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3DHeavy Fighter

spacefighterspacefighter2 Posts: 0Member
edited March 2013 in Work in Progress #1
i am working on a sketchup model of a heavy fighter(i know sketchup is not the best of applications but it is easy to model with and i can convert the files and import into blender later), i have reached a point where i have a good idea of the basic shape as shown in this image
but am struggling to fill in the details as i think that there are too many large and boring flattish surfaces. i want to use similar shapes to my other designs ( search "send in the jagdpanther" on the google 3d warehouse) but i am not sure what to do, i do not really need help in knowing how to model the details but rather what to model.
thanks.
UPDATE: see page 9 for the seemingly finished model.
Post edited by spacefighter on
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  • SaquistSaquist1 Posts: 0Member
    It looks more like a bomber with 6 engines and heavy wingspan
  • spacefighterspacefighter2 Posts: 0Member
    that
    http://www.scifi-meshes.com/gallery/showphoto.php?photo=779&title=bloodhound&cat=all
    is an awesome ship! i am just not quite sure how to apply those sort of details to mine as it has curved surfaces whereas that fighter(the bloodhound) has flat angular surfaces, it is not so much a matter of how to add panels to these surfaces as a matter of how to do so and for the fighter to look "right" afterwards. thanks for the help so far.
  • songokusatsusongokusatsu61 Posts: 11Member
    if you want some insperation watch macross plus and look at the yf-19, your pic looks great but think is it going to be a multi role fighter, for instance can it fly in space or just the atmosphere or both consider perhaps folding wings for space combat as it wont need to be aerodynamic in zero g....awsome concept though great work!!!!!!!!!!!!!
  • songokusatsusongokusatsu61 Posts: 11Member
    plus if your having problems with hull plates you can get around that, as long as you can isolate the area with a texture you can create the plating via a paint tool like gimp or photoshop and use bump mapping and spec mapping to fill the void for you that way you dont have to worry about to much fine detail and you can keep the file size of your model down also :)
  • JafitJafit0 Posts: 0Member
    that
    http://www.scifi-meshes.com/gallery/showphoto.php?photo=779&title=bloodhound&cat=all
    is an awesome ship! i am just not quite sure how to apply those sort of details to mine as it has curved surfaces whereas that fighter(the bloodhound) has flat angular surfaces, it is not so much a matter of how to add panels to these surfaces as a matter of how to do so and for the fighter to look "right" afterwards. thanks for the help so far.

    I think that's an issue with choosing Sketchup, it might be time to think about trying to use Blender instead. You'd have far more tools and techniques available to you. Personally I have no idea how I'd add geometric detail to a curved surface in Sketchup, but I could do it in Blender.
  • Knight26Knight26191 Posts: 837Member
    I will have to find the tutorial for how I do texturing and link to you, it used to be on here. But design wise, this thing is a beast, but there are some definite issues. Assuming this an atmospheric craft having those engines way up there like that will require a large lifting surface ahead of them to counteract the thrust line, otherwise you will be constantly pitching over. If we assume space borne usage then you are in big trouble, that beast will constantly want to pitch over and will flip forward constantly as a result due to the engines being so far from the CG. You would do better to have two nacelles above and two below to balance the thrust. The two below could interfere with your landing gear though, so having them move somehow would be a good idea.
  • spacefighterspacefighter2 Posts: 0Member
    since reading this i have shifted the engine pods forward, so they approximately line up on the "y"forward/backward" axis with the centre of mass( look at my image then think of moving the pods forward, also i reduced the number of engines to 4, 2 in each pod) and am contemplating adding engines beneath the fuselage. this ship is intended both as an atmospheric and space craft but about your argument that the ship would spin in space due to the engines being so far from the centre of gravity i think thought that usually two forces were needed to make an object rotate (called a couple). in space when the engines fire there is a forward force due to them but no backward force on the lower parts of the fighter due to anything else thereby spinning end over end is unlikely. i have got nowhere near designing landing gear yet though.
    i can certainly see the similarities of this with that yf-19 craft.
    thanks.
  • Knight26Knight26191 Posts: 837Member
    Ok, guess I need to educate you a little on physics then.
    Here is a basic demo of Moments and Forces:
    Take a stick, ruler, pen whatever. Place it on a table, push on one end perpendicular to its length.

    What did the stick do? It rotated about its center of mass (CoM). Push on its center of mass, it moved in a straight line. Push on its center of mass and the end, it moved and rotated.

    That is what your ship will do, pitch forward because there is nothing to counter the moment arm of your engines. Let's give some real world and fictional examples, good and bad:

    Good:
    ST-TOS Enterprise. Matt Jeffries (an aerospace engineer by training IIRC, or at the very least an aerospace artist) knew a great deal about physics and incorporated that into the design of the NCC-1701. The impulse deck (acting very much like a rocket) was situated at the bottom of the saucer section, along what would have been the ships center of mass, given the displacement of the engineering hull and warp engines, he assumed the war drives were of significant mass, and the engineering hull largely empty space.
    Star Wars OT: Original trilogy star wars craft are another good example, with the engines clustered around the center of mass.
    VF-1 Valkyrie, Macross: The original VF-1 with FAST Packs shows how to place the engine away from centerline and still balance them. The main engines were lowered and the boosters had their thrust angled to keep them causing a pitch over since they were more powerful than the main engines (IIRC). If you also watch the animation you will see that with fast packs the VF-1 tended to fly nose high, because the new thrust vector was actually under the nose.
    Space SHuttle: The now retired space shuttle's main engines (SSMEs) were angled, and gimbled to compensate for that fact that during launch the space crafts center of mass was beneath the orbiter itself, and would move into the orbiter as fuel was expended from the External Tank and after SRB seperation.

    Bad:
    Jedi Starfighter SW EP2-3: Both Jedi Fighter are guilt of placing their engines well below the CoM, which should have resulted ina major pitch up issues.

    NCC-1701D: The D model enterprise had its impulse deck below the main saucer and in line with the engine nacelles, with a relatively tiny engineering hull below. This should have created pitch up issues unless main engineering was sufficiently high in mass to balance out the far larger saucer section. With saucer separation the problem would have been a seriously dangerous pitch down issue.
  • SaquistSaquist1 Posts: 0Member
    The majority of the mass of the Galaxy lies upon the stardrive with the heavier components such as the coils, numerous plants and deflector dish.
  • spacefighterspacefighter2 Posts: 0Member
    Knight26 wrote: »
    Ok, guess I need to educate you a little on physics then.
    Here is a basic demo of Moments and Forces:
    Take a stick, ruler, pen whatever. Place it on a table, push on one end perpendicular to its length.
    I understand physics well! in the case of a ruler against the edge of a table the table provides an upward normal reaction force to the ruler pressing down on it. when this is combined with your downward force at the other end the ruler rotates, now IN AN ATMOSPHERE you are probably right about the engines being too far from the centre of mass but IN SPACE as i said there is no force acting backwards on the bottom part of the ship so there will be no turning effect, notice how when ships rotate in space such as the space shuttle, or the starfuries in babylon 5, they fire thrusters on opposite sides of their centre of mass in opposite directions. if any force acting alone which had a line of action not passing through the centre of mass could cause a turning effect why would the shuttle crew waste fuel firing two thrusters when only one was needed.
    sorry about this rant http://01.2.3.9/bmi/www.scifi-meshes.com/forums/images/smilies/rant.gif , anyway i have added an engine pair on the underside. any ideas on how i could add details?
  • spacefighterspacefighter2 Posts: 0Member
    this is an image of what my fighter currently looks like.Attachment not found.
    note the engine pod below the fuselage. any ideas on what to do next?
  • Knight26Knight26191 Posts: 837Member
    Ok, I did not and do not want to come off as a prick but you are wrong. I am an aerospace engineer, and you got the point of the ruler example wrong. Place the ruler in the middle of the table. Now push on one end perpendicular to the length of the ruler, along the plane of the table, it rotates about its center of mass, regardless of whether or not another force is acting at the other end. In your example of the starfury the reason they fire both thrusters is to increase the thrust and therefore the rotational speed, because they have effectively doubled the length of the moment arm by doing so.
  • spacefighterspacefighter2 Posts: 0Member
    i can see that now but still have slight doubts that this would be a serious problem for a space craft, anyway i have added a pair of engines beneath the fuselage( see latest image).
  • Knight26Knight26191 Posts: 837Member
    That lower nacelle should help but in space issues with off axis thrust are exaserbated compared to in atmo since you do not have the atmosphere to compensate and provide lift as a counter force/moment. You can do the math pretty easily, find your CoM (your 3D modelling progam should give you a center of volume, which is close enough for what you are doing.) Then note the distance from centerline of each engine in the Z axis ( positive for up and negative for down), multiply by these values by the thrust output of each engine, assuming each has a different thrust output to get your pitch moment, postive or negative. You can then tweak your engines position/thrust to limit your pitch moment.
  • ZeropointZeropoint0 Posts: 0Member
    Think of it this way: if you had a model of your spacecraft, and you put your fingertips on the engine nozzles and tried to balance it nose-up, could you do it? If not, it won't fly straight in space.
  • Knight26Knight26191 Posts: 837Member
    Zeropoint wrote: »
    Think of it this way: if you had a model of your spacecraft, and you put your fingertips on the engine nozzles and tried to balance it nose-up, could you do it? If not, it won't fly straight in space.

    Nice example.
  • JafitJafit0 Posts: 0Member
    any ideas on what to do next?

    I've noticed that you seem to keep asking this.

    I would suggest that you sketch out some concept drawings of what you want the ship to look like when you're finished. Details, shape, etc. Even better print out a picture of what you have now and use it as a base to draw on.

    The problem with 3d modelling is that unless you're quite experienced with it, it's very hard to go from nothing at all to something that looks good, because when you're modelling you are preoccupied with solving a bunch of logical 3d problems. When you draw you are free from the constraints of the mesh and can let the creative side of your brain take over instead of the problem-solving side holding sway.

    When you know what you want it to look like you can get back to problem solving.

    If you can't draw at all and can't even attempt to sketch out some details to model, then I'd suggest calling this one done, finding some existing concept art and trying to model that instead.... while learning to use something better than Sketchup preferably. Seriously. Sketchup is ****-tier 3D software. Upgrade to Blender.
  • songokusatsusongokusatsu61 Posts: 11Member
    glad i could help in some way got to love isamu dysons yf-19....
  • calamity_sicalamity_si361 Posts: 369Member
    I like this design, it looks like it would be quite at home sitting in the hangar bay of my S.S. Argonaut ship!

    I'm actually had similar problems modelling that in Sketchup. It's a very basic program and I've noticed that when you try to add individual pannels etc, it really beefs up the memory usage and if it goes over 8 (or maybe 10) mb then you can't upload it to the Trimble warehouse. If you're looking for panels though, have you tried enabling the 'view hidden lines' option? Once you can see the individual pannels, you can then pull them out a bit to add some surface texture.

    For a large ship like the Argonaut, I'm trying to give the impression of size through adding 'greeblies' such as antennae dishes and arials and small blisters just to break up the surface a bit. Also, never underestimate the impression a good paint job makes!
  • spacefighterspacefighter2 Posts: 0Member
    I like this design, it looks like it would be quite at home sitting in the hangar bay of my S.S. Argonaut ship!
    good to see you like it, i am getting back to work on this model after doing other things for a few weeks.
    it currently looks like this
    Attachment not found.
  • spacefighterspacefighter2 Posts: 0Member
    altered the nose,Attachment not found.. the new nose is lower but there is still some space below for the intakes of the underside engines. going to need to rethink landing gear.
  • spacefighterspacefighter2 Posts: 0Member
    started on landing gear but i am having some difficulty getting it to look right, i would want some form of hydraulic ram in the space above the landing gear frame but there is no space, any ideas on how i beef up the undercarriage whilst still designing parts that would in reality fold up and down correctly? no ideas for the rear gear yet(argh)!Attachment not found. see what i mean? i cannot lower the fuselage any further due to the engines underneath it and the downward pointed wings.
  • Knight26Knight26191 Posts: 837Member
    I like the new nose, very F-111ish. As for the undercarraige I need a better shot of it from underneath. But if you can't fit all the hardware in the bay, put it behind it, like on the F/A-18 nose gear
  • cavebearcavebear179 Posts: 623Member
    Hey there spacefighter,

    Gotta jump in here. As an aircraft tech for the last 24 years of a career now in its 28th year, there is no way a nose gear would look like that, be that small, have that angle, nor have 4 tiny mini wheels. Knight26 is on the mark when suggesting this:
    Knight26 wrote: »
    ...put it behind it, like on the F/A-18 nose gear

    Disclaimer FYI: I worked on Canadian F18's in Cold Lake Alberta for 8 years.

    For the size of the craft I would go with 2 nose wheels on the landing gear like the F18. Also when you see what is really in front of the pilots station on a real fighter, you would have no room for the landing gear of the size you really need.

    Aside from that one crit, I do like the general shape of the fighter...but (sorry :)), the engine exhausts are very small and stick out like a sore thumb. I'd go with two larger engines. Again, like Knight26 mentioned, check out the F111 for ref. That and the F14 or many of the Cold War Russian designs like the TU-22. Okay...now I'm done :D
  • spacefighterspacefighter2 Posts: 0Member
    i know that the forward landing gear does not look right, so am working on changing it. the problem is finding the space. the design of the nose is based on an f111 , but i will not be changing the engines as i think they look good in that arrangement( i am not sure which engines it is you say have too small an exhaust as there are 6 ramjets (in pods of 2) with large exhausts(perhaps not visble in my images and a number of smaller booster rockets in the rear designed to be removed and replaced(slide out and bolt in a new set) once used.).
  • cavebearcavebear179 Posts: 623Member
    Referring to the booster rockets in the back. They really just look wrong. I have nothing against the pods at all.
  • spacefighterspacefighter2 Posts: 0Member
    changed the blasted undercarriage , have yet to redo the nose wheel. the parts are designed so that by rotating a few things the wheels can deploy. they are somewhat small but i could not fit larger ones in the spaces available so the alternative was ridiculously long and spindly landing gear from parts of the fuselage that are further from the ground. this should not matter as when the fighter lands it can hover on "ion columns"(pillars of gas held in place by an ionised tube around them, using the ionised tube to prevent the gas escaping so it will compress inside the tube and then support the fighter), as the fighter is rather heavier than my other designs(also fitted with ion columns) it is helpful to have wheels rather than pads to support it once it is landed. this means that when carrying large loads of weapons it can make a short take off along a runway rather than trying to rise up on the ion columns which would(without being made more powerful and bigger) be unable to provide enough force. pictures of the changes are below.
    Attachment not found.
    Attachment not found.
  • spacefighterspacefighter2 Posts: 0Member
    thinking about where to place the entrance/exit from the cockpit. i appear to have two options, a hatch in the floor of the rear of the cockpit leading down and out through the back of the landing gear bay( the area where i would put the hatch is not in the way of the gear and is not inaccessible due to the position of the gear when folded or lowered), or out through the side of the back of the cockpit. i was not intending to have the canopy open and want a way for the crew to enter/leave the craft easily without the need for ladders etc so some form of steps needs to be included in whatever type of exit i choose. to clarify, in the image the floor and through the landing gear bay hatch would be somewhere through the floor behind the seat( i will put in the copilot/weapons operator seat later somewhwere behind the pilot). the side exit would be a folding door in the hull of the craft also behind the pilots seat.

    which should i do?
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