Jet Black BP100

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jetblackaircraft

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What does everyone think of the new Jet Black design? I am currently in production on the prototype, but at the same time I am putting all of my part designs into Pro Engineer to do CG calculations and fitment. Here is a screen shot of my pro E assembly of the entire aircraft (it's missing engine, landing gear, wing tips, some structure, but the CAD models of those are all coming soon. Tell me what you think! Oh, and if you want to buy one, go check out www.jetblackaircraft.com in the coming soon section for updates on projected completion dates, etc.



Single seat

Single engine (Cont O-200, Lyc O-235, Lyc O-320)

Aerobatic aircraft

Total kit price under $10,000

Performance:
Cruise: 170 mph
Stall: 60 mph clean, 50 mph landing config
Takeoff distance: 450 ft @ max gross
Landing distance: 500 ft
Climb at sea level: 1750 fpm @ max gross
Range: 700 statute miles
Endurance: 5 hours
G loading: +6.0/-3.0

Specifications:
Engine: 100 - 160 HP
Length: 18 ft
Height: 8.5 ft
Wingspan: 20 ft
Surface Area: 80 ft^2
Aspect Ratio: 5.0
Empty weight: 700-800 lbs
Max gross weight: 1200 lbs
Wing loading: 15.0 lb/ft^2
Power loading: 12.0 - 7.5 lb/HP


Not bad eh?
 

Jman

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Pacific NW, USA!
Very cool actually! I think it is just the angle I am looking at but the vertical stab looks larger than I am used to. Do you have a profile view? Congrats!! I can't wait to see the real thing come to life. Please keep us well informed.

Jake
 

jetblackaircraft

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Jake,

The vertical stab is a bit large actually. This is actually on purpose, the short arm of the empenage (about 10 feet) forces a slightly large tail to increase dynamic stability. It's not necessary, but I feel more comfortable sacrificing a little speed for some extra directional stability. The pro E rendering does make it look bigger than it actually is because it is an isometric and not a perspective rendering. I will get to work on finishing the CAD model so that I can post three-view drawings and some samples of the construction manual. I'm so upset that I missed Oshkosh with the prototype this year, but I think by next year (or maybe Sun n Fun) I'll have it flying and flight tested. (fingers crossed) Thanks for the input.

Mike
 

HeliDev

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Jul 7, 2003
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Sorry this is a bit OT, but Im curious as to how you did the lofts for the fuse in ProE.
I have only recently started using ProE, and have found lofing to be a real dog compared with my other cad progeams any tips?
Plane looks nice.
 

jetblackaircraft

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Lofting

So, by lofting i suppose you mean drawing the curves or profile of the fuselage? Sorry, I'm a bit of a youngster when it comes to aero engineering and have only heard the term lofting used when referring to the way that drafters used to use wooden sticks and weights to sketch the curves of an aircraft body. Anyway, in Pro E there are several ways to make features like extrusions, revolutions, etc. This is somewhat different from say auto cad where you draw the shape of the finished product instead of constructing it using methods similar to what you would use to construct it. anyway, when doing curved surfaces, there are two methods which have worked well for me. One is called a blend which basically takes multiple cross sections and places them at certain depths away from each other and connects them with bezier curves and fills in between these curves to make a solid or a surface. Another which is somewhat complicated to do and is only found in the wildfire version of pro E is called a variable section sweep. This involves drawing several lines which will make up the profile of the shape (top, bottom, left, and right, and anywhere else you want) and then drawing a cross section that touches those lines somewhere and pro E moves the cross section along those lines scaling it and changing it so that it is always tangent those lines. Hard to describe, but if you would like more info, please let me know, i might be able to post some screen shots.
 

jetblackaircraft

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Norman, OK
Lofting

Blend Example:




Variable Section Sweep Example:



By the way, you guys are getting a sneak peak at the Jet Black BJ400. A four seat single engine turbofan VLJ (very light jet) which hopefully some day will be flying. Some of the planned specs are cruise at 350-400kts, range of 1200-1500 miles, land below 100kts. A better picture of it is on my webpage. www.jetblackaircraft.com on the front page. hopefully by the time the new williams FJ44s are being sold used some of us homebuilders can buy them and refurbish them for something like this.
 
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orion

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ProE is better known for mechanical part design rather than the somewhat organic geometries we need for aircraft. In developing most mechanical parts, the geometry required can usually be composed of simple forms either blended together or "machined" away through the use of Boolean operations.

In creating more complex shapes, such as those we see in aircraft, the software needs a lot of capability in taking a variety of sub-shapes or controlling lines, and guiding the generation of the surface your are after. Even in the best of programs, this process can take several iterations before one gets just exactly the geometry one hopes for. If this is done in software that is somewhat ackward in this area, the process can be quite frustrating.

As far as the terminology is concerned, although "jetblackaircraft" is correct in that the term "lofting" used to refer to the creation of the various lines that define an aircraft (or originally, a ship), today it is generally used when refering to the creation of the surface geometry, not just the basic lines. In that process the term does include the creation of the all the intermediate line geometries required to develop the surfaces, but usually it refers to the surface creation almost uniquely.

The most difficult airplane geometries to create seem to be those associated with engine cowls (including things like cooling air inlets, nose extensions, etc.) and wing tips. For the latter the challenges are in assuring the tip root geometry not only accurately matches the wing panel's tip, but also matches the surfaces in terms of tangency and curvature. For this you need software specifically designed for this kind of control.

In my career I've used quite a few CAD packages (about 25 at last count), ranging from the high end systems used by the mainstream aerospace industry to some entry level drafting programs. I'm always surprised to see how a bit of finesse on the part of one package can substantially reduce the development time of any geomtry versus that of a less evolved system.

On the moderate end, I used to use Bentley's system (MicroStation) for some of my design work. The software was very cumbursome to use, to the point where I sometimes spent days modeling and tweaking just a simple wingtip.

Today I use Rhino3D, in which I can do the same work better and more accurately, in a matter of minutes. Aint technology great?
 

jetblackaircraft

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CAD software

I tend to feel like if you stick to one piece of software, even though it may have limitations, usually a good modeler can get used to the limitations and use creativity to still end up with what he wants. For instance, Pro E is usually thought of as a program to make simple mechanical parts, however, some friends at the University of Oklahoma used Pro E to design an entire race car. Frame, body, very simple aero package, etc. The ability is there to make anything you can dream up, you just have to know how to use it. Check out www.mcadcentral.com and look in the Pro E files at some of the things people have made. It's incredible. I guess my point is, people are using programs like Pro E to make complex shapes, so I'm not going to blame the software, I blame the operator (me) for any limitations.

Oh hey, I changed the cowl geometry a bit. Looks a little more finished now. Added a spinner. The pic above should have changed so check it out and see what you think!
 

Dieselfume

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S36 Kent, WA
The later versions of ProE have got better with the user interface, but it's still a [email protected] in several ways IMHO. I've spent many hours beating my head trying to get proE to do what i want for a class project... Doing the exact same process a few times before it does it right... Seems like I remember a fuselage that went straight then started tapering back. When the corners were radiused, it would never do the radius correct where it started converging, despite the curve starting tangent to the other section. It took forever to get right... If it were my money, I'd probably go after solidworks (although that's based on suggestions from friends) or something similar. ProE does do the simple shapes well. I sorta like the way you define dimensions in sketcher. Well, that's my $0.02...
 

HeliDev

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Messages
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Hey Guys,
Thanx for the replies.
Over the past couple of years Ive used a few programs, Rhino, autocad (yuck!!!), solid works, and I have a seat on alibre.
I have mainly started using proe because thats what they use at work and Im trainig my self in mechanica, so Ive been doing some extra modeling in that. Its only a trial version, I cant afford a seat.
On the whole I like ProE, but I find that some things are very easy, others are rediculously hard.
JB, thanx for those picks, Ive managesd to get the variable sweep going, but hte blends are a bit of a dog.
In my limited experience, I would have to say though that there are bits of each program that if combined would make a perfect progam.
 

orion

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The goal of any tool is to increase productivity and CAD is probably the best example of the potential to improve a product as well as the productivity it takes to create it. Many industries have dramatically improved their product development processes using the computer based tools. It is therefore of paramount importance that the tool they select does the job that they need. Not every industry needs the capabilities that we need in the design of airplanes. But many need specific capabilities to optimize their own processes.

But productivity is the function of the tool. I remember one company I worked for where the very expensive CAD system they incorporated was so counterintuitive and incapable that the engineers refused to work on it and went back to their drafting boards. By the same token, if you have to sit around, sometimes for days, scratching your head before you figure out workarounds to a particular problem, then it's very possible that you have the wrong tool. Part of this is of course the time you've just wasted on the problem.

But the second part is that in the workaround one often has to comporomise the design in some way that makes the mathematical model less than what it should be. Yes, the pictures you get may represent what you're after, but the model is not much good beyond the pretty pictures due to the lack of accuracy you had to work with in forcing the geometry to do what you were envisioning in your head. At that point yes, you'll get at least a representation of the shape but it will most likely not be accurate enough for you to build from. And it is at that point that the tool becomes less than beneficial to what you're trying to achieve.

The interesting part of all this is that some of the good tools are actually not all that expensive. Today we're getting more an more capabilities from design tools that cost a tiny fraction of what it used to cost for each seat of a CAD system. That enables even the smaller companies to get into the mix. I'll love to see what the tools will do ten years from now.
 

wally

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southwest TN.
Not much to add other than at my previous employment I used CADAM for several years to design simple bracket and part drawings as well as wiring diagrams.
Then I got a chance to take a 2 week course in CATIA. Wow, what a drawing system! Full-up 3D solid modeling. The instructor said it usually takes 6 months full time to get used to all the features, whistles and bells it has. The Gulfstream V was mostly designed using it.

Wally
 

jetblackaircraft

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CATIA

Yeah, CATIA is definately the premier modelling software currently in use. Several big time aerospace companies use it. I know people who got jobs based solely on their CATIA version 5 skills. If you have that on your resume, you're guaranteed a job no questions asked almost. I'd love to get a chance to mess with it. Don't have the money though, that's why I'm so into using Pro E and nothing else. I've tried autocad, solidworks, bobcad, and Pro E. Granted, that's not a very wide variety, but I can't imagine anything being much better than pro E. You can get a watered down version that you're not supposed to use for commercial applications for like $300. And I've never found a shape I couldn't make. It just takes a little getting used to the tricks, they may be counter intuitive, but they're only counter intuitive until you learn how to do them, then you see how they're not counter intuitive, it was just that you weren't allowing your mind to stretch the right way. Lol. lets see if I can sound even more like a hippy pothead. The software is always intuitive to the people who write it. Just because it's not to you doesn't mean it's bad software.
 
K

Kestas

Hi, folks, :)
Its my first post there, so let me introduce myself:
I am aeronautical designer from Lithuania now working as the CAA Inspector but still interested in development of ligh airplanes. My special field of interest is a 3D airplane geometry parameterization using CATIA V5 software. Before I was worked with Mechanical Desktop. I have short courses in local Aviation Institute (as my second/part time job) concerning airplane geometry modeling methods.
So, the basic operation commonly used is lofting of surface on the prepared 3D wireframe model. Blend and sweep operations are optional and used for joinings (fairings, cowlings). Basic lofting methods (named under a type of cross section curves used) are: radiusography, conic and spline methods. The last method (using spline curves for contour and cross-sections) is my favourite because it is comparatively simple and very flexible. Every method has its own smoothing technique of the 3D wireframe model followed with a final editing of the lofted surface. CATIA has very wide and powerful surface analysis/editing instruments in the Free Form block. Special task is development of seamless joining between a fuselage and vertical fin typical for composite structures.
I have uploaded some pictures in my gallery but failed to locate them there, sorry :(
I will be glad to be useful if somebody have any questions or suggestions.
Respect to Orion - I'v learned a lot of useful things from you :smile:
 

HeliDev

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CATIA is certainly one program I would like to have a go on. Unfortunately they dont offer a demo version, and the student version is only open to those who use CATIA at their university.
 

wsimpso1

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OK, I have looked, and maybe I missed it, but materials are used in its construction?

Being as I see a constant chord wing, and stringers and ribs in the fuselage, I am thinking aluminum. It looks like it will fit into the niche that used to be occupied by the RV3.

Billski
 

jetblackaircraft

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Materials

You are correct. It is an all aluminum structure with some fiberglass fairings. And yes, the target market is similar to the RV3. However, unlike the RV3, the BP100 will be all prepunched and precut. Should go together just about as easy as the RV6-10. If you have any other questions, or if I have left out anything important about the airplane which I may have forgetten to include,let me know. Thanks!
 
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