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PRANDTL-D Foam Board Wing by FoamyDM

What plane should I add the Prandtl-D Wing to?

  • Mini-Arrow

    Votes: 20 38.5%
  • FT-Explorer

    Votes: 15 28.8%
  • FoamyDM-HS Carrier

    Votes: 6 11.5%
  • FT-Simple Cub

    Votes: 6 11.5%
  • FT-Tiny Trainer

    Votes: 12 23.1%
  • FT-Bloody Baron (somehow)

    Votes: 7 13.5%
  • Airliner

    Votes: 14 26.9%

  • Total voters
    52

Scotto

Elite member
#86
Awesome! Congrats on your success! I voted for airliner but I picture a tailless airliner. Or a Storch with no rudder:unsure:. I might have to try it myself. Great work Thanks for sharing! Nice video too I was thankful you had a hat cam this time even if I still couldnt see the plane half the time:D
Edit Scratch the Storch now Im thinking canard airliner like beech starship
 
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FoamyDM

Building Fool-Flying Noob
#87
Awesome! Congrats on your success! I voted for airliner but I picture a tailless airliner. Or a Storch with no rudder:unsure:. I might have to try it myself. Great work Thanks for sharing! Nice video too I was thankful you had a hat cam this time even if I still couldnt see the plane half the time:D
Tailless Planes - That is exactly it! I have a DC3 plan set here somewhere.

If it helps, it is a little easier to follow IRL, although, at times... it completely disappears... I think it will work better higher up really. the viewing angle will keep it more perpendicular. Thank you for the feedback on the video @Scotto I never know how they are being received.

QUESTION
Would you rather I put together a FT style creased version, or the current build with paper removed and a smooth airfoil?


Phase 3 Musings.
Then I move on to Phase 3! After the Arrow, I see that an Airliner or Storch are the next in line at 29%. I know I will tackle both the Arrow and the next...
Question is... What is the point of Phase 3... To test if the wing still behaves when it has a fuse or is it to test the efficiency increase (longer flights)?
 

Scotto

Elite member
#88
Would you rather I put together a FT style creased version, or the current build with paper removed and a smooth airfoil
I think it looks awesome right now. I think the biggest help for me making it would be some kind of jig. If you had top half and bottom half "negatives" of the airfoil with tabs on the bottom that fit into holes in a piece of fb that are spaced every so many inches, it might be more work up front but if you could rearrange (mirror) them for the other side, it could have a better chance of making it symmetrical and getting the correct angles. Something Ive been doing is using spray glue and replacing the peeled paper to "lock in" the new curve. It gives it all (maybe more) of its strength back. Ive found it helps to have a "negative" or form to push it into.
Then I move on to Phase 3! After the Arrow, I see that an Airliner or Storch are the next in line at 29%.
I just said Storch cause the wingspan is about the same and maybe you could just strap it on without too much effort just to see what happens. Explorer is the same way I guess but I didnt know that until now. Really just because you shouldnt need the rudder in theory doesnt mean you have to remove it. It might still be nice to have.
What is the point of Phase 3..
That sounds like a good question for part 3 of the interview with Red Jenson on the RC Noob Podcast!
 
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FoamyDM

Building Fool-Flying Noob
#89
This Saturday I took this back out with the Prandlt-D Modified Wing to test the spar reinforcements, and to fly with it. Along with the FoamBoard Reptile Dragon II @BATTLEAXE put together. As with my luck... As storm was rolling past a mile out. and the winds just started kicking up, 10 knots gusting to 23 at least. Perfect time for a flight right? (most would have sense, and stay grounded.)

I decided it was time to see how they performed in the wind.
Field Flight.jpg

After trying to launch with a different (heavier) battery without success earlier in the week, I just put on what worked at the marks I had. It launched just fine, and I began flying. I caught a few thermals, but I noticed the pockets of rising air were aggressive, and the gusting would take the wing tips and try to bat the plane around. The roll is slow and the coupled Yaw is on pace. This made battling the frequent violent upsets slow and a bit scary. Some times, it was better to head inverted and loop out like an Immelmann. There were many buffets that looked like the end of the Video from last week, a quick positive then negative. But this time the wing stayed together. It was the violent motion that finally loosed a battery and caused it to become tailheavy and come down (guided). She will Fly again.

Later I calculated out exactly where to place the LARGE 5Ah 3S battery for the Prandlt wing. I am working on putting a pod to hold the battery and give a better platform to balance the battery without needing ballast as well as a place for FPV. updates on that soon. I would love to have that ready for FliteFest
 
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FoamyDM

Building Fool-Flying Noob
#90
Something Ive been doing is using spray glue and replacing the peeled paper to "lock in" the new curve. It gives it all (maybe more) of its strength back. Ive found it helps to have a "negative" or form to push it into.

I just said Storch cause the wingspan is about the same and maybe you could just strap it on without too much effort just to see what happens. Explorer is the same way I guess but I didnt know that until now. Really just because you shouldnt need the rudder in theory doesnt mean you have to remove it. It might still be nice to have.
I have been toying around with the Replace-the-Paper-using-Spray-glue for some time, (just keep forgetting it, when I comes time). I never thought about the negative form being a big help.

I think in will build a Explorer pod. it will have tricycle gear, and a tear drop back end with a rudder for turn assistance. (like it starts functioning after 25% stick movement)
 
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FoamyDM

Building Fool-Flying Noob
#91
OK... I'm going to strike that, last statement on adding a rudder. I will add internal Ailerons that function to aid in roll after 25% aileron stick movement.
 

FoamyDM

Building Fool-Flying Noob
#97
I had a little bit of time today, and I realized I could make an Arrow size/shape Prandtl wing, as per Popular Request. This design scales down and nicely fits to one sheet and is 36.5" wingspan, could be a ~250g flyer if you wish it to be. (with diligent weight management & and system management).

This goes together almost identically, the difference is the 23° sweep of the wing, and the wing end treatment. construction is the same.
big thing is the twist in each wing needs to be symmetrical. this flies off the same system, but should fly much faster.
2204, 2300kv motor
30a-40a ESC 3-6s
1300mAh 3s - 850mAh 6S
2 9g servos (5g will work too)
you may need 2x Servo extensions
I would put a tongue depressor on the bottom, and line the tip with the nose, to protect from harder landings.
1636493519960.png

Until I build and prove this out it is "build at your own risk". Please do. if you do, let me know your experiences.

@Baron VonHelton - There has been no falling out with NASA to my knowledge. Youtube is more likely to be the trouble...
 

LitterBug

Troll Spammer
#98
I had a little bit of time today, and I realized I could make an Arrow size/shape Prandtl wing, as per Popular Request. This design scales down and nicely fits to one sheet and is 36.5" wingspan, could be a ~250g flyer if you wish it to be. (with diligent weight management & and system management).

This goes together almost identically, the difference is the 23° sweep of the wing, and the wing end treatment. construction is the same.
big thing is the twist in each wing needs to be symmetrical. this flies off the same system, but should fly much faster.
2204, 2300kv motor
30a-40a ESC 3-6s
1300mAh 3s - 850mAh 6S
2 9g servos (5g will work too)
you may need 2x Servo extensions
I would put a tongue depressor on the bottom, and line the tip with the nose, to protect from harder landings.
View attachment 211447
Until I build and prove this out it is "build at your own risk". Please do. if you do, let me know your experiences.

@Baron VonHelton - There has been no falling out with NASA to my knowledge. Youtube is more likely to be the trouble...
I have added this to my winter build list!!!

THANK YOU!!!!!

LB
 

L Edge

Elite member
I had a little bit of time today, and I realized I could make an Arrow size/shape Prandtl wing, as per Popular Request. This design scales down and nicely fits to one sheet and is 36.5" wingspan, could be a ~250g flyer if you wish it to be. (with diligent weight management & and system management).

This goes together almost identically, the difference is the 23° sweep of the wing, and the wing end treatment. construction is the same.
big thing is the twist in each wing needs to be symmetrical. this flies off the same system, but should fly much faster.
2204, 2300kv motor
30a-40a ESC 3-6s
1300mAh 3s - 850mAh 6S
2 9g servos (5g will work too)
you may need 2x Servo extensions
I would put a tongue depressor on the bottom, and line the tip with the nose, to protect from harder landings.
View attachment 211447
Until I build and prove this out it is "build at your own risk". Please do. if you do, let me know your experiences.

@Baron VonHelton - There has been no falling out with NASA to my knowledge. Youtube is more likely to be the trouble...
Do you have a build thread and information on how you determined twist angle and how you accomplished it for the above model?