Hi - fascinated by your tandem wing project. I studied a tandem wing airliner for my Masters in the '70's; and now that I've retired I've built a Bert Streigler Delanne D200 (featured in the September 1981 Radio Control Models and Electronics magazine). I would point you at the Miles M35 & M39 Libellula designs, and also Maurice Delanne's designs. A key feature of the Delanne designs is the wing separation. The front wing is always larger than the rear wing to ensure that the downwash does flow over the rear wing. This in turn also ensures that the front wing stalls first and the aircraft pitches nose down The Arsenal Delanne 10 C-2 had a top speed of 345 MPH and landed at 45 MPH!! My D200 has some handling quirks in the it rolls out of loops and also in any inverted flight it rolls out the other way!! Take-offs are very squirrelly too. The control system is elevators on the rear wing and ailerons of the from wing. The next steps are an elevon control system and possibly a gyro stabiliser. John B
I am working on something similar, but I have an important question, did you use the forward wing with ailerons and the rear wing with elevators, or the other way around? Because what I have found out is the bigger wing should have ailerons, is that matching your experience? Thanks in advance for your reply. Btw, I really like that chill/hobby mood that I can feel in the video. Thanks. Mark.
Thx! I’m glad you enjoyed it. On the initial builds I used elevator up front on the small wing and ailerons on the larger rear wing. This worked well but led to a strange roll-pitch coupling in the controls. It wanted to pitch up when I rolled in either direction because the ailerons are behind the Cg. I ended up configuring it with elevons front and rear. This got rid of the pitching because the aileron moments were on either side of the Cg. It also helped with pitch controls because I could use less throw on the elevators because there were front and back. Hope that helps.
@@DefiantWings Thanks for replying, so you had ailerons in the rear one and elevators in both? How did you manage that with only 4 control surfaces, as visible at 0:52? Sorry for asking again, but I thought after so much experience with tandem wing, that you got, you could help me out :), thanks.
@@DefiantWings after you experience with tandem wings Would you think a tandem wing glider would be superior to the normal gliders that are 20 meters wing span? It will definitely half the wing span but i am not sure if it will provide the same gliding control and stability Also what would you say are the main drawbacks of the tandem wing?
@@FirstLast-tx3yj A tandem wing would make an interesting glider but it would never be as efficient at a traditional glider. While tandem wing designs certainly do reduce the overall wing span they don't cut it inn half. There are several areas where aerodynamic losses creep in to a tandem wing design. the rear wing is always in the downwash of the front wing. this reduces the efficiency of the rear wing. The 2 wings, even if identical, don't see the same wing loading and thus do not have the same angle of incidence. One of them will always be at a less efficient AOA. You also double the number of wing tips and induced drag. One of the advantages to a tandem wing is that you get the advantages of a long, high AR wing with less span. Not half the span, but defiantly less. Because the span is less it is a lot more agile in role. It is also more stable in pitch. I chose the configuration because I could move the CG to the center of the fuselage for a VTOL design. I am currently working on a larger version as a single motor pusher with a 54" wingspan.
Cool project, really nice work, (subscribed). Do you have any thoughts on putting the back wing lowwer than the front wing?, I have seen some stuff around it creating greater separation when AOA increases.
Thx! I have looked briefly at staggering the wings, not high and low in the back. Lowering the rear wing gets a little complicated in that the down wash from the front wing starts to interact and lowers the effective AOA. At higher AOA the effect can change. I wanted to start with something easier to model and make sure that my results matched the aerodynamics of the model. Lower wings complicate the VTOL implication as well and I wanted to keep my first composite build as simple as possible. I would like to build a few foam test planes with different wing configurations and compare them in flight
That’s a good question. It seems there are a lot of answers. For me, if the forward wing operates like a horizontal stabilizer, as a control surface, I consider it a canard. If it generates an appreciable proportion of the lift, I consider it a tandem. I haven’t seen an official definition.
Great invention & blog diary 📔. Try omnidirectional thrusters. Btw planes land & don’t usually crash. That’s why planes don’t crash too well. Good luck 🍀 & take care
Hi - fascinated by your tandem wing project. I studied a tandem wing airliner for my Masters in the '70's; and now that I've retired I've built a Bert Streigler Delanne D200 (featured in the September 1981 Radio Control Models and Electronics magazine). I would point you at the Miles M35 & M39 Libellula designs, and also Maurice Delanne's designs. A key feature of the Delanne designs is the wing separation. The front wing is always larger than the rear wing to ensure that the downwash does flow over the rear wing. This in turn also ensures that the front wing stalls first and the aircraft pitches nose down The Arsenal Delanne 10 C-2 had a top speed of 345 MPH and landed at 45 MPH!!
My D200 has some handling quirks in the it rolls out of loops and also in any inverted flight it rolls out the other way!! Take-offs are very squirrelly too. The control system is elevators on the rear wing and ailerons of the from wing. The next steps are an elevon control system and possibly a gyro stabiliser. John B
I will be following! I built a tandem tilt wing vtol, 2 motors per wing. Currently testing in hover, quad mode now.
That’s awesome! How is you testing going? Do you have any videos of it posted?
can we buy them or fund yall
Always love to see your thoughts and different iterations as they progress.
Thx! I’ve adopted the SpaceX philosophy of ‘Test early, Test often’. So I’ve been testing with the cheapest viable test articles…
I am working on something similar, but I have an important question, did you use the forward wing with ailerons and the rear wing with elevators, or the other way around? Because what I have found out is the bigger wing should have ailerons, is that matching your experience? Thanks in advance for your reply. Btw, I really like that chill/hobby mood that I can feel in the video. Thanks. Mark.
Thx! I’m glad you enjoyed it. On the initial builds I used elevator up front on the small wing and ailerons on the larger rear wing. This worked well but led to a strange roll-pitch coupling in the controls. It wanted to pitch up when I rolled in either direction because the ailerons are behind the Cg. I ended up configuring it with elevons front and rear. This got rid of the pitching because the aileron moments were on either side of the Cg. It also helped with pitch controls because I could use less throw on the elevators because there were front and back. Hope that helps.
@@DefiantWings Thanks for replying, so you had ailerons in the rear one and elevators in both? How did you manage that with only 4 control surfaces, as visible at 0:52? Sorry for asking again, but I thought after so much experience with tandem wing, that you got, you could help me out :), thanks.
Originally I had elevators in the front and ailerons in the rear. I now have Elevons front and rear. So, combined elevator/aileron front and rear.
@@DefiantWings Thank you, sir! Have a good day.
My pleasure, any time. Good luck with your build.
Version 2 is beautiful. Any plans?
Thx! These are all one-off prototypes so I don’t have plans for them
@@DefiantWings after you experience with tandem wings
Would you think a tandem wing glider would be superior to the normal gliders that are 20 meters wing span?
It will definitely half the wing span but i am not sure if it will provide the same gliding control and stability
Also what would you say are the main drawbacks of the tandem wing?
@@FirstLast-tx3yj A tandem wing would make an interesting glider but it would never be as efficient at a traditional glider. While tandem wing designs certainly do reduce the overall wing span they don't cut it inn half. There are several areas where aerodynamic losses creep in to a tandem wing design. the rear wing is always in the downwash of the front wing. this reduces the efficiency of the rear wing. The 2 wings, even if identical, don't see the same wing loading and thus do not have the same angle of incidence. One of them will always be at a less efficient AOA. You also double the number of wing tips and induced drag. One of the advantages to a tandem wing is that you get the advantages of a long, high AR wing with less span. Not half the span, but defiantly less. Because the span is less it is a lot more agile in role. It is also more stable in pitch. I chose the configuration because I could move the CG to the center of the fuselage for a VTOL design. I am currently working on a larger version as a single motor pusher with a 54" wingspan.
Wow - good luck.... Brill!
Thx!
Cool project, really nice work, (subscribed). Do you have any thoughts on putting the back wing lowwer than the front wing?, I have seen some stuff around it creating greater separation when AOA increases.
Thx! I have looked briefly at staggering the wings, not high and low in the back. Lowering the rear wing gets a little complicated in that the down wash from the front wing starts to interact and lowers the effective AOA. At higher AOA the effect can change. I wanted to start with something easier to model and make sure that my results matched the aerodynamics of the model. Lower wings complicate the VTOL implication as well and I wanted to keep my first composite build as simple as possible. I would like to build a few foam test planes with different wing configurations and compare them in flight
When does a kinard become a wing? And vice versa
That’s a good question. It seems there are a lot of answers. For me, if the forward wing operates like a horizontal stabilizer, as a control surface, I consider it a canard. If it generates an appreciable proportion of the lift, I consider it a tandem. I haven’t seen an official definition.
Hey , when is the Wind Tunnel part 3 coming ?
Thanks for your explanation
I hope it helps.
@@DefiantWings a lot i am working on the same project
@@flyoran great! Good luck!
I always thought each wing is not on the same centerline
very cool!
If nothing else the test flights should be interesting 🤣
tandem wing biplane next... super vtol
I still need to get this one figured out 🤣
@@DefiantWings when can i buy them.. we ll fund yall
Too fast. Sweep the wing for speed
Great invention & blog diary 📔.
Try omnidirectional thrusters.
Btw planes land & don’t usually crash. That’s why planes don’t crash too well.
Good luck 🍀 & take care