Ventus
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Update #1 - the Wings
Update #2 - Fuselage (part 1) | #2a | #2b
Original post:
I guess the title says it all
. Here's the concept drawing that I'll be using to design the parts:
The Goals
While I can fly basic aerobatics, I could use some inexpensive trainer to try to start transitioning into 3D flying. While the obvious route would be to build something like the FT 3D, I'd rather design something myself, while trying to find a way to make use of the heavy foam board that is the only kind available to me locally.
Still, building an FT 3D using the techiques described here should be interesting for comparng the weight with the FT board version, so i may just end up doing it at some time anyway.
So: the major goal is to try and keep the weight of the plane at 600 grams or under. I have weighed the motor and the electronics and I can already tell it's going to be a major challenge - they gross 274 grams (w/o servo wire extensions, hopefully I won't need those) meaning the complete airframe must weigh 325 grams or less. We'll see if that's even possible to achieve with the heavy board.
Here's the equipment: KEDA A22-15M (tried and tested, up to ~1000g of thrust with 9x6 to 10x5 prop), Turnigy Plush 25A ESC, Turnigy 1300mAH / 3s LiPo pack, Corona 8ch 35MHz receiver (I am still using my trusty 35MHz Optic 6), 4x Turnigy 8 gram servos (also tried and tested).
I'll be designing and drawing all the parts in Inkscape, so that if the plane flies well enough (and there's no reason to believe it won't) I will be able release the plans for anyone else interested in building it (it's a beautiful airplane and has perfect proportions for an RC model!). Even though the plans will be made for 5mm board, applying a slight adjustment while cutting should make them compatible with the 4.8mm Adams/FT/DT board as well.
Building technique
For the most part, I will be following standard FT building techniques. I will use the new, short version of the power pod (extracted from FT Simple Scout plans), FT control horns etc. The plane will be compatible with FT power packs - Pack B should be sufficient for regular flying, while Pack C should provide ample power for high performance aerobatics and possibly 3D.
However, there will be two major and important twists:
1.) The wing and the fuselage will be be built with the inside paper layer completely peeled off. Which means I will also be able to build a wing with a smoothly curved airfoil, using a relatively small amount of glue. For a few parts (like fuselage formers) the paper will be stripped on both sides and the foam reinforced with packing tape instead, but I don't want to overdo this technique (otherwise one might just as well go with depron instead).
The make of foam board I am using is basically equivalent to the Westfoam board which is 63% heavier than Adams/ FT board. Peeling off one layer of paper reduces the difference to about 20-22%, which is much more acceptable.
The tail surfaces are the difficult part, can't see a way to make them lighter other than stripping the paper off on both sides and replacing it with lighter one. This may be more viable once the plans are ready - it then might be an appealing idea to first color and then print out the plans and then glue them onto foam (i.e saving the weight on paint)
2.) As for the glue itself, I will be using UHU Por rather then Hot Glue - other than in a few places (like hinge reinforcement). I used it quite a lot in my Balrog build and I am very happy with it. The bond is very strong, clean and sparse application is easy, and the bonding time (10-15min) short enough not to be a significant problem. It doesn't have quite the strenghtening/stiffening qualities of hot glue, but the savings in weight are more important IMO.
That's it for the initial post I guess, will try and update as regularly as I can.
Update #1 - the Wings
Update #2 - Fuselage (part 1) | #2a | #2b
Original post:
I guess the title says it all
. Here's the concept drawing that I'll be using to design the parts:
The Goals
While I can fly basic aerobatics, I could use some inexpensive trainer to try to start transitioning into 3D flying. While the obvious route would be to build something like the FT 3D, I'd rather design something myself, while trying to find a way to make use of the heavy foam board that is the only kind available to me locally.
Still, building an FT 3D using the techiques described here should be interesting for comparng the weight with the FT board version, so i may just end up doing it at some time anyway.
So: the major goal is to try and keep the weight of the plane at 600 grams or under. I have weighed the motor and the electronics and I can already tell it's going to be a major challenge - they gross 274 grams (w/o servo wire extensions, hopefully I won't need those) meaning the complete airframe must weigh 325 grams or less. We'll see if that's even possible to achieve with the heavy board
.
Here's the equipment: KEDA A22-15M (tried and tested, up to ~1000g of thrust with 9x6 to 10x5 prop), Turnigy Plush 25A ESC, Turnigy 1300mAH / 3s LiPo pack, Corona 8ch 35MHz receiver (I am still using my trusty 35MHz Optic 6), 4x Turnigy 8 gram servos (also tried and tested).
I'll be designing and drawing all the parts in Inkscape, so that if the plane flies well enough (and there's no reason to believe it won't
) I will be able release the plans for anyone else interested in building it (it's a beautiful airplane and has perfect proportions for an RC model!). Even though the plans will be made for 5mm board, applying a slight adjustment while cutting should make them compatible with the 4.8mm Adams/FT/DT board as well.Building technique
For the most part, I will be following standard FT building techniques. I will use the new, short version of the power pod (extracted from FT Simple Scout plans), FT control horns etc. The plane will be compatible with FT power packs - Pack B should be sufficient for regular flying, while Pack C should provide ample power for high performance aerobatics and possibly 3D.
However, there will be two major and important twists:
1.) The wing and the fuselage will be be built with the inside paper layer completely peeled off. Which means I will also be able to build a wing with a smoothly curved airfoil, using a relatively small amount of glue. For a few parts (like fuselage formers) the paper will be stripped on both sides and the foam reinforced with packing tape instead, but I don't want to overdo this technique (otherwise one might just as well go with depron instead).
The make of foam board I am using is basically equivalent to the Westfoam board which is 63% heavier than Adams/ FT board. Peeling off one layer of paper reduces the difference to about 20-22%, which is much more acceptable.
The tail surfaces are the difficult part, can't see a way to make them lighter other than stripping the paper off on both sides and replacing it with lighter one. This may be more viable once the plans are ready - it then might be an appealing idea to first color and then print out the plans and then glue them onto foam (i.e saving the weight on paint)
2.) As for the glue itself, I will be using UHU Por rather then Hot Glue - other than in a few places (like hinge reinforcement). I used it quite a lot in my Balrog build and I am very happy with it. The bond is very strong, clean and sparse application is easy, and the bonding time (10-15min) short enough not to be a significant problem. It doesn't have quite the strenghtening/stiffening qualities of hot glue, but the savings in weight are more important IMO.
That's it for the initial post I guess
, will try and update as regularly as I can.
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