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RE: Redesign/build FEJ
question
Has anyone checked the balance of the flight surfaces. all the strength in the world won't save your bird if flutter gets going. |
RE: Redesign/build FEJ
Static or dynamic?
I have checked mine on static, the same as Skymaster and any other. |
RE: Redesign/build FEJ
I'm sure most of the guys reading this have heard of David Galdwin. He gave me some advice on balancing F-15/F-16 stabs. He told me that they should be balanced to about 85% full balance. If they are balanced to stay at neutral when the linkage is disconnected, the servo has a hard time of finding center. The leading edge and trailing edge of the stab will move up and down while the servo hunts for neutral. I thought I would throw this out there for those that want to balance the flying stabs on their F-15 or F-16 and the F-14 and F-18. Good luck.....
Larry |
RE: Redesign/build FEJ
This is what I do, I think this is the best method in my opinion. Learned this years ago when hitecs had centering problems.
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RE: Redesign/build FEJ
ORIGINAL: Ali I have around 20 flights Dantley, and I would not call them gentle. Sure they are not fast but I have been pulling it hard. I think the pull 45 half roll and then full up half reverse to exit positive AOA high alpha is far from gentle. Especially for a big old bird like the 16. However.. and here is the however... I am not 100% in love with the direct control system. It works, and has been working.. I just feel that there is potential for movement ( In the servo arm and then in the servo mount itself ) Regards Al i look foward to your mod. i cut out these pattern and was thinking of gluing to make the rear end stronger. i will upload pics in a few. |
RE: Redesign/build FEJ
ORIGINAL: Area51.5 This is what I do, I think this is the best method in my opinion. Learned this years ago when hitecs had centering problems. |
RE: Redesign/build FEJ
ORIGINAL: Instructor I'm sure most of the guys reading this have heard of David Galdwin Larry |
RE: Redesign/build FEJ
ORIGINAL: YellowAircraft ORIGINAL: Falcon 64 The difference is the balance.. Thanks, I know I will. Yeah! God knows that's the ONLY difference! I don't suppose you happened to read Oli's thread? Well, nevermind, I just remembered that it wouldn't matter if the Good Lord himself came down and told you that it wouldn't have made a lick of difference... |
RE: Redesign/build FEJ
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F-14 swing wing design. I don't have the demotions with me right now but will post tomorrow. Here are pics
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RE: Redesign/build FEJ
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The geometry is identical on each side so they have the same rotation. the shaft in each wing is the same distance from the wing pivot.
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RE: Redesign/build FEJ
Jim, your swing wing mechanism is robust and 1000 better than the stock mechanism! You should sell a retro kit for FEJ F-14s. :)
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RE: Redesign/build FEJ
ORIGINAL: EDFJim Blast from the past tam F-16 1/8 :( :) A great flying model http://youtu.be/jE8KFdyyFxw Radio not so great that day .. |
RE: Redesign/build FEJ
ORIGINAL: dubd Jim, your swing wing mechanism is robust and 1000 better than the stock mechanism! You should sell a retro kit for FEJ F-14s. :) |
RE: Redesign/build FEJ
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Main thingvwith the geometry is that All the green arcs are the same distance and are in line with each other along the yellow line. The servo is from servocity.com mine had a 15:1 ratio they are only selling 5:1 but you could talk to them to make anything you want.
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RE: Redesign/build FEJ
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As calculated by me and others online the pivot point for the F-14 1/7 is at 25% MAC and to get 22.5 or 20% I can build a new stab would be fun to do but I have no time left before Kentucky jets or ... Just add some area with balsa and light glass skin to the back edge.
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RE: Redesign/build FEJ
ORIGINAL: EDFJim As calculated by me and others online the pivot point for the F-14 1/7 is at 25% MAC and to get 22.5 or 20% I can build a new stab would be fun to do but I have no time left before Kentucky jets or ... Just add some area with balsa and light glass skin to the back edge. You do the elevator set like my rudder set from my 1/8 scale. That set up doesn't matter much with the pivot point. |
RE: Redesign/build FEJ
ORIGINAL: dubd I've had hundreds of flights on Tam pipes without a single issue. Once I had a Tam pipe in my F-4 that showed some discoloration at the Y section. I brought the pipe to Tam just for piece of mind. Tam could have easily told me some BS for me to buy another one, but he said it was still strong and gave me some advice on what to look for in the future. A Tam pipe should be a requirement for a FEJ plane since they have a long history of failed pipes. You may be able to get away with stock factory pipes from other manufacturers, but your mileage will vary. |
RE: Redesign/build FEJ
EDFJIM
You have done exactly what I was about to do for my scratch build f-14. The exception being the servo I want to use Hitec 7980 with 600 oz at six volts. I am pleased to see I was heading in the right direction. Thanks...........Donny |
RE: Redesign/build FEJ
ORIGINAL: EDFJim As calculated by me and others online the pivot point for the F-14 1/7 is at 25% MAC and to get 22.5 or 20% I can build a new stab would be fun to do but I have no time left before Kentucky jets or ... Just add some area with balsa and light glass skin to the back edge. Jim, If you provide me some dimensions of your stab, we can see if the ones from mine couple be retrofitted to fit.. |
RE: Redesign/build FEJ
ORIGINAL: invertmast ORIGINAL: EDFJim As calculated by me and others online the pivot point for the F-14 1/7 is at 25% MAC and to get 22.5 or 20% I can build a new stab would be fun to do but I have no time left before Kentucky jets or ... Just add some area with balsa and light glass skin to the back edge. Jim, If you provide me some dimensions of your stab, we can see if the ones from mine couple be retrofitted to fit.. |
RE: Redesign/build FEJ
No disrespect to the OP but this thread reminds me of the Jet Joe threads.
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RE: Redesign/build FEJ
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Visited security at work whith some elevators, and here are some pictures from the screen.
Those two are Skymaster 1:6 scale F-16 and FEJ 1:4,6 scale F-16. Note the shaft, cross-pins and led for balance. FEJ is the one with two cross-pins inside. FEJ elevator here: |
RE: Redesign/build FEJ
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Skymaster 1:6 F-16 elevator, balanced.
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RE: Redesign/build FEJ
Hey Jim,
Did you have issues with your swing mechanism? Is the reason you changing it is to cut the weight down because you are changing it to electric? Just wanted to check because i never had issues with the wing. |
RE: Redesign/build FEJ
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Weight savings and complex design of the FEJ system and that there jack screw goes right through the wing box. Trying to have new wings made for me but over 7 months still waiting for them, I should have made my own.
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