noob here, pls be patient.
so i'v fount this jet engin online and i'm a bit confused with one charactiristic:
Fuel Consumption = 1.2 kg/daN.hr
does this mean that this engine will produce a constant thrust of 1000 Newton while running for 1 hour and only consume 1.2 kg of fuel ?
sounds pretty economical. or am i reading it wrong ?
Pretty sure da is deca, which is 10, not 1000.
>>1017838
you are correct, but the engine will never ONLY produce 1000 newton, so you need to multuply the 1.2kg by whatever output the engine has
http://www.pbsvb.com/customer-industries/aerospace/aircraft-engines/tj-100-turbojet-engine
This thing is way bigger than I thought it was from OP. I thought it was one of those "bolt on your bicycle" kinds.
>>1017843
you're right, my bad.
that sounds more like an jet engine fuel consumption.
so 1000 Newton of thrust over an house would actually take 120 kg of fuel.
>>1017846
it has a max thrust of 1300N according to the manufacturere.
>>1017853
indeed, its not an RC engine, its design for light aircrafts and 292lbf of thrust should be enough to take a guy for a spin.
>>1017853
Holy shit. That's serious business. OP, please share your plans. I dont care if its air or ground, fast is fast.
>>1017880
lol jetfighter???
>>1017880
I hope you REALLY know what you're doing OP, because fighters are crazy unstable and require flight computers to fly.
Not to mention, you're gonna need to register it and get a pilot's license.
>>1017896
already know that.
that being said, its way too early for that.
i'm still checking for the requirement and components.
and not all jetfighters are unstable, most are designed to be for agility reasons.
also they can afford to be unstable with an over powered engine. i can't.
mine would be as stable as a 747.
will have allot of lift and will most likely not go faster than 600 kph.
as for the material, it'll be as lightweight as it can.
i don't have to deal with hypersonic speed, high heat and crazy pressure from cornering. i don't have to go with insanely exotic materials.
aluminum and carbon fiber will be the main component of it.
i doubt the plane itself would weight more than couple hundred kg.
but like i said, its still early.
If you plebs don't vote this banner to win the Banner Contest, I will buy enough 4chan masses and vote it until it wins.
Bonus, the Passes look neat.
>>1017915
make it win.
>>1017915
Voted.
OP, why are you here instead of on experimental aircraft forums?
That you would even think of asking advanced aviation questions here instead of where you can get ample professional advice suggests you are fucking clueless and it isn't being mean to say it.
It begs the question why you didn't call the MANUFACTURER for technical support and would use a weeb forum instead. That way past the wrong way to do it and well into mongoloid territory.
If you are serious, you'll get detailed information from those best able to provide it. First, unfuck your thought process and learn thoroughly about aviation, aircraft construction, and what parts of that construction you might do yourself.
Start here: https://www.eaa.org/eaa Think "professional". What you say you want to do absolutely requires it.
Aviation has a lot of fun career potential. Most experimental builders are in the business or retired from it.
Go to the EAA meet at Oshkosh. It's amazing.
>>1017928
>OP, why are you here instead of on experimental aircraft forums?
good question.
i'm still not in it yet, just lurking, getting some infos on what i need, see if i can afford it.
>It begs the question why you didn't call the MANUFACTURER
for that silly question ? it's not worth bothering the manufacturer.
>Go to the EAA meet at Oshkosh. It's amazing.
thanks for the link m8, i'll definitely check
>>1017961
How old are you? What have you built before that prepares you for this? Building a jet is not like building a bike, or a table, like we plebs do. It's a fucking jet. Like, the ones many people have died in, and those were built by professionals.
>>1017853
hold the fuck up
Does this thing have the engine retract when its not in use? Thats neat as hell
>>1017969
>How old are you?
32
>What have you built before that prepares you for this?
i'm a CAD designer, i use Solidworks daily for my job, also use Ansys in my spare time.
i build RC planes as hobbie.
i also use xflr5 for small project.
don't worry, i won't be using any plane before months or even years of tests and aerodynamic simulation.
>>1017983
Good background.In that case you REALLY should invest in an "aviation vacation" in the US and enjoy the experimental and vintage aircraft communities. (The vintage guys do a lot of interesting fabrication.)
I can't post the Fighter Factory fecesbook link due to spam filtering. Check 'em out. They are in Virginia.
If you can human network some experience in aviation repair and maintenance it will give you the tactile feel you need for the job. Reasonable humans won't mind volunteer help at small facilities and it would be worth pushing a broom and helping with cleanup. You might barter your CAD skills for assistance with your project. I would certainly mention it and you could get involved (perhaps heavily) in the aircraft community years before building your own.
You understand the meaning of tactile experience from model building, but aircraft are a much different experience in that respect from models or automobiles.
I've been variously an avionics tech, engine mech and crew chief in the USAF. I'd have liked to get structural repair experience but missed out on that. I suggest you get some experience with the materials you plan to use.
I recommend you take manual and CNC machining courses. You'll breeze through the math since your're experienced with CAD, and machining will give you a needed "sense of metal" WELL beyond what you'd get spinning a wrench. It will make you a better CAD designer.
>>1018029
I posted this to a military study group. You might find it useful when designing your bird. The sentence in quotes was regarding speciality quick disconnect fittings. Pardon the formatting.
"It costs money up front for all of the disconnects
vs. standard fittings but in the field it save time
and lives."
QDs have the disadvantage of more complexity than
standard fittings.so I'd save them for special
locations like main fuel lines.
When we do need them they don't always arrive from
Supply as quickly as generic parts.
Standard fittings that aren't buried in a rat's nest
of other stuff will work fine and be easy and cheap to
replace. I'd be delighted if we can whip out most
spare hard lines from stock with hand benders and
flaring tools.
I'm fond of easy-to-access lines (with different sizes
for adjacent lines to prevent mis-connection) and
plenty of room for a line wrench/torque wrench with
crowfoot.
I'd like an easily disconnected throttle shaft that
doesn't get sloppy, is easy to rig, and stays in rig.
Ditto the cockpit quadrant.
If we minimise the different size/types of rig pins
that would make life easier, as well as authorising
rig pin replacement with a specified drill shank size.
If our torque specs, where we can, allow use of
deflecting beam torque wrenches we could minimise
trips to the calibration lab.
We want to make flight control connections easy to rig
and dumbass-resistant. The F-15 that crashed due to
crossed control rods is a sad reminder that "word of
mouth" does not substitute for tech data, and tech
data does not substitute for not being able to connect
'em wrong in the first place.
I'd like to minimise the VARIETY of expendable,
consumable parts. Less bench stock = fewer supply
hassles. The smaller variety of things like light
bulbs the better.
>>1018035
continued:
I have major loathing for engine wiring harnesses like
the Pratt engine harnesses which are wrapped in steel
braid. Plastic split-loom, string ties, and Adel
clamps are good stuff and allow field repair.
I know it's a hassle, but long wire runs should be
laid out and clamped for simple harness removal.
Fishing them out and rethreading them should involve
as little suffering as possible.
Control cables if possible should be replaceable by
making them from bulk cable and fittings in the field.
Fittings that don't need safety wire are good, because
many troops can't safety wire well, and the cutoff
ends are FOD.
Cotter keys are OK.Many different cotter keys are not
OK, unless they are easy to dyke from the longest key.
Phillips and Reed and Prince screws are easily
stripped therefore evil.
Tridair fasteners are nice to deal with, as are Allen
fasteners generally.
Color-coding and visible labels are good.
Wiring harnesses that require multiple cockpit control
boxes to be removed so your hand can reach the
connector on the one you are removing suck.
Easily removed glareshields that allow access to
instrument panel wiring are good.
Torque-tip fasteners get wiped because the
lowest-bidder shite TT bits from Supply are made of
sintered bread crumbs...but they are better than
Phillips or Reed and Prince screws.
F-16-style snap-latch panels when oriented so the
airstream tends to close them are good.
Old-style Cannon plugs and electrical connectors that
require safety wire are evil.
>>1018036
continued:
Threaded Cannon plugs will stick, will be removed with
metal pliers when the soft-jaw pliers slip, and will
get trashed. If they are REALLY stuck, someone will
use a hammer and screwdriver...
Radio and avionics LRU mounts that have a built-in
electrical connector should be easy to remove to fix
damaged connectors.
Leads on harnesses for LRUs that have connectors
requiring disconnect before the LRU slides out of the
rack should have length/room to swing out of the way
and not get snagged.
Most of our LRUs will be standard, but location,
"mounting of mounts", and harnesses are variables.
Coax cable runs should have enough length for at least
two connector replacements.
A nice thing about the OV-10 is we could often
fix wires with the famous pink crimp-on butt splice.
When connector replacement required cutting the old
harness, we could crimp on a an extension with the new
plug already attached.
We have heat-shrink solder splices now, but crimping
is quicker and safer.
Why safer? When heat guns for solder splices break,
cigarette lighters are the replacement.
------------
I didn't design aircraft but I've repaired and maintained my share. Make your bird not only reasonably easy to build, but easy to maintain and modify and you will be much happier than otherwise.
>>1017899
Praise kek, I hope you don't have any experience as an aerospace engineer, for the real /diy/ deal.
>>1017899
>carbon fiber
I seriously hope you're not using carbon fiber for the frame.
I've seen commercial all carbon fiber planes, and they're still only in the prototyping stage.
>>1017983
>i'm a CAD designer, i use Solidworks daily for my job, also use Ansys in my spare time.
>i build RC planes as hobbie.
>i also use xflr5 for small project.
>don't worry, i won't be using any plane before months or even years of tests and aerodynamic simulation.
I have been building high powered electric motor controllers recently, I was thinking about something similar recently but I don't have the aircraft skills to do anything. I assume one of the biggest problems with a small DIY jet is the high stall speeds and the compromise between low speed stability and drag?
The thing is most people don't realize how crazy the power to weight ratio of brushless motors has become, you could have around 200KW of motors for 35kg but battery tech isn't good enough to supply that much power for flight. So for a lightweight jet rather than compromising the design for low speed flight, what if you just abandoned low speed performance and make it take off like a giant quadcopter? There's plenty of ways to build the electric thrusters so they don't take up too much room or compromise aerodynamics. You would have to attach electric motors to the turbine shafts to act as generators so they can power it for take off. There's other advantages depending on how the electric thrusters are configures you can also use them for lower speed flight where turbo jets are less efficient. As the generators can act as motors you can also shut down turbines when power isn't needed then restart them.
Ignoring the technical issues, what would a small personal jet look like if you didn't have to worry about low speeds? With something like a 400km/h stall speeds would you be able to make a much more efficient design?
>>1018181
only the external shell would be made of carbon fiber, the structure would be made of aluminum.
>>1018217
been reading about plane aerodynamic and physics yesterday.
i always thought that the center of gravity and the center of lift had to be in the same place, turns out they aren't and now i'm even more confused
Study all the Burt Rutan aircraft and how metal and composites are used in proven fighters like F-16.
The Bede jets had a high loss rate, but many pilots were inexperienced and they have a high stall speed. Their construction is interesting.
I suggest you build a Burt Rutan design as practice. You may end up modding one of those instead of building a clean sheet design.
If you try too many exotic technologies at once you won't go anywhere when one implementation doesn't work as planned.
Be careful of the theoretical trap of falling in love with how something looks in theory. Find out how it works in practice because you will be flying in practice.
One surface, one component, one nut, one bolt or one wire can easily put you in the dirt if it fails.
Ensure you have a fast canopy jettison. You can't afford an ejection seat or its weight, but you should leave room to wear a parachute.
You could include a drogue gun, or even an aircraft recovery parachute since they work best on little birds.
This thread happens every week. When it comes down to it, one person cannot build a large aircraft. These things are designed and built by organizations with thousands of team members working on different components, and these are some of the best minds in industry.
Therefore, my first peice of advice is to give up. You, OP, need to readjust your goals to make this reasonable. I would suggest building an ultralight or gyrocopter. This will not only be extremely informative, but you may in the process realize that your dreams were different than upon first introspection. Not to mention a much smaller financial burden if you fuck up.
>>1018289
He's certainly not going to do a big bird in the first build. The little ones take several years, and are typically built on top of a varied career in closely related discipline(s).
He will learn the deal breakers as he researches the problem, scale back his expectations, and just maybe produce a homebuilt.
The people who succeed are those who eat, sleep and breathe aviation, get formal training and are fucking fierce autodidacts. They usually have very advanced home workshops, and if you want to fuck with composites you will have to do that.
A clean sheet baby jet could easily cost more than a million dollars if you add everything up. You don't do this to get an inexpensive aircraft. You do it because you want as a benchmark for your skills which you can fly. It's not a way to get low cost flying hours either. That money could rent a variety of aircraft for many more hours you wouldn't have to build or maintain. Know that in advance so you don't mislead yourself. If you want to build, build. If you want to fly, crunch the cost/flying hour.
It's so consuming most builders are middle aged or older and very comfortably retired.
I could build, but not design unless I went for an appropriate degree, an all-metal homebuilt but it would still be very expensive and take several years. (My vision sucks and I have other medical issues which would keep me from passing a flight physical so that's off the table.)
>>1018309
>He's certainly not going to do a big bird in the first build.
why the fuck not ?
https://www.youtube.com/watch?v=V8C0T1y9_yw
stop being a demotivational cunt, a single person aircraft is perfectly doable.
>>1018794
That Archon isn't large and isn't a fucking jet. It uses a Rotax piston engine:
http://www.aerosports.gr/index.php/specifications
OP was asking about a JET which he proposes to DESIGN and is a considerable leap from a piston engined KIT. Archon looks to be a nice kit:
http://www.aerosports.gr/index.php/links
Perhaps English isn't your first language. I've been suggesting how OP might realistically have a shot at building a JET (capital letters so you can see them better) from his own design. That is an exceptionally difficult project. It's been done, but it's far from common hence my suggestion to meet EAA members.
He could certainly learn from building an Archon and might actually get to fly the thing before he dies of old age, but that wasn't his question.
>>1018966
i'm sure OP's ambition isn't an F-35, and acording to his spec (tj-100 engine) its would perfectly fit in an Archon like.
OP never said he wanted to build a Mach 2 capable jetfighter.
nobody said it was easy but its definitely doable.
>>1017880
>trying to build my own jetfighter
Is this real life?
>basically trying to build my own jetfighter with two of those puppies.
it obviously wont break the speed of sound but it will look badass.
Twin means BIG for a homebuilt and CUSTOM, not a kit. OP is clear about his objective.
OP, are you rich? Yes or no. Sorry to break DIYtard hearts but if you want to play in the fucking big leagues you need to be able to shit considerable cash and if you can't do that, adjust your dreams to reality or adjust your reality to your dreams.
Here's an example engine:
http://www.ez.org/t/Longez-jet
Interesting Rutan design modded with a jet:
http://eaa1541.org/?page_id=1087
Noob status is curable. It takes about five to seven years to go from "noob with aptitude" to a highly proficient aircraft mechanic or technician. I've trained plenty of them. What OP proposes to do involves a drastic lifestyle change, not just putting parts together.
The usual "gee dis is kewl, why can't I make one from pallets running biogas made from imitation crab meat" idiotic bullshit won't fly, pun very much intended.
I wrote at length because OP just might make an aircraft. Homebuilders have to come from somewhere. Some are doctors or dentists who use their learned ability to learn to learn new things. Of course doctors and dentists understand the concept of precision and how to envision object interaction in 3D space. They typically have fine motor skills required to build aircraft efficiently.
Aviation is fun. Aircraft people who do well are a smart bunch and fun to be around. OP or anyone else seriously interested should stick a toe in the water, and because the aircraft trades are mentoring cultures it is important to get as much direct experience as you can. You could volunteer at an aircraft museum for example. If you are eager, bright and determined you'll enjoy the challenges.
"I want to homebuild an aircraft" really means "I want to become an aircraft person (aviationist?)".
>>1019304
>OP, are you rich?
i'm comfy.
could definitely spend up to 500k to 800k in it.
this engines cost about 41K each, i'm pretty confident that the whole thing will not cost more than 200k in the worst case.
thanks for the links btw, i really appreciate.
its really hard to find engines over 300lbs for sale, let alone at acceptable prices.
i'm still looking for a more powerful engine that the tj100.
>>1019382
Team up with turbine dude and make the engines yourself
>>1019398
designing a plane is one thing, designing a turbine is another.
thats a whole new level of complexity, man.
you need to master fluid dynamics and thats just for the design, not even talking about machining the components together.
Inconel and Titanium are a pain in the ass to work with.
it would literally take years to get a working engine.
desu i don't have the knowledge nor the time for it.
i want to be able to fly that thing before i'm too old and fragile to do it.
Wow, OP sounds pretty sensible as far as OPs go. Good luck.
>>1018794
The US military has fallen on hard times.
>>1019661
kek
>>1019435
You think youre gonna whip out a functional aircraft in less than a few years?
>>1017899
>mine would be as stable as a 747.
Ok
>>1019788
Not him, but building a functional aircraft wouldn't be too difficult if you're pulling all the parts together and not designing from scratch.
Building a reliable aircraft in that time frame though, would be nearly impossible considering that he is just some random dude.
>>1021228
I had assumed he meant what he says and will actually be designing, fabricating, assembling, testing, licensing, and then flying.
Has OP even got a thousand hours in flightsim, is what I'm wondering...
