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Swappable Trainer

#1
Hello all! First thread in this forum :)

I have been building the FT Flyer and is waiting on good flying weather in Sweden. So I hade some time over and though that I should try to build a trainer based on the swappable fuselage. I have done a quick CAD design to get the measurements and Idee if it will fly.

My questions are:
Will it fly?
Will it any good?
What would you change?

FT Trainer.jpg FT Trainer - top.jpg

I have tried to find information about general airplane building. Length between wing and stabilizer, wing size etc. So if any one have any good thread or site can give advise of general building specifications.

Regards
Torbjörn Blom
 
#3
Yeah I think I'd consider deepening the wing chord to around 200mm and the ailerons to around about 30mm. Other than that it should be a fun flier. The elevator will have stacks of pitch authority and with added wing area it will waft around quite nicely!

Excellent design, I'd build one for sure :D
 
#4
Thanks for all the answers!
I have tried to incorporate both your advise. The largers sheet of foam I have is one meter wide so that my wing.
I have also extended the wing chord to 16mm and enlarge the aileron to 30mm. Offcoars will I need to reinforce the wing with carbon fiber. I have a plan to make a old school reinf on topp of the wing.

Do any one have an idea how to put servos for the ailerons? The quickest way must be to put them in the wing they will only protrude 1mm on each side because I use 5mm thick sheets.

Some new drawings:
FT Trainer.jpg FT Trainer - top.jpg
 

pgerts

Old age member
Mentor
#6
I think that you might need a longer nose, but that might be wrong as you have 100 mm in front of the wing to put the battery.
The plane appears to be tail heavy when looking?

The aileron servos are best positioned in the centreline of the ailerons to transfer the force as good as possible without getting the aileron to bend. With 2 servos you can get flaperon/spioleron.

Vi har alltid fint flygväder i sverige.
 
#7
I agree - the nose could live with being out a bit longer. You're looking for around about 30% of the wing chord from the leading edge as a CG.
 

Ak Flyer

Fly the wings off
Mentor
#8
The rear stabilizers are quite large with small control surfaces. I think it will not respond very well and with such a narrow wing chord it's going to have to be fast. I would reduce the size of the vertical and horizontal stabilizers and up the control surfaces a bit. Make the wing wider (chord) and longer (span) or at least wider. Also, some dihedral in the wing (just a bit) will stabilize it a lot. The horizontal stabilizer should also be in the same plane as the wing, not under the tail. That will also help protect it from damage during landings.
 
#9
I think you'd be surprised at the control that you'd get out of that elevator. Keeping in mind that there isn't a huge amount of mass to lift I don't think that it's too far off but I'd agree, a little more chord on the wing will go a long way.
 
#10
Updated again with your input. It looks more like a fun bat every time :)
I have moved the elevator in the the, this is one big sheet now. Wing chord is extended to 200mm. Ailerons are still 30mm wide.
What do you think now? I think it will have ton of lift with that wide wing and some nice slow fly qualities.

FT Trainer.jpg FT Trainer - top.jpg
 
#13
I might go get some foamboard from the craft shop and give it a shot this weekend if I have the time. Looks like it could be a bit of fun :D Nice effort!
 
#14
God to hear that you think it will FLY!
I think till will be more sturdy with one big sheet of foam board and it will go faster to build. I will try build one this night but it will take a few sessions before I am done. I will keep you informed.
 
#15
I have done a drawing for the parts that needs to be cut except the own from Flite test.
It is drawings for the wing + additional KF step and the fin.

This drawing is for my own use and it might needs to be updated when I have seen it fly. But this is what I will build after. Picture is not correct size, use PDF for correct size.
FT Trainer - cut-out.JPG
 

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