Grant
August 8th 03, 03:52 AM
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)
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)