An Affordable Homebrue 60 in DS machine

Hey All, I had some spare time on my hands on the weekend so I decided to cut up one of those TERMINATOR HLG ships on the Charles River site...
It went together so easy, cost me about $50 AUD total (excluding servers) and this thing fly's great, its always as high if not higher than my friends $380 HLG ship.
It got me thinking that if you can build a top performance HLG ship for next to nothing, why cant the same be done for a super strong, fast DS ship. Ive had a plane like this on the drawing board for some time now. Ive worked out the math's, put some dimensions together and done some rough plans up.
It needs to be a relatively straight forward build process. I.E.: Balsa/Ply built up fuse, Balsa tail feathers, foam core wing, sheeted with balsa/obechie with two spruce full length spars top and bottom.
I want it to be a plane that the average bloke can build. It doesn't need to perform as well as a $2000 glass/carbon ship but we're not trying to achieve that, we want to achieve a clean/fast/strong ship for a minimum cost without any problems or building hassles to run into.
We firstly define what we want the end plane to be like. The plane will not be a beginners plane, it will be for intermediate to advanced flyers, it will fly fast, rolls should be smooth, energy retention is one of the main goals we are trying to achieve. This thing needs to hold its energy incredibly well, we can achieve this by building the fuse to include a ballast tube and trying to keep a slippery low drag surface over the entire plane. If anyone disagrees stop me now.. Its true you probably cant make a fuse as slippery as a composite one with traditional methods but im sure there's not that much in it.
If anyone has any comments or wants to help contribute please reply to this post and we can start talking and throwing around ideas. Ive posted my original thoughts and calculations on the plane below. Ive got drawings of planform in cad aswell if anyone wants...
If it turns out to be a worth while plane I will be making a site about it with building photos, instructions, plans etc similar to the Terminator section on the Charles river site..
A quick planform drawing can be found at (
http://www.brisbane-events.com/planform_vtail.gif ) This shows the initial idea with the vtail. Im still not sure weather to go with the vtail or a conventional x style tail. For ease of building a conventional tail would be more practacle and can probably be built stronger as you could build it to the fuse sides where as a vtail kinda just gets glued ontop. Vtail has less drag and can sometimes be a little tricky to setup.
This is what ive got so far, let me know what you think of if anyone would be interested in building one as an online group project kinda thing..
General Info -------------------------------------------------------------------------------- Type: 1.5m Slope Racer optimised for Dynamic Soaring Controls: Ailerons, Elevator
Desired Flying Characteristics -------------------------------------------------------------------------------- Hold Energy Well (slipery, low drag surface) Hard turning ability (oversize elivator, good aileron throw) No Bad Stalling Habbits (good pick of airfoil) Good Penetrate (ballast tube) Great High speed handling (tight ridgid control surfaces)
Details -------------------------------------------------------------------------------- Wing Profile : RG15 Aspect Ratio : 9.246 Projected Weight : 850g Wing Loading : 324.516 g/sq ft (11.45 oz/sq ft)
Dimensions -------------------------------------------------------------------------------- Wing Span: : 1500 mm (60ins) Fuselage Length: : 900mm (36ins) Wing Planform : two panel semispan Wing Area : 243340 sq mm (377.17 sq ins) Mean Cord : 162.23 mm Root Chord : 191 mm Root Chord to first break : 490 mm First Break Chord : 165 mm First Break to tip chord : 220 mm (+ 40mm balsa tip) Tip Chord : 110 mm Dihedral Angle : 25 mm at tip TP Area : 36501 sq mm TP Aspect Ratio : 4.623 TP Mean Cord : 88.85 mm (3.49 ins) TP Span : 410.75 mm (16.17 ins) Elivator Area Required : 10950.3 sq mm Fin Area Required : 19467.2 sq mm Nose Length : 240 mm Tail Moment Arm : 573 mm
Calculations -------------------------------------------------------------------------------- Knowing That Wing Span : 1500 mm (60ins) Area Per Wing : 121670.0000 sq mm Total Wing Area : 243340 sq mm (377.17 sq ins) Projected Weight : 850 g
Wing Aspect Ratio = (wing span * wing span / wing area) 1500 * 1500 = 2250000 / 243340 = 9.246
Mean Chord = (span / aspect ratio) 1500 / 9.246 = 162.23 mm (6.38ins)
Wing Area = (span * mean chord ) 1500 * 162.23 = 243345 sq mm
Wing Loading = (weight / (wing area in inches/144)) 850 / (377.17/144) = 324.516 g/sq ft (11.45 oz/sq ft)
TP Area = (wing area * percent tailplane area Require) 243340 * 0.15 = 36501 = 36501 sq mm
Elivator Area Required = (20% - 30% tailplane area) 36501 * 0.3 = 10950.3 sq mm (16.97 sq ins)
Fin Area Required = (6% - 8% of wing area) 243340 * 0.08 = 19467.2 sq mm (30.17 sq ins);
TP Aspect Ratio = (wing aspect ratio x (50% - 60% of wing aspect ratio)) 9.246 * 0.5 = 4.623 TP Mean Cord = (sq. root of (TP area / TP aspect ratio)) sq root of (36501 / 4.623) = 88.85 mm (3.49 ins)
TP Span = (TP aspect ratio x TP mean chord) 4.623 * 88.85 = 410.75 mm (16.17 ins)
Nose Length = (1.25 x wing root chord) 1.25 * 191 = 238.75 = 240 mm
Tail Moment Arm = 3 x Wing Root Chord = 3 * 191 = 573 mm
Fuselage Length = 900mm (36 ins)
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