Forum: General F-22A Raptor forum

BELA wrote:

pants3204 wrote:

Where did you find these drawings of the bulkheads? I've been trying to make a larger scale F-22 with balsa but I couldn't find any decent cutaway resources.

You start with a 3d model, then use a cad program to extract cross sections from it. If you cant model one, there are some decent ones available from 3rd party companies, though the good ones are very pricey. turbosquid might be a good place to start.

Thank you. I also noticed on your site that you modeled the complete cockpit in CAD, to very fine detail. Did you just guesstimate the dimensions of components or were you able to find specifications?

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If you are working with a good cad program, you can import web available pictures and starting with known parameters, for example the size of the acesII seat or the size of the LCD screens, you can apply markers that will help you work most everything out. you can size up the cockpit and work out angles. most pictures taken recently store the exif data in the file that will give you focal info of the shot and the camera which took it. with all this info, you should be able to work things out even if the pictures were not taken orthographically.
I'm currently dong the same for the F-35 cockpit, and though I dont have complete dimensional data for the martin baker bang seat yet, I do know the size of the LCD screen, as It is posted on the internet. so that is a good start.
Go for it!

BELA wrote:

If you are working with a good cad program, you can import web available pictures and starting with known parameters, for example the size of the acesII seat or the size of the LCD screens, you can apply markers that will help you work most everything out. you can size up the cockpit and work out angles. most pictures taken recently store the exif data in the file that will give you focal info of the shot and the camera which took it. with all this info, you should be able to work things out even if the pictures were not taken orthographically.
I'm currently dong the same for the F-35 cockpit, and though I dont have complete dimensional data for the martin baker bang seat yet, I do know the size of the LCD screen, as It is posted on the internet. so that is a good start.
Go for it!

Thank you!

I am currently using SolidWorks (as that and SketchUp are really the only CAD software I use in my robotics class, and therefore the only ones I am familiar with). I'll look into that feature.

As for the realism of your F-22 model, to what extent will you be pursuing true-to-life features? From your website I see you're after photographic realism but I was curious about what you were going after as far as avionics, propulsion, and munitions are concerned? With what little electronics and micro-controller experience I have (again from my robotics class) I have figured how to make a rudimentary x-band radar utilizing Arduino (nothing electrically scanned, it's all mechanical so far. I figure jumping up to purely electrical systems would require significant investment, I will look further into this), and how to interface that with other systems. My ultimate goal (as some call it, a pipe dream Cool

) is to achieve as little deviation from the actual F-22 in my model (classified components notwithstanding of course) and arm myself with a small fleet of scale F-22's to defend my home from other RC flyers in my area Crazy Pilot

. I was also considering a scale similar to what you have chosen due to form factor constraints of the arrays, Arduino, propulsion, etc etc. And even if it isn't a flying model I would like to get the control surface movements etc all to scale as a much as possible.

Other targeting methods I have looked into include:
Passive and Active IR
I have discounted this approach because of the very limited range that is offered on the consumer level. Active IR detection is a possibility but my level of knowledge just isn't advanced enough to construct the sort of system required to detect at 50m+

Phased Array Ultrasonic detection
Same reason as above, however even less practical considering it has less range than IR.

Optical
A very possible solution that I will have to look in to.

Some sort of electromagnetic beacon
Abandoning the whole target acquisition theme altogether, this method would emit some sort of IR or electronic signal (likely 2.4ghz or blu-tooth) for the sole purpose of letting the other aircraft know its position. Kind of like those "dogfighting helicopters" you can buy at walmart.

Another interesting facet of real-to-life modeling I have researched is a full cockpit representative of the real F-22 cockpit. Fortunately Arduino has such an expansive community being that it is open source, and libraries are readily available for these kinds of things. The main challenge here would be procuring accurate joysticks, etc. Means of real time video and data transmission are already readily available in the RC FPV world, the main challenge would be interfacing the peripherals with the flight control system onboard the aircraft. I'll have to continue researching these technical and monetary (large investment to say the least for a high school student) challenges.

As for the airframe itself I was planning on taking, again, a more scale route. I have access to a large supply of raw materials (pretty much whatever I want I can order through my school), a CNC machine, and soon a 3D printer. I have been working on the cross-sectional pieces (thank you for your short tutorial on generating those) and other various parts in SolidWorks by referencing the shapes off of 3D models and publicly available F-22 structural diagrams. If you guys have any of these buy the way I would appreciate them.

I still am very much a "noob" at electrical engineering (most of my knowledge is derived from these forums, Arduino forums, and my tour of the University of Arizona ECE lab, hehe). I look forward to seeing the progress of your model F-22, and I appreciate your contribution to these forums. Thank you.

P.S
I realize there may be some legal concerns here specifically with the kerfuffle I may face with the FAA regarding the civilian production of X-Band radar units for the purpose of targeting other aircraft. If any of you happen to be of the legal persuasion would you so kindly advise me to abandon this project. Thank you, haha. In the mean time I'll be checking for unmarked FBI in my driveway.

WOW Dude!

As far as avionics? wayyyyyy beyond what I have planned but It will have real turbines, thrust vectoring and the bays/doors will open to drop munitions. electronics is my dumb spot. but there are already off the shelf cheap products for telemetry, and video transmittal. not too long ago there was a system that used infra red transmitters and receivers to simulate gunfights. all cool stuff but way down the line as my priority is to get this beast flying for now. It will be interesting to see what you pull off. As the Japanese say... Gambatte! Go for it!

BELA wrote:

WOW Dude!

As far as avionics? wayyyyyy beyond what I have planned but It will have real turbines, thrust vectoring and the bays/doors will open to drop munitions. electronics is my dumb spot. but there are already off the shelf cheap products for telemetry, and video transmittal. not too long ago there was a system that used infra red transmitters and receivers to simulate gunfights. all cool stuff but way down the line as my priority is to get this beast flying for now. It will be interesting to see what you pull off. As the Japanese say... Gambatte! Go for it!

Hah, perhaps I am quite ahead of myself. My interest is just so piqued by the aircraft and your project that I'm just writing down all of the things I'd like to do.

You are correct there are dozens of telemetry and FPV units available on the market which make it remarkably easy to set up a near-realistic aspect of flying RC aircraft. My ambition is to eventually set up something similar to some high-end simulator cockpits (i.e multi-monitor, true-to-scale cockpit) in a comparable manner to how they are used in simulators. Alas, that is probably my fate but we will see. Laughing

On the topic of avionics, it's just so cheap (relatively) to get into using Arduino that it would be a crime to not try it out. A functioning x-band Doppler radar can be constructed for under $150, and that is just amazing.

Keep us updated on your progress, we (at least I am) are very intrigued in the advancements you have made thus far.

Are either of you adding fly-by-wire gyro-stabilized autopilot to help fly the aircraft?
The F-22 has relaxed static stability so it relies on the DFCS to move the surfaces.

neurotech wrote:

Are either of you adding fly-by-wire gyro-stabilized autopilot to help fly the aircraft?
The F-22 has relaxed static stability so it relies on the DFCS to move the surfaces.

Indeed, as that is beginning to become the standard in hobby aircraft these days. At my work (a hobby shop) more and more Ready To Fly and Bind 'n Fly (RTF&BNF) are hitting the shelves with gyro stabilization.

After market "fly by wire" hardware has been on the market for years now.

Ihatw to put so much importance on Arduino but it is just so versatile that there already several autonomous UAV open source flight control systems available for under $75. And as a result of being non-proprietary they are highly customizable. I have no doubts any of these hardware and software options could be adapted for whatever aircraft performance characteristics you desire.

Please forgive my poor typing, it is pretty hard to author a thorough response ftom a phone.

Again all of that is quite a bit out of my realm. The real Raptor is neutrally unstable not because of the shape as we always hear people say but because of the center of pressure center of gravity relationship. Arrange this properly for models and computers are not needed.

F-22, f-117 f-16 flanker models are all flying today without benefit of computers when the real world jets need them.
My goal is simply to do a model that really looks the part.
Radio control is actually fly by wire since it is not a direct input system, but not fly by wire in the context of relaxed stabilty control. There is a guy on youtube RCpowers that is always doing experiments with stability as it relates to rc jets. his experiments are very lo tech but useful and he talks about his results in laymans terms.

BELA wrote:

Again all of that is quite a bit out of my realm. The real Raptor is neutrally unstable not because of the shape as we always hear people say but because of the center of pressure center of gravity relationship. Arrange this properly for models and computers are not needed.

F-22, f-117 f-16 flanker models are all flying today without benefit of computers when the real world jets need them.
My goal is simply to do a model that really looks the part.
Radio control is actually fly by wire since it is not a direct input system, but not fly by wire in the context of relaxed stabilty control. There is a guy on youtube RCpowers that is always doing experiments with stability as it relates to rc jets. his experiments are very lo tech but useful and he talks about his results in laymans terms.

Yes I've heard of RC powers and I like to watch his experimental videos too. His comparisons of real life aircraft based on the performance of his foam model aircraft though are horrid. The quality of his videos have gone down considerably in the past few months.

I had a back-and-forth discussion with a few people on here over the PAK-FA performance and how much performance data could be obtained from the scale models (1/4 & 1/8th were in use). I'd probably go for a smaller F/A-18F model for my first real relaxed stability RC jet. Do you guys have any plans to make a large F/A-18E/F or a PAK-FA/T-50 model?

I have seen the open source ArduPilot in use before, it worked well.

I have modeled the Pak fa in cad as it sits today but have put it on the back burner til they have finalized the production standard, as least as far as the exterior is concerned. for example, If they plan on going to a raptor style thrust vector nozzle, It may require some changes, so that model for me is on hold.
It is a pretty bird, but there is just something about the raptor lines that I prefer. I will be doing some updates to the site and will include some pak-fa renders.

pants3204 wrote:

neurotech wrote:

Are either of you adding fly-by-wire gyro-stabilized autopilot to help fly the aircraft?
The F-22 has relaxed static stability so it relies on the DFCS to move the surfaces.

Indeed, as that is beginning to become the standard in hobby aircraft these days. At my work (a hobby shop) more and more Ready To Fly and Bind 'n Fly (RTF&BNF) are hitting the shelves with gyro stabilization.

After market "fly by wire" hardware has been on the market for years now.

Ihatw to put so much importance on Arduino but it is just so versatile that there already several autonomous UAV open source flight control systems available for under $75. And as a result of being non-proprietary they are highly customizable. I have no doubts any of these hardware and software options could be adapted for whatever aircraft performance characteristics you desire.

Please forgive my poor typing, it is pretty hard to author a thorough response ftom a phone.

Just an example of an RC aircraft with gyro

http://www.hobby-lobby.com/sebart_mig_2 ... 3_prd1.htm

see video further down the page

[url=[Link pending approval]]Modelado de radio de la aeronave[/url] controlada es una de las aficiones más emocionantes. Se trata de muchos intereses, disciplinas y habilidades. Algunos de estos son la aerodinámica, la electrónica, la mecánica, la redacción y el diseño, la construcción material compuesto y madera, y éstos están en el avión solo. Hay muchos otros campos de interés en la afición de los modelos de las aeronaves; demasiados y demasiado variadas para tratar de enumerar.

Recuerdos.
Andy.

Forum: General F-22A Raptor forum

6th scale RC F-22 model.