HilldaFlyer
Well-known member
Hello all FT Scratch Builders.
I would like to start this thread to complete a community build of the F/A-18 Super Hornet. There are lots of foamy designs out there, but I would like to have one for FT.
The goals of this build will be
I've done a lot of leg work to get this project started, so I'll just start by showing what I've done.
First, I've collected photos from the internet, and some really great profile layouts to form the basis for the general plane's shape. I'm pretty good with the computer, but it is still easier for me to print out something and draw on it to get the general idea of what parts are needed for a FT aircraft.
Here are some thoughts after drawing my proposed outlines:
The fuselage isn’t as wide as the prop hole needs to be - note that in the FT-22 the fuselage is way wider than “scale”. This may be why a lot of park jet plans have the motor hanging off the rear of the plane? Make the rear fuselage same width as the leading edge wing extensions to add strength to tail. I would like to allow for 7” propeller, the same power train that is on the FT-22.
The prop hole cuts a huge section out of the wing. We may need to add wing support like KF airfoils or CF rods (fly without to see). RCPowers always uses carbon tubes in his designs because Depron is not stiff enough on its own to support the forces of flight.
We'll have to see if a single layer of foam core is strong enough. If not, we'll have to use either KF airfoils which will double the wing thickness on LE or add carbon fiber tube by cutting open and hot glue rod in one thickness to keep weight down. Tape over cut. We will have to build one and see if carbon is needed.
My calculations from the sketch indicates we’ll need a 7” propeller to power the plane and an about an 8 inch propeller hole. This is for the same motor/prop as I have with the FT-22. If we use the outside of the fuselage as the outer limit of the hole, then I calculated that the wingspan would be 52” which is exactly twice the FT-22 at 26”. To get a plane down to 26” wingspan, we will need to widen the fuselage with respect to the wings, just like the FT-22.
If I alter the plans so that a 8" prop hole aligns with the point where the leading edge wing extensions meets the wing, then the wingspan needs to be 26.25” rather than 52”, only 0.25” longer than FT-22. This is doable.
The tail is skinnier than the leading edge wing extensions, so the fuselage under the wing will have to taper down or the tail will have to be wider.
With these thoughts, I dropped the image into Adobe Illustrator and traced out the parts that I would need. It was a lot easier than I anticipated. In one evening I had printable plans (of some sort)
It only took an hour to print, tape and cut out the 26 inch plane and it seems like it will work well without additional structural support on the wings...
This roughed out model does not have any contouring on the fuselage, I did it to see if the wings and fuselage would mesh and to see how the fuselage under the wing would work.
You can probably tell that I designed the under-wing fuselage to be shaped hourglass-like. I was also trying to get the engine intakes to be angled. After cutting it out several time I succeeded, as you can tell, but it was very complicated. I decided that to keep it simple for the FT beginners, we would need to come up with a "straight" design. We can put this design into the next more advanced build. The tapered fuselage would trap a lot of thrust right behind the prop with the skid plate in place. This is the main reason for changing to a straight design
I wanted to see if I put the propeller hole in the right spot, so I laid the electronics on the plane and held them in place with a little tape.
WOW! That make me happy!
Looks like it will balance with the motor and propeller in the forward part of the wing.
I altered the plans to make a two piece rear fuselage, one that extends from the point where the wing meets the leading edge wing extensions to the wing's trailing edge, and the other the same width as the tail that extends from the propeller slot to the tail.
Here is the inside fuselage pieces that extend from the tail to the propeller hole. The outside fuselage sides I decided to combine with the belly plate for added strength and support.
The belly plat has tabs that mount inside the propeller hole, so it looks like this when attached.
The prop hole doesn't have to be as wide on the belly plate, so I just cut it out to what I thought was a nice size.
The rest of the electronics were installed.
To mount the servos... I used little "nests". I know the Readi-Board peels really easily, so a little torquing and the paper lifts off the foam. This provides added stability to the servos.
The receiver is mounted in the rear, this way only one wire is snaked past that wire chopper called the propeller. The ESC is mounted in the body below the wing and the battery directly above the ESC. I had to use a 15 cm servo extension on the ESC to get it to reach the receiver.
I forgot to mention that the new design has a cockpit window bubble and a pointed fuselage. It is a little more advanced than simple, but it can be done.
Prototype #1 complete... This has a HK D2822 1450kv motor with a 7x6 propeller.
I would like to start this thread to complete a community build of the F/A-18 Super Hornet. There are lots of foamy designs out there, but I would like to have one for FT.
The goals of this build will be
- Use simple build designs familiar to FT for beginner builders.
- Have the same wingspan as the FT-22 (26")
I've done a lot of leg work to get this project started, so I'll just start by showing what I've done.
First, I've collected photos from the internet, and some really great profile layouts to form the basis for the general plane's shape. I'm pretty good with the computer, but it is still easier for me to print out something and draw on it to get the general idea of what parts are needed for a FT aircraft.
Here are some thoughts after drawing my proposed outlines:
The fuselage isn’t as wide as the prop hole needs to be - note that in the FT-22 the fuselage is way wider than “scale”. This may be why a lot of park jet plans have the motor hanging off the rear of the plane? Make the rear fuselage same width as the leading edge wing extensions to add strength to tail. I would like to allow for 7” propeller, the same power train that is on the FT-22.
The prop hole cuts a huge section out of the wing. We may need to add wing support like KF airfoils or CF rods (fly without to see). RCPowers always uses carbon tubes in his designs because Depron is not stiff enough on its own to support the forces of flight.
We'll have to see if a single layer of foam core is strong enough. If not, we'll have to use either KF airfoils which will double the wing thickness on LE or add carbon fiber tube by cutting open and hot glue rod in one thickness to keep weight down. Tape over cut. We will have to build one and see if carbon is needed.
My calculations from the sketch indicates we’ll need a 7” propeller to power the plane and an about an 8 inch propeller hole. This is for the same motor/prop as I have with the FT-22. If we use the outside of the fuselage as the outer limit of the hole, then I calculated that the wingspan would be 52” which is exactly twice the FT-22 at 26”. To get a plane down to 26” wingspan, we will need to widen the fuselage with respect to the wings, just like the FT-22.
If I alter the plans so that a 8" prop hole aligns with the point where the leading edge wing extensions meets the wing, then the wingspan needs to be 26.25” rather than 52”, only 0.25” longer than FT-22. This is doable.
The tail is skinnier than the leading edge wing extensions, so the fuselage under the wing will have to taper down or the tail will have to be wider.
With these thoughts, I dropped the image into Adobe Illustrator and traced out the parts that I would need. It was a lot easier than I anticipated. In one evening I had printable plans (of some sort)
It only took an hour to print, tape and cut out the 26 inch plane and it seems like it will work well without additional structural support on the wings...
This roughed out model does not have any contouring on the fuselage, I did it to see if the wings and fuselage would mesh and to see how the fuselage under the wing would work.
You can probably tell that I designed the under-wing fuselage to be shaped hourglass-like. I was also trying to get the engine intakes to be angled. After cutting it out several time I succeeded, as you can tell, but it was very complicated. I decided that to keep it simple for the FT beginners, we would need to come up with a "straight" design. We can put this design into the next more advanced build. The tapered fuselage would trap a lot of thrust right behind the prop with the skid plate in place. This is the main reason for changing to a straight design
I wanted to see if I put the propeller hole in the right spot, so I laid the electronics on the plane and held them in place with a little tape.
WOW! That make me happy!
Looks like it will balance with the motor and propeller in the forward part of the wing. I altered the plans to make a two piece rear fuselage, one that extends from the point where the wing meets the leading edge wing extensions to the wing's trailing edge, and the other the same width as the tail that extends from the propeller slot to the tail.
Here is the inside fuselage pieces that extend from the tail to the propeller hole. The outside fuselage sides I decided to combine with the belly plate for added strength and support.
The belly plat has tabs that mount inside the propeller hole, so it looks like this when attached.
The prop hole doesn't have to be as wide on the belly plate, so I just cut it out to what I thought was a nice size.
The rest of the electronics were installed.
To mount the servos... I used little "nests". I know the Readi-Board peels really easily, so a little torquing and the paper lifts off the foam. This provides added stability to the servos.
The receiver is mounted in the rear, this way only one wire is snaked past that wire chopper called the propeller. The ESC is mounted in the body below the wing and the battery directly above the ESC. I had to use a 15 cm servo extension on the ESC to get it to reach the receiver.
I forgot to mention that the new design has a cockpit window bubble and a pointed fuselage. It is a little more advanced than simple, but it can be done.
Prototype #1 complete... This has a HK D2822 1450kv motor with a 7x6 propeller.
