F-35 Project in planning

[Aerobatics Man]

hello. I am new to VTOL and I have a question that I hope you may be able to answer for me. I am in the planning stages of a possible project that i hope to build. Just so there is no confusion, I have close to 50 projects that have been planned, but never done. I hope to do this one however. I want to build a F-35B. This is the Marine version of the new JSF fighter. I want to make it fully operational, complete with a turbine engine, and electric fans for vertical lift. Is there a radio that I could program myself, or some sort of device I could use to get everything properly prgamed to do this? It will use three electric fans. One behind the cockpit, like the lift fan, and then add two more on the wings for side stabilization and manuevering. I need to be able to turn off the fans when in forward flight, and then adjust throttle on each one for attitude adjustments for hovering and vertical landing. Can it be done? If not, tell me now and I will figure out something else. If it can be done, tell me what I need.

Thank you for any help.

ABman

[v22chap]

ABman
That is a fine project and a very hard one ..but I think it can be done. When I get home I can post some pix of a guy that did about what you are going to do ...it was non scale but it was a jet VTOL. Another guy is doing an all electric version ,,well has been for quite some time and I haven't seen much lately on it.

I think the high priced Futaba 14 Z could do the programing for you ,,,or Joe Orlando from Tech Models is working on a mixing board for Rudy and my V-22 projects that will probably work for you and it will not cost what the radio does.He is trying to make it programable enough to work on all VTOL projects.

Good luck on your project and keep us posted on it progress.
Larry

[rdresch]

I could get into a project like that! Very ambitious, it won"t be easy. One thought. With the main lift fan in center and smaller ones in wing tips you have roll controll and height or altitude. What about pitch controll? Please keep us updated on your progress.
Rudy

[Aerobatics Man]

Right now, it's in the planning stages, and I have no idea if I would even have the money to do this at all. Money doesn't come very easily when you're 15. I would definately like to do this project. I have been fascinated with this plane for a couple of years, so it would be nice to get a bird just like her in the air, but there is no garentee. If I do end up doing this, which I most certainly do hope so, I will keep y'all up to date, but right now, planning is all I can do.

And to answer the question on pitch control, I had come up with this idea. I want to make it a true scale ship, even in the sense that jet engine thrust would be directed downward for rear thrust. I have no idea how a turbine engine works, so a bit of researchwill have to be done, but I hope to be able to program it all into the radio so that I get more engine thrust and less fan thrust to pitch forward, the opposite on aft pitching. That was one of my biggest challenges when it came to the programing aspect. I have to get all four powerplants to act fluently, get the right thrust changes, increase power at the same time for climbing, and the fans need to shut off for forward flight. Those were my biggest concerns. Then, I'm looking at a lot of moving parts and an awful lot of weight. Retracts, possibly close to 15 servos, all the electronics, and a turbine engine are all going to add up to a heavy bird, at least by my predictions. I would also be designing this jet from the ground up, from plans, to design, to build, to where everything goes. This would be a true X plane. I do hope I can do it. It sounds like so mcuh fun already.

Thanks for the help.

[v22chap]

At the age of 15 ,,yes I would say it will be awhile , money ,time , GIRLS ,but it still don't hurt to start some basic testing with the control fans ,etc. When I started the V-22 ,,it was my 13 yr old son that had the basic idea and we worked together .After HS he decided to go to college to become what ??? you got it an aeronautical engineer ,,I wonder why ???
Go for it and keep us posted as to what you find... P.S. you can use some of your test beds for jr./ senior projects in HS maybe

Best of luck and don't be afraid to ask questions.... there is a wealth of knowledge on this board.
Larry

[Aerobatics Man]

There is one more problem I have found, and that is that since it is an X plane, and the real thing is not even on active duty, I have no way to get measurements and pics of it that I need. I have the basics planed out, and I need to figure out my Turbocad program to get this fully mapped out. I also have to do some calculations on thrust to weight ratios to determin if it would even be possible to get the right power to achieve such a feat as hovering, let alone landing and taking off. I predict there will not be a lot of power to play around with, so high throttle will be used most of the time, plus I need to find fans that match the turbines power settings, well, as close as I can get them. I think a lot of carbon fiber and fiber glass parts will be used. Then, there's the problem with getting the engine thrust to point downward, but I think that can be done with a retract arm, without the wheel.

Moving parts are another problem I may face, like how to get them to move. I want this to be scale, so everything has to move just like the real thing, which is complex enough on the fullscale bird, then you shrink it down to maybe 1/3 scale and use RC equipment. I have a lot of planning and testing to do. Wish me luck.

[v22chap]

Have you seen Doc Watson's electric one .. He has been working on an all electric one that will shed some light on what you are doing. When I get home I will try to post a link to his website for you .He also has some nice pictures of it and a vid of all the doors opening up for hover mode. I fly the plane on Battle field 2 and it is a lot of fun, but I am sure no where near what the real one ,,,let alone a model one will do.It is like GP's V-22 ,,it is no where near how my model flys let alone how the real one flew when I got the chance to fly the Governments simulator for it. :D
Some times figures lie too ...so just do it sometimes is the best way to find out for sure.

[v22chap]

Here is the url to Doc's page Doc Watson's X -35 B Vtol (http://www.awatson1.fsnet.co.uk/)
Larry

[Aerobatics Man]

Much ablidged. That is a good project and looks like it is turning out very well. i'll have to keep an eye on that. And, hopefully in a few years, I'll be flying the real F-35A. The dream is to become a USAF pilot.

[v22chap]

Man that would be a dream come true..... keep the faith man -- and plan ahead :D :D :D
Larry

[Aerobatics Man]

I'm currently doing some physical training in preparation. I was told by a friend that is a pilot trainee that being able to do all these exercises can be the determining factor on if I get in. He said that there have been many occassions when a slot was lost because of one push up. I want to prevent that from happening and increase my chances of success, so I am training now. The dream will come true, if I have anything to say about it.

[v22chap]

That same thing happened to my son when trying to get an airforce academy slot.Plus the bad eye sight he had going on.You need to plan ahead like you are and start getting stuff lined up that has to be done ...start searching the library on how to if you plan to do the academy route...cause its a long tedious haul to get there from here.
Good luck

Larry

[Aerobatics Man]

Well, for starters, to get into the acadamy, I have to get my grades up, and that is impossible for me to do in spanish, for it is my worst subject, but yet I do okay in it. I just have to keep working and get as much done as I can get done. But, we are getting off the subject of this thread, so I will stop talking about the Air Force and how awsome it will be to make it in.

[secretspy711]

I realize the last post here was in February, but I thought I'd just put my two cents in.

A little background: I graduated from college a little over a year ago, and right now I'm a design engineer for Lockheed Martin working on JSF. It's a cool job, I enjoy what I do. Being so close to something so global and new is downright awesome.

Sounds like you've got quite a project here. It would be awesome if it could be fully functional, especially with a mini-turbine in it. Do you know those can run $3k and up? I'm planning a profile foamie electric version...which I estimate will run a couple hundred dollars (which is mostly all the servos/motors, etc) minus the radio, which I already have a JRXP8103, which I think will do the trick. Foam is cheap. I also plan to use props instead of ducted fans because the ducts are just added weight in something like this.

Are you going to have yaw control? That's the one thing I think I might have to live without in building this. It's another servo and more mechanisms, unless I could figure out how to do it by changing the speed of the props proportionally to let the torque do it, and keep the same overall thrust. Speaking of that area, are you really going to try to make a scale version of the 3-bearing-swivel nozzle like on the real thing? Props to you, if you are. That would be cool. It will have to be a lot beefier (not to mention metal) than the electric one at the link that was posted.

[uriah]

3-bearing-swivel nozzle... :censored: ... That is un-direct thrust vectoring if I am not mistaken...

I was told a model sized turbine wouldn wear down and/or seize up if it had to push the exhaust around a 90 degree corner. In this case the whole engine would have to rotate on a model sized craft.

But from what I read above that is not what this guy has in mind. He is using three powerplants, one lift fan, and one in each wing. The F-35 only has two powerplants and ducts which extend to the wing tips for roll and yaw. (correct me if I am wrong...)

secretspy711, I think you would be interested or at least enjoy reading my thread.

http://www.rcgroups.com/forums/showthread.php?t=550218

I am working on thrust vectoring for now, but in the future I want to design my own V/STOL aircraft.

Three cents if you please... ;)

Regards,
Uriah N. G.

[MeGrimm]

.... Money doesn't come very easily when you're 15 ....

It doesn't come any easier when you're 25 - at least in my case! :(

I can't really help you much with this awesome project, but it's great to see your ambition. Do keep us posted!

Martin

[Medic33]

I was told a model sized turbine wouldn wear down and/or seize up if it had to push the exhaust around a 90 degree corner.

Sorry, gotta throw my 2 cents in here. A model turbine will not do that - if the exhaust is designed properly. Turbine engines, like gas recip engines are basically just great big (or small!) air pumps. Air goes in, air goes out.

The problem is backpressure - too much of it (too sharp a bend, too small diameter pipe, etc) and the air can't go out. In the case of a turbine, it most likely wouldn't even start - or worse, you would end up with a hot start. Goodbye money, certainly goodbye engine, possibly goodbye model.

It can be done - for starters, you must ensure that the pipe is constantly increasing it's cross section just behind the engine - I know, that will decrease the pressure (which was the point...) and the thrust. Go read up on divergent / convergent nozzle theory. It is possible.

[uriah]

I've been told nothing in the 15-20lb range will NOT work efficiantly. 25 and up can be made to work.

I love the concept of thrust vectoring, and am working on designing a plane which uses purley such to manouver.

There are problems, and benifits. Like a a JetSki which uses a form of vectoring to manouver. Thus if you go out of control and cut the throttle you have no control.

WWW.SECRETS2FLIGHT.DFUZED.ORG

now handing the thread back to starter.

-UNG

[Eddy]

"I was told a model sized turbine wouldn wear down and/or seize up if it had to push the exhaust around a 90 degree corner. In this case the whole engine would have to rotate on a model sized craft."

Uriah, who told you this? That is not true at all. it would work fine for a model sized turbine.

[uriah]

I was told by a friend in the Aerospace industry...

[csr432]

Sorry about the long post in advance - hope this helps.

In your post you discuss using fans (I assume you are embedding them flush in the wings) and such in order to get what a heli pilot would call cyclical control over the Aircraft (pitch/Roll/Yaw in hover).

Your solution may be to solve the problem more like the real Aircraft. Full Scale X-35B and AV-8B both use bleed air from the compressor stage that is piped out to the ends of the wings and tail. By opening valves the bleed air jets out (for example at the wingtip there are jets pointing up and down in order to give roll control authority at zero velocity where aerodynamic controls would be inneffective).

You may want to contact some engine manufacturers (ie: Jetcat) and determine what options may exist for a custom engine or determine if bleed air can be extracted from the compressor stage of their engines.

One more option to look at is driving the fan from shaft power on the engine (like X-35b) using the heli-cat engine (basically a turboprop) or I think some of the jet engine makers even have actual turboprop designs available.

Again, I think the biggest part of the project is finding one or more suitable power plants and in this case, I think bigger solves a lot of problems but of course also drives up costs. If you are serios about it, I would contact the jet engine manufacturers to see their thoughts on bleed air extraction, vectoring exhaust thrust, and using some of the shaft power to drive the fan since a single engine solution should reduce complexity and save weight (a really important factor for hover capability). To effectively hover a model you really need to be at around a 1.5 to 1 thrust to weight ratio with static thrust of your hover powerplant. In comparison, a model helicopter can typically carry a load equal to its own weight and still have useful control authority (although it would be demanding to control) meaning that it would be operating at better than a 2 to 1 ratio by comparison.

I would also consider the use of rate gyros (or whater they call them now) on all 3 axis to help with hover. As unstable as a heli is, they do have a few inherent stability items such as hiller bars and the gyro effect of the large blades in rotation - you will have none of that in pure jet thrust hover so it will be HIGHLY UNSTABLE. To this end, I would actually build a hover rig to test the power plant and controls and to learn to fly it - then move on to building the actual model around the hover rig in order to work incrementally.

[Brandano]

Actually, I wonder if a helicopter jet turbine could be adapted to be a high bypass turbofan. Apart from the use in VTOL models, the increased thrust and lower "outer" temperature of such a configuration could be useful for smaller full-scale planes too.

[wdicken]

I tried an experiment on an old airplane. I used a compressed air flow from a gas cartridge as a balancing "jet". So when the wing dipped, the jet blasted and the wing leveled out. Looked good in theory, worked badly in practice (hard to regulate) so I tried creating a piston pump (like my old aquarium air pump). It ran all the time and the servo actually only diverted the flow (in the middle, both sides got equal thrust) but it allowed me to run a very small tube through the wing.

It worked, but I ended up approaching the design differently. But I wonder if it wouldn't help solve some wing tip stabilizer issues.

Thanks

[helidude2]

hi i like your idea i actualy was thinking of building one too i thought of a herrier first but an f-35 would be so much better i began designing it a couple days ago unfortunaly i do not have any fancy softwere to help me design it all i have is a coppyer and a pensil but so far it is turning out preaty weel i am building a cardboard version first to figure out any kinks but then im going to use a computer to recreate my parts for the basa wood ill put some pictures up when i get clocer to the finished frame. by the way thye caliper is on 6 inches

[tungym]

Hey, I got the body and want to convert it to VTOL. With my previous experience in V22-like VTOL , this F35-VTOLis even more challenging!

http://drtungym.blogspot.com/2008/08/f35-vtol.html

I am reluctant to use tri-copter like ducted fan.

Compressed air seems a good theoretical material, but seems no reliable linear control mechanism.

In my mind, 3 point thrust is necessary.