FTFC20 Opel Rak 1 designed by Dr. Looping Looie
- Thread starter Dr. Looping Looie
- Start date
Dr. Looping Looie
Elite member
The video is done!
Its a gentle flyer, and it flyes pretty much on its own. Its extreamely stable on the pitch axis, but it hates wind and turbulences. On a windless day, thing will land on its own. Some of the landings in the video were made without touching the elevator.
Its a gentle flyer, and it flyes pretty much on its own. Its extreamely stable on the pitch axis, but it hates wind and turbulences. On a windless day, thing will land on its own. Some of the landings in the video were made without touching the elevator.
bracesport
Legendary member
very impressive flying - gentle she certainly is - nice! 
TooJung2Die
Master member
It flies great. I think you were too critical of the glide. It may not have the glide ratio of a sailplane but as you demonstrated it is perfect for greasing a landing! I think you have a serious contender. You have a good looking balsa to foam board conversion. Bonus point for being a nice scale model of a full size aircraft. Another bonus point for an airplane that will practically fly itself and doesn't need great skill to keep airborne.
L Edge
Legendary member
Well done. This candidate should raise the eyebrows on the judges!!!!!
When you watch the video, it is impressive the way it flies. You can see it is stable in the total flight environment from launch to landing. Your approach in trying to keep it light really shows on the landings and slow flight!!!! Your design of the wing is better than using 2 carbon rods across the wing.
If you like engineering problems, see if you can adapt the plane to a small Estees rocket. I did a Bell X1 rocket plane which was successful from shifting CG(as it burns) to stress problems to firing off. Worst it could do for you is to have a meltdown of your plane.
That would be a fun project for you.
Again, excellant choice for your entry.
When you watch the video, it is impressive the way it flies. You can see it is stable in the total flight environment from launch to landing. Your approach in trying to keep it light really shows on the landings and slow flight!!!! Your design of the wing is better than using 2 carbon rods across the wing.
If you like engineering problems, see if you can adapt the plane to a small Estees rocket. I did a Bell X1 rocket plane which was successful from shifting CG(as it burns) to stress problems to firing off. Worst it could do for you is to have a meltdown of your plane.
That would be a fun project for you.
Again, excellant choice for your entry.
Very nicely done! Another success from the doctor!
Dr. Looping Looie
Elite member
Thanks guys for all the great response
Dr. Looping Looie
Elite member
Quick little update:
Im done with the plans and its ready for release! Im just waiting for better weather.
If you plan on building on, here is a little useful info:
To build it, you need a little over 2 sheets of foam, 3ch radio and reciever, F-pack spec motor and ESC combo, 5" or smaller props, 3s 1200mAh Battery, 3 servos and very importantly some very light wooden sticks. I found the wood on fireworks rockets to work just fine. We also had some fun with other parts from the rocket...
This build is very different from a standard FT build, but that doesnt mean its complicated. If you work carefully and get your angles right, it will come together on its own. Theres a lot of improvisation needed, so maybe not a first build.
Flying wise it flyes pretty much on its own. BUT only if its calm weather! This thing hates turbulences! So keep that in mind if you want to build it. But other than that it flyes pretty good. Its a stable cruiser that can do some interesting loop maneuvers but has a lazy roll axis. It can deliver enjoyable glides but also some action. Gliding wise, its not a high performance glider and gets outperformed by a tiny trainer easily. It doesnt travel far distances, but once its high up in the air, it can stay there for quite some time.
Its super easy to handle, and can easyly be a beginners second airplane. It might be a little too fragile to be a first plane, but in all the flights ive done with it, there was never a critical situation such as stall.
The looks in the air are very scale and it doesnt appear like a foamboard build. Downsides are that its hard to put your electronics in and that you dont have access to everything very easily because of scale.
Anyway, if your interested, plans come around this week, so stay tuned. Im also going to upload some detail pictures so that its easyer to build.
Im done with the plans and its ready for release! Im just waiting for better weather.
If you plan on building on, here is a little useful info:
To build it, you need a little over 2 sheets of foam, 3ch radio and reciever, F-pack spec motor and ESC combo, 5" or smaller props, 3s 1200mAh Battery, 3 servos and very importantly some very light wooden sticks. I found the wood on fireworks rockets to work just fine. We also had some fun with other parts from the rocket...
This build is very different from a standard FT build, but that doesnt mean its complicated. If you work carefully and get your angles right, it will come together on its own. Theres a lot of improvisation needed, so maybe not a first build.
Flying wise it flyes pretty much on its own. BUT only if its calm weather! This thing hates turbulences! So keep that in mind if you want to build it. But other than that it flyes pretty good. Its a stable cruiser that can do some interesting loop maneuvers but has a lazy roll axis. It can deliver enjoyable glides but also some action. Gliding wise, its not a high performance glider and gets outperformed by a tiny trainer easily. It doesnt travel far distances, but once its high up in the air, it can stay there for quite some time.
Its super easy to handle, and can easyly be a beginners second airplane. It might be a little too fragile to be a first plane, but in all the flights ive done with it, there was never a critical situation such as stall.
The looks in the air are very scale and it doesnt appear like a foamboard build. Downsides are that its hard to put your electronics in and that you dont have access to everything very easily because of scale.
Anyway, if your interested, plans come around this week, so stay tuned. Im also going to upload some detail pictures so that its easyer to build.
Dr. Looping Looie
Elite member
Here are some of the details:
I changed the ailerons, originally, there was no paper on them. Now, the ailerons are much more responsive because of less flex.
You can see that the wood goes all the way forward. The wing struds are Just glued on.
The cables go into the fuse through this hole. I recommend glueing them down to keep them out of the way of the prop. Also the powerpod friction fits in there. Since its a pusher it wont fall out.
Thats how the tail is mounted.
I was lazy and just glued the servos on. If you want to hide them inside the wing, Install them before you put your bottom plate on.
I changed the back landing skid support to this wood piece to form a hook for launching. Extreamely fun!
Be careful when gluing your tail struds on, they could get in the way of the prop. This plane can take a maximum of 5" props.
Its important to put a beat of glue on the part where the two wings join together to protect it from delamination.
The pilot is secured by two pieces of velcro on the sides.
View into the cockpit. You can see the "battery hatch" in the front.
The battery must go all the way forward, and this part prevents it from moving backwards.
Of course you could hide the electronics much better in there, but I was just lazy, and you cant really see it in the air, so who cares.
Right now, theres terrible wind, but once it calms down im going to make a video with rocket and tow launches, and then im going to release the plans with it.
I changed the ailerons, originally, there was no paper on them. Now, the ailerons are much more responsive because of less flex.
You can see that the wood goes all the way forward. The wing struds are Just glued on.
The cables go into the fuse through this hole. I recommend glueing them down to keep them out of the way of the prop. Also the powerpod friction fits in there. Since its a pusher it wont fall out.
Thats how the tail is mounted.
I was lazy and just glued the servos on. If you want to hide them inside the wing, Install them before you put your bottom plate on.
I changed the back landing skid support to this wood piece to form a hook for launching. Extreamely fun!
Be careful when gluing your tail struds on, they could get in the way of the prop. This plane can take a maximum of 5" props.
Its important to put a beat of glue on the part where the two wings join together to protect it from delamination.
The pilot is secured by two pieces of velcro on the sides.
View into the cockpit. You can see the "battery hatch" in the front.
The battery must go all the way forward, and this part prevents it from moving backwards.
Of course you could hide the electronics much better in there, but I was just lazy, and you cant really see it in the air, so who cares.
Right now, theres terrible wind, but once it calms down im going to make a video with rocket and tow launches, and then im going to release the plans with it.
Dr. Looping Looie
Elite member
Crashed it today...
It was a lot of wind and I Made a rope launch, there was too much stress at the airframe and it snapped in mid air and looked completely epic! Parts flew all over the field!
Sadly, it wasnt captured on camera...
But I think I can fix this easyly.
It was a lot of wind and I Made a rope launch, there was too much stress at the airframe and it snapped in mid air and looked completely epic! Parts flew all over the field!
Sadly, it wasnt captured on camera...
But I think I can fix this easyly.
TooJung2Die
Master member
Ouch. High start and bungee launches are very hard on an airframe. Hope you get it flying again soon.
Dr. Looping Looie
Elite member
Its already back together in one piece. Wings and tail section were fine, so it was just a bit of glueing.
Dr. Looping Looie
Elite member
100 km/h of airspeed, a high lift airfoil and a plane connected to the ground was not the smartest idea...
But it looked totally awesome!
If you see the video, you know why it crashed.
But it looked totally awesome!
If you see the video, you know why it crashed.
Dr. Looping Looie
Elite member
Its already back together and ready to take off into the skies again!
Dr. Looping Looie
Elite member
Hello folks!
I finnaly managed to complete the plans and also made another video!
Happy building and have fun!
I finnaly managed to complete the plans and also made another video!
Happy building and have fun!
Vimana89
Legendary member
Looks like a lot of fun. The nose-up tendency is nice for beginners, not the type of plane usually meant to be good for inverted anyway. My Floating Kidney can glide and do simulated dead stick landings, stop and restarts, and on 4ch with elevons and a rudder it rolls as good as it loops, but obviously as a low aspect design is a lot less stable and "hands-off" of a flying experience, where yours is rock steady. It is the only plane of mine that has any real glide ratio though. That wing folding looked painful, guess the plane really doesn't like wind!
. The nose-up tendency is nice for beginners, not the type of plane usually meant to be good for inverted anyway. My Floating Kidney can glide and do simulated dead stick landings, stop and restarts, and on 4ch with elevons and a rudder it rolls as good as it loops, but obviously as a low aspect design is a lot less stable and "hands-off" of a flying experience, where yours is rock steady. It is the only plane of mine that has any real glide ratio though. That wing folding looked painful, guess the plane really doesn't like wind!
L Edge
Legendary member
Got a experiment if you want to try. Remove any excess weight(pilot, etc.) and reset CG, I think you have an excellant soarer to explore with your plane.
When you have good winds, fly the plane to say 400ft.(higher up the flows are faster and less gusty). Shut engine down and try to soar. You can stay up for long periods of time when the proper CG matches the winds. You will have to match the CG movement to the speed of the winds. That will take some experience and also setting the deflections of your controls.
The camber on your wing is a likely candidate.
I use to show the student pilot's that wind is your friend. Just go up to a good height, shut the engine off their trainer and with the right placement, soar and it usually blows their mind that their trainer can do that.
I used a camber wing on my transport to really improve the lift.
When you have good winds, fly the plane to say 400ft.(higher up the flows are faster and less gusty). Shut engine down and try to soar. You can stay up for long periods of time when the proper CG matches the winds. You will have to match the CG movement to the speed of the winds. That will take some experience and also setting the deflections of your controls.
The camber on your wing is a likely candidate.
I use to show the student pilot's that wind is your friend. Just go up to a good height, shut the engine off their trainer and with the right placement, soar and it usually blows their mind that their trainer can do that.
I used a camber wing on my transport to really improve the lift.
Matthewdupreez
Legendary member
is there any way i can fit a 6' prop onto this?
i really want to build it but i only have a 6' prop...
i really want to build it but i only have a 6' prop...
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