will not flutter and blow off on the lanch.
Trim the fuselage to fit the stabilizer Those who have to warp up or down into the stabilizer are just sloppy builders. I use a simple tool that is a piece of .025 thick aluminum about 1-1/2 inches wide and 18 inches long. I have scribed a series of parallel lines 4 inches long near one end. These lines are spaced every .050 inch. Hold this tool against the fuselage and against the bottom surface of the wing in a position so that the little lines are where the stab needs to be glued on. and trim the stab mounting area so that it fits the bottom of the stab parallel and 0-0 to the wing. Yes I did make one of these aluminum bars, but then I discovered cheap plastic rulers have parallel lines on them. Also 0-0 is not the setting that you want. It varies depending on how much Phillips entry you have on the wing, if any.
To glue the stab on place it flat on a building board with grid lines, place the fuselage in the correct position on the stab. Stan Buddenbohm recommended using stick glue, then adjusting stabilizer tilt before using cyanoacrylate.
My glider finishing processes is different than Curt Stevens.
The Bottom of the wing should be flat. Before you start shaping top surface. On a piece of glass, spray glue to sheets of 220 grit sandpaper end to end. With the bottom of the wing on the sandpaper, and a sanding block on the top surface sand the bottom of the wing flat. Then shape the airfoil.
For medium and high ceiling gliders and all outdoor gliders, you should apply a very sparse coat of sanding sealer to the soft light wood and this keeps the second coat of sealer from penetrating into the wood causing excessive weight. Wiping sealer on to the wood and wiping it off doesn't achieve our objective of adding the least amount of finish possible. You can't control the amount of finish by Brushing on thin 50/50 coats of sanding sealer. It soaks into the balsa wood. By trying all these different methods and keeping records of the weight gain. I was concerned of just how much weight was added to the wing. The solution I came up with was to use aerosol cans of sanding sealer and not spraying full coat, but using a fast motion and just spritzing on the lightest amount of sanding sealer and then quickly brushing the surface with a damp with lacquer thinner 3/4" wide fine bristle artist paint brush, to even out the sanding sealer. The sanding sealer dries within 20 minutes enough to sand with 320 grit sandpaper. Using the same method, spray on the second coat & sand with 400 grit sandpaper. This method produced the least amount of weight gain, thin enough that it doesn't cause warps when dry, yet I have had gliders in a pond for 20 minutes before I could retrieve it, without warping, even the tail surfaces. In fact, this glider went OOS in a thermal the next day.
More from Curt Stevens. If you can take it.
HAND LAUNCH GLIDER AIRFOILS part 1
https://fullsizeplans.com/images/nffs/HLG%20Airfoils%20Part1.pdfHAND LAUNCH GLIDER AIRFOILS part 2
https://fullsizeplans.com/images/nffs/HLG%20Airfoils%20Part2.pdf Bob
