Fly Eagle Jet F-14 Crash (video)
06-18-2013, 04:36 PM
#2001
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RE: Fly Eagle Jet F-14 Crash (video)
We are at toys in that scale, comprehend witht it.
That was my point..but important to all of them/us..
As I said, ready to defend the balance at any time.
That was my point..but important to all of them/us..
As I said, ready to defend the balance at any time.
06-18-2013, 04:51 PM
#2002
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RE: Fly Eagle Jet F-14 Crash (video)
If it wasnt possible, full scale aircraft manufacturers wouldnt describe in detail the exact procedure and specifications for balancing their flight controls
I stick to airfield and basic knowledge facts, those who also stick & put your wallet were it should be.
06-18-2013, 05:38 PM
#2003
RE: Fly Eagle Jet F-14 Crash (video)
ORIGINAL: Falcon 64
No, you can`t.
ORIGINAL: rhklenke
Yes, one reason may be that in Rudi's case, he removed the other factor in flutter that Falcon conveniently ignores, the spring constant of the control linkage.
You can take a surface that does not flutter on its own because of static and dynamic balancing, and cause it to flutter by introducing ''springiness'' in the control linkage.
Bob
Yes, one reason may be that in Rudi's case, he removed the other factor in flutter that Falcon conveniently ignores, the spring constant of the control linkage.
You can take a surface that does not flutter on its own because of static and dynamic balancing, and cause it to flutter by introducing ''springiness'' in the control linkage.
Bob
Bob
ORIGINAL: Falcon 64
Do not forget full-size fighters are lightyears apart of our game..!
They go supersonic, and are SAFE behind our knowledge and can NEVER! be compared to what we do. If you build a Tomcat in the thought of full-size, you are safe no matter how, but requires the same rigidness and hydraulics.
BUT in modelleing we can`t yet do that, and that answers your reply..and that is where you have questions. Copy a full-size, and you will crasch & burn on and in the terms of the modelling in jets we have done uptil now.
I eeek every time someone compares a full-size aircraft up to their model and think they do it 7 timer smaller, and also think they are in a good path in jets and forces in it, there are dimensions! apart.. PLEASE stop thinking we can compare aerodynamics on our models with supersonic fighters.. ( ! )
Once you do, you are mislead and on your own..and you will loose.!
Our thing happens below 600 km/h, way below subsonic. It`s from there we have to admit our laws exists, not to compare your jet against the original, nothing of it, (!!)... We are dealing model airplanes, the laws there are grewing rapidly once the size/weight and speed grows whith it.
Do not forget full-size fighters are lightyears apart of our game..!
They go supersonic, and are SAFE behind our knowledge and can NEVER! be compared to what we do. If you build a Tomcat in the thought of full-size, you are safe no matter how, but requires the same rigidness and hydraulics.
BUT in modelleing we can`t yet do that, and that answers your reply..and that is where you have questions. Copy a full-size, and you will crasch & burn on and in the terms of the modelling in jets we have done uptil now.
I eeek every time someone compares a full-size aircraft up to their model and think they do it 7 timer smaller, and also think they are in a good path in jets and forces in it, there are dimensions! apart.. PLEASE stop thinking we can compare aerodynamics on our models with supersonic fighters.. ( ! )
Once you do, you are mislead and on your own..and you will loose.!
Our thing happens below 600 km/h, way below subsonic. It`s from there we have to admit our laws exists, not to compare your jet against the original, nothing of it, (!!)... We are dealing model airplanes, the laws there are grewing rapidly once the size/weight and speed grows whith it.
I guess they should publish disclaimers for those papers - "Falcon64 said that models and full-scale don't obey the same laws of aerodynamics, therefore all of this work is actually wrong..."
Bob
06-19-2013, 05:21 AM
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RE: Fly Eagle Jet F-14 Crash (video)
A FULL AND FRANK INTERCHANGE OF VIEWS IS OK BUT KEEP IT POLITE PLEASE.
Some of the recent posts have been right on the edge of what is acceptable.
Some of the recent posts have been right on the edge of what is acceptable.
06-26-2013, 07:03 PM
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RE: Fly Eagle Jet F-14 Crash (video)
Roger Alli: Re: post 83, U tube vids. Very well done! I'l never ride in an airplane again! Joking, but great real time, 1/1 airplane examples of flutter. Problems with the V-tail Bonanzas years back, mainly caused by loss of control in the clouds, but he V-tails often came apart in a highspeed uncontrolled spiral. They beefed it up a little later and taught private pilots how to recover from those situations. wallace.tharp
06-27-2013, 05:40 AM
#2008
RE: Fly Eagle Jet F-14 Crash (video)
ORIGINAL: FalconWings
Please! We are trying to remove life support!
ORIGINAL: YellowAircraft
Ughhhh....
Are we still at the 'static balance is a magic talisman to all ills with blown-up jets' thing??
Ughhhh....
Are we still at the 'static balance is a magic talisman to all ills with blown-up jets' thing??
LOL,
Fair enough.
06-27-2013, 12:58 PM
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RE: Fly Eagle Jet F-14 Crash (video)
ORIGINAL: jet time
Ian, no doubt that you (and always do) a very thorough and great build. That is not a question here at all. PERIOD! You did mention the pivot point and that is another thing that Dantley and I were looking at. Ken has been flying his for over a year and has had no issues. So why or what was different here? That is what we need to figure.
ORIGINAL: ianober
Here is a photo of the elevator mechanism. The servo arm was swapped for a SWB metal one so the plastic WAS NOT used. This is by far the most ridiculously overbuilt mech I have ever done. the arms are .25 solid aluminum tapped at both ends for 4-40 threaded rod which secures aluminum rod ends. I HIGHLY doubt this part failed pre-flutter. I calculated the MAC and pivot point and it would appear that it is right at about 23% which should be acceptable. Maybe some of the more experienced in aerodynamics can offer up some theories.
*** hmm pictures not working again, shocker. Dantely, how did you get your pics on? ***
Here is a photo of the elevator mechanism. The servo arm was swapped for a SWB metal one so the plastic WAS NOT used. This is by far the most ridiculously overbuilt mech I have ever done. the arms are .25 solid aluminum tapped at both ends for 4-40 threaded rod which secures aluminum rod ends. I HIGHLY doubt this part failed pre-flutter. I calculated the MAC and pivot point and it would appear that it is right at about 23% which should be acceptable. Maybe some of the more experienced in aerodynamics can offer up some theories.
*** hmm pictures not working again, shocker. Dantely, how did you get your pics on? ***
06-27-2013, 01:18 PM
#2010
RE: Fly Eagle Jet F-14 Crash (video)
ORIGINAL: jeaton01
I'm not a jet guy, but for all flying tails it is normal for the pivot point to be close to 40% MAC. 23% seems very far forward.
ORIGINAL: jet time
Ian, no doubt that you (and always do) a very thorough and great build. That is not a question here at all. PERIOD! You did mention the pivot point and that is another thing that Dantley and I were looking at. Ken has been flying his for over a year and has had no issues. So why or what was different here? That is what we need to figure.
ORIGINAL: ianober
Here is a photo of the elevator mechanism. The servo arm was swapped for a SWB metal one so the plastic WAS NOT used. This is by far the most ridiculously overbuilt mech I have ever done. the arms are .25 solid aluminum tapped at both ends for 4-40 threaded rod which secures aluminum rod ends. I HIGHLY doubt this part failed pre-flutter. I calculated the MAC and pivot point and it would appear that it is right at about 23% which should be acceptable. Maybe some of the more experienced in aerodynamics can offer up some theories.
*** hmm pictures not working again, shocker. Dantely, how did you get your pics on? ***
Here is a photo of the elevator mechanism. The servo arm was swapped for a SWB metal one so the plastic WAS NOT used. This is by far the most ridiculously overbuilt mech I have ever done. the arms are .25 solid aluminum tapped at both ends for 4-40 threaded rod which secures aluminum rod ends. I HIGHLY doubt this part failed pre-flutter. I calculated the MAC and pivot point and it would appear that it is right at about 23% which should be acceptable. Maybe some of the more experienced in aerodynamics can offer up some theories.
*** hmm pictures not working again, shocker. Dantely, how did you get your pics on? ***
Really!? please enlighten us with physical proof of that!
[8D]
07-12-2013, 07:51 AM
#2013
RE: Fly Eagle Jet F-14 Crash (video)
I have not been on RCU in probably 4 years. I jumped on to see what is going on. It took me the last four days on and off to read this thread.
The prototype megabar fuse was completely made from honeycomb sandwiched in 1 ounce glass on each side. It was incredibly strong and light, weighed 1 lb. In contrast subsequent fuse's were made from two layers of four ounce and a layer of 1 ounce and weighed just shy of five pounds. The prototype was flown fast and hard for about 150 flights and won a couple of awards before a flameout ended with the jet flying through a barb wire fence. Confetti Eddie would have been proud of the pieces that came out the other side. Subsequent airframes were flown hundreds of times, maybe more. One of mine is hanger queening somewhere in a friends garage.
There were two primary bulkheads made from 1/4" five ply. They were hysol'd to the fuse and the jet used an aluminum spar system whereby the landing gear was tied directly to the spar system in the wing so all landings were distributed to the spar system across the airframe.
Eddie Weeks did the original design and said it would handle around 40 g's. This was before Eagle Tree and the likes could tell you your G loads, but I was certain that the airframes could not keep up speed enough in turns to go over 10 g's. I don't know what the current standards of analysis is, but you could easily put a 3g landing on the gear I designed and built and maybe you would break a flex plate.
I have built multiple airplanes with flying stabs, and I agree with Matt and Tam regarding their comments about placement of the rotation point and Shaun's comments about balancing the stabs are accurate. When I was involved in this stuff, the most common way to do this was dremel a hole in the rib at the inside edge of the flying stab, and load epoxy and bb's into it, and then dremel out the lead till it was properly balanced. Someone sold a balancing kit that would hold the part while you were balancing it.
The construction of the stab in the F-14 was improper, no doubt, but I can't explain what I see with torsion in the rear of the fuse in the slow mo video. My vast experiance with all sorts of composite materials tells me that the honeycomb in the fuse failed loosening the bulkhead and then the aerodynamic loads on whatever was left in there caused what is seen in the video, but I don't really know for sure.
Having manufactured multiple air frames, retracts, wheels and brakes, I can say that all comments related to BVM and some of these other great manufacturers are more than accurate. In fact, it was owning a couple of BVM models that drove me to try to achieve that level of quality in my work. To me their products were a standard of excellence.
My brother was in a boating accident in 2005 and did not have insurance and had a golf ball sized portion of his brain removed. It cost my family more than 2 million dollars to put him back together and in the process we lost all our toys, homes, etc, it took a few years for it all to catch up with us. I can't properly relay the emotion of having a brain surgeon tell you that you have to come up with $500,000 prior to a life saving operation. I live a very meager life now compared to what I was once able to accomplish. In the process of closing everything down I know I upset a couple of people in the hobby. For that I apologize. If any of you are reading this, hope to make it up to you some day. I will check in here from time to time. Some of the greatest minds I ever met are involved in this segment of the hobby.
Someday I would like to have the opportunity to take a close look at the products FEJ is producing, my history on RCU, building etc, would suggest I could come up with some clever ways to increase the strength of their system to make a very good flying model.
All the best to Jet Flyers on RCUniverse and on behalf of those who create, I apologize to you for the loss of your model Dub.
Sean
The prototype megabar fuse was completely made from honeycomb sandwiched in 1 ounce glass on each side. It was incredibly strong and light, weighed 1 lb. In contrast subsequent fuse's were made from two layers of four ounce and a layer of 1 ounce and weighed just shy of five pounds. The prototype was flown fast and hard for about 150 flights and won a couple of awards before a flameout ended with the jet flying through a barb wire fence. Confetti Eddie would have been proud of the pieces that came out the other side. Subsequent airframes were flown hundreds of times, maybe more. One of mine is hanger queening somewhere in a friends garage.
There were two primary bulkheads made from 1/4" five ply. They were hysol'd to the fuse and the jet used an aluminum spar system whereby the landing gear was tied directly to the spar system in the wing so all landings were distributed to the spar system across the airframe.
Eddie Weeks did the original design and said it would handle around 40 g's. This was before Eagle Tree and the likes could tell you your G loads, but I was certain that the airframes could not keep up speed enough in turns to go over 10 g's. I don't know what the current standards of analysis is, but you could easily put a 3g landing on the gear I designed and built and maybe you would break a flex plate.
I have built multiple airplanes with flying stabs, and I agree with Matt and Tam regarding their comments about placement of the rotation point and Shaun's comments about balancing the stabs are accurate. When I was involved in this stuff, the most common way to do this was dremel a hole in the rib at the inside edge of the flying stab, and load epoxy and bb's into it, and then dremel out the lead till it was properly balanced. Someone sold a balancing kit that would hold the part while you were balancing it.
The construction of the stab in the F-14 was improper, no doubt, but I can't explain what I see with torsion in the rear of the fuse in the slow mo video. My vast experiance with all sorts of composite materials tells me that the honeycomb in the fuse failed loosening the bulkhead and then the aerodynamic loads on whatever was left in there caused what is seen in the video, but I don't really know for sure.
Having manufactured multiple air frames, retracts, wheels and brakes, I can say that all comments related to BVM and some of these other great manufacturers are more than accurate. In fact, it was owning a couple of BVM models that drove me to try to achieve that level of quality in my work. To me their products were a standard of excellence.
My brother was in a boating accident in 2005 and did not have insurance and had a golf ball sized portion of his brain removed. It cost my family more than 2 million dollars to put him back together and in the process we lost all our toys, homes, etc, it took a few years for it all to catch up with us. I can't properly relay the emotion of having a brain surgeon tell you that you have to come up with $500,000 prior to a life saving operation. I live a very meager life now compared to what I was once able to accomplish. In the process of closing everything down I know I upset a couple of people in the hobby. For that I apologize. If any of you are reading this, hope to make it up to you some day. I will check in here from time to time. Some of the greatest minds I ever met are involved in this segment of the hobby.
Someday I would like to have the opportunity to take a close look at the products FEJ is producing, my history on RCU, building etc, would suggest I could come up with some clever ways to increase the strength of their system to make a very good flying model.
All the best to Jet Flyers on RCUniverse and on behalf of those who create, I apologize to you for the loss of your model Dub.
Sean
07-12-2013, 08:01 AM
#2014
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RE: Fly Eagle Jet F-14 Crash (video)
Great to hear from you and hope your brother is doing well.
Also hope you be able to pull a Isobar from the molds for your personal use soon! As based on current affairs, seems to self design and build our own stuff keeps as relevant as the old days.
Best regards, Enrique
Also hope you be able to pull a Isobar from the molds for your personal use soon! As based on current affairs, seems to self design and build our own stuff keeps as relevant as the old days.
Best regards, Enrique
07-12-2013, 08:12 AM
#2015
Thread Starter
RE: Fly Eagle Jet F-14 Crash (video)
Sean, I'm very sorry to hear about your brother and the hardship your family went through. IIt's a stark reminder in how fragile life is. I remember you being very active within the RC Jet comunity when I first started and I hope you return. Best wishes to you and your family.
01-16-2014, 05:44 AM
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Hi all,
I personally don't like this kind of setup (rods parallel)
Reasons:
- To get the the right throw on the elevator, you have to reduce throw on the servo (lets say servo 45° for elevator 20°)
- You lose resolution on the servo.
- You lose power on the elvator.
- Any slop in the servo gear will be visible 100% on the elevator.
Go to the Fly Eagle F-18 forum. The is the solution.
I simulated the position of the holes in the servo horn on a CAD program (NO stress on linage with maximal deflection) an drilled the holes on a mill with digital display.
Best regards
Flilek
I personally don't like this kind of setup (rods parallel)
Reasons:
- To get the the right throw on the elevator, you have to reduce throw on the servo (lets say servo 45° for elevator 20°)
- You lose resolution on the servo.
- You lose power on the elvator.
- Any slop in the servo gear will be visible 100% on the elevator.
Go to the Fly Eagle F-18 forum. The is the solution.
I simulated the position of the holes in the servo horn on a CAD program (NO stress on linage with maximal deflection) an drilled the holes on a mill with digital display.
Best regards
Flilek
01-17-2014, 01:12 PM
#2023
LOL,
I'm sure there's a clinical term for people who chest-beat and defend the indefensible to their last breath because they don't want to admit they've been suckered. I mean, is it a 'witch hunt' if she really is a witch? LOL....
I'm sure there's a clinical term for people who chest-beat and defend the indefensible to their last breath because they don't want to admit they've been suckered. I mean, is it a 'witch hunt' if she really is a witch? LOL....
03-12-2014, 02:07 AM
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I have tried to contact FEJ a few times to get the recommended throws for all the control surfaces and COG but no response. Is there anyone who can tell me what it should be? would appreciate any advice from anyone. I have the HC model and have modified the tail area with CF plates and balanced elevons etc. so comfortable now to fly it. Thanks. Tom.
