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3DMK iv fighter

spacefighterspacefighter1 Posts: 0Member
edited February 2013 in Work in Progress #1
i have nearly finished a slightly modified version of my admiral peck class mk iii space/air superiority fighter "HellHound"http://sketchup.google.com/3dwarehouse/details?mid=839d5a9990089b8bfbace48d228f8fc3&prevstart=0. i armed it with a bigger weapon under the nose ( a gatling laser, this may sound strange but the principle as explained in my description makes sense(i hope)) . i also tested to see what it would look like in a standard grey rather than a squadron leader red. i have almost finished( could argue just done) so am unlikely to make many changes before i finish it completely but i would like to know what you think.
http://britishstarfleet.blogspot.co.uk/p/admiral-peck-class-spaceair-superiority_29.html
the blog page is at this address, you can follow the links to download it.
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enjoy the image as well.
note to self: must start some totally new designs.

UPDATE: see the most recent post for my animation
Post edited by spacefighter on
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  • spacefighterspacefighter1 Posts: 0Member
    Attachment not found.
    the control panel for the mk iv fighter, i can almost manage to remember what each switch does!
  • spacefighterspacefighter1 Posts: 0Member
    Attachment not found.
    a diagram of which switch does what.
  • Knight26Knight26189 Posts: 833Member
    Are your pilots left handed? In general a fighter always has its throttle on the left hand side, with only side by side seating cockpits having the throttle in the middle. Also, like your bomber, how are you planning to compensate for the torque/moment arm of those upper engines, especially out in space? Your wing configuration should help with that in atmo but your fighter will still want to pitch forward a lot due to that placement.
  • spacefighterspacefighter1 Posts: 0Member
    i never thought about left/right handed pilots but from thinking about where the levers and joystick are placed it would appear to be a fairly effective layout( just not the standard one that is used at the moment i guess). with the booster engines i never really intended them for use in an atmosphere ( look how powerful they are 4x10^17 Watts, i calculated the power needed by the main neptune engines to reach my desired "top"( a spacecraft would not have a top speed as such, although there will come a point for one where near to the speed of light at which the mass becomes so great due to M(apparent)= M(rest)/(1-v^2/c^2) that the acceleration will become negligible. i never really thought that considering it has a hyperspace drive it would need to go any faster than 0.8c) speed in 2 minutes from e=0.5mv^2 ( i am quite good at physics despite my mistake with engine positioning)then added a bit of extra power to the triton boosters), in space the problem of the boosters being a little bit above the centre of mass could be solved by using the thrust directing fins in the rear of the engines to angle the jets of deuterium/helium plasma up or down. are there any other ways you suggest i solve this?
  • Knight26Knight26189 Posts: 833Member
    The problem with your arrangement is that for a fighter you don't just set the throttle and go. You adjust it constantly, especially in a fight, and if you have to pull your hand off the stick to do that you are in serious trouble. I would also say to keep your hyperspace lever where it is, out of the way so you don't accidentally actuate it when working the throttle, assuming it does not have a physical lock out.
    Why are you displaying your power output in watts? Is that the power of the reactors? What is the force out of the exhaust? Watt is a rate of energy transfer. Your thrust would be in Newtons.
    Now to correct for your boosters, you will want to angle the thrust from them and the mains such that the thrust vector is through your fighters Center of Mass (CoM). You will loose some of your forward thrust as a result, but it will keep you on a straight line, just remember that that straight line, depending on the amount of thrust the engines put out, might not be along the nose, but could result in your fighter flying with a nose high or nose low attitude relative to its direction of travel.
  • spacefighterspacefighter1 Posts: 0Member
    ok, the throttle can be adjusted with the right hand whilst the left hand controls the joystick( this might not be standard at the moment but it would work even if the left hand is usually a bit weaker and less precise than the right). with the hyperspace lever i thought it would be best to have it further to the left so that it is not knocked( as you suggested), the power output is in watts as power is energy per unit time ( joules per second and therefore watts) this output refers to the engines although there is a dial on the control panel to show the output from the reactors as well. also most engines produce a certain amount of energy per second when operating a top speed, this output i have mentioned refers to the rate of converting mass energy( released by the atomic nuclei being fused) into kinetic energy of the fighter ( the energy is transferred to the exhaust gas as kinetic energy after being converted from mass energy in the nuclear reaction, the exhaust gas therefore has a high velocity at which it leaves the rear of the engine. through conservation of momentum the fighter will gain momentum and in doing so gains kinetic energy, it is this energy gain by the fighter per second which i have quoted in watts. i know that some of the mass energy will be wasted as heat and light in this process so the power of the engines i have quoted will be slightly less than the actual amount of energy being released from mass in the fusion process). I was not quoting thrust but POWER which is the rate of energy transfer and therefore perfectly acceptable to quote in watts. i do know about adding vectors so can now calculate using some trigonometry what angles the exhaust gasses would need to be directed in as they leave the engines, this would be achieved by lining up the vectors of the thrust so that the up/down components are equal and cancel( i think i would be correct in assuming that the thrust force would be proportional to the power so we are asking what angles are necessary to line up a vector of magnitude 8( from the two boosters) and a vector of magnitude 4.8 ( from the two neptune engines) so that there is no overall vertical component.). writing it as "you will want to angle the thrust from them and the mains such that the thrust vector is through your fighters Center of Mass" really helped, thanks.

    started on the calculation
    4.8x10^17 sin(alpha)= 8x10^17 sin(theta)
    so lets set a low value for (theta) the angle down from the forward backward line at which the boosters are pointing
    8x10^17 sin 5= 4.8x10^17 sin (alpha)
    then
    (alpha)= arcsin((8x10^17 sin 5)/(4.8x10^17))= 8.35 degrees
    so when the boosters are pointed down by 5 degrees the main engines must be pointed up by 8.35 degrees(assuming the centre of mass is midway between them).
    i will refine this for where the centre of mass actually is.

    just thought of a problem with that, the fighter is designed to fly most of the time without using the boosters therefore the centre of mass should be somewhere between the neptune engines, as they are a distance of 0 away from this point on the z axis it means that it is probably impossible to run the thrusters without somehow "unbalancing the fighter".
  • Knight26Knight26189 Posts: 833Member
    ok, the throttle can be adjusted with the right hand whilst the left hand controls the joystick( this might not be standard at the moment but it would work even if the left hand is usually a bit weaker and less precise than the right). with the hyperspace lever i thought it would be best to have it further to the left so that it is not knocked( as you suggested),

    Okay that statement right there will make every pilot out there hate your guts. Pilots, as a general rule, will almost always refuse to let go of the controls, and forcing them to switch hands while in a manuever will result in death basically, or so they will will insist. My buddy Pete used to say it like this this: YOur left is your thinking hand, it controls the throttle, you think with that. Your right is your action hand, it reacts to what is going on around you, and keeps that stick in hand because you don't dare let it go or else the plane gets away from you.

    Also in combat you are constantly adjusting the throttle and stick, so you want to keep your hands on them at all times, that is why HOTAS (Hand On Throttle And Stick) was such a major improvement in 4th gen fighters, it allowed pilots to do almost everything they needed without having to reach up and touch other controls while in combat.

    As for your thrust figures, I would really have to look at those more to give you better insight. A diagram of a side view with all the relavant numbers would help in that regard. i.e. Distances, locations of the CG/CoM, thrust figures etc. I could then easily figure out your thrust angles and numbers from there, but I need the thrust as a measure of force (newtons), not energy (watts).
  • spacefighterspacefighter1 Posts: 0Member
    i wasn't suggesting that the pilots let go of the controls and swap hands rather that they always have right hand on throttle and left on the stick. about the thrust i noticed that on my thread about the heavy fighter Zeropoint said"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.". you then described this as an excellent example. as it happens i do have a 3D print of my MK iii fighter and i found i was able to balance it on four pins( one below each neptune ramjet and one below each triton booster), i also found that it could be balanced on two pins( one below each neptune engine). i am aware that as the triton boosters produce ( i would assume that the thrust is proportional to the power( is it?)) 4"units" of thrust for every 2.4 "units" produced by the neptune fusion ramjets this is not perfectly accurate.Attachment not found. with all four engines supporting it
    Attachment not found. the fighter supported by the "thrust" of the fusion ramjet engines.
  • spacefighterspacefighter1 Posts: 0Member
    last night i realised that there was a simple method for solving the problem of turning effects on the ship caused by the thrust vector not necessarily passing through the centre of mass, MOVE THE CENTRE OF MASS!
    I came across this remarkably simple idea when reading some of the articles on http://www.projectrho.com/public_html/rocket/landing.php i came across this passage


    by Robert Heinlein

    i have now come to the conclusion that the best way to ensure the thrust vector is through the centre of mass is to move the centre of mass by shifting a very dense( like 1kg/cm^3 density) liquid of some kind between a number of small tanks in the wings of my fighter. this can allow the centre of mass to be shifted from a point which allows the Titan neptune fusion ramjet engines to power the craft without creating turning forces to another point higher up which will allow the Titan triton ramjet boosters to provide thrust of ratio 4 : 2.4 with the neptune engines still with no spinning problems. this can also counterbalance any lightweight cargo placed in the rear or pods under the wings or a pilot of "non standard" mass by shifting the liquid around to compensate for the extra masses, this process should be performed whilst hovering on the ion columns shortly after take off. switches on the control panel allow the moving of liquid along the x,y and z axes and another switch can be used to set certain arrangements of liquid, to counterbalance certain masses, to an onboard memory. for example:
    upon takeoff from a supposedly uninhabited alien planet the pilot finds himself having to rescue an explorer who crash landed a while back. this explorer climbs into the fighter and rushes into the rear( yes this craft has a (tiny) living space for it's pilot on extended missions). now due to this "non standard" arrangement of mass the pilot must balance it to prevent tumbling/spinning when applying an engine burn. he starts the fighter's reactors and diverts the power to the ion columns on which he can hover, the fighter of course will hover at an unusual angle due to the changed centre of mass. the pilot then adjusts switches on the control panel to shift mass ( in the form of the dense liquid) in such a way that the centre of mass is restored to the point at which it should be, accelerometers and gyroscopes allow him to know when the centre of mass is restored to it's rightful position. once the liquid has been pumped into such an arrangement that the centre of mass is where it should be for using the main engines( this will be somewhere in the centre of the craft between the main engines), the accelerometers detect that the fighter is hovering in a level position and a light appears on the control panel. positioning is aided by a display of the fighter showing where the centre of mass is for the current configuration of liquid and other mass( the explorer), when this position lines up with the marker showing the necessary centre of mass the pilot knows he is ready to fly. the question is have the natives, who he was sure were not supposed to be on this planet, already opened fire?
    this neccessary centre of mass will need to be shifted to another marked( on the display) point when the boosters are used.
    i have included a diagram of the new control layout here
    Attachment not found.

    and a quick sketch of what the tanks would look like, tanks are in green connecting pipes and pumps are not shown( each tank will be subdivided by baffles to prevent sloshing)
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    Attachment not found.
    problem solved( isn't it)!
  • spacefighterspacefighter1 Posts: 0Member
    i think this model is just about finished now, any suggestions are welcome. if anyone thinks that there are any problems with the design please post on this thread. yes i know FTL travel is probably not possible and also that as this craft (ignoring the boosters) has an engine power of 4.8x10^17 Watts (2.4x10^17 watts from each engine) so will consume 776.7 kg of hydrogen fuel per second( calculated by dividing the total engine power by the amount of energy released by 1 kg of hydrogen fuel being used for the p+p+p+p-> He reaction) which is way more than it can hope to gather from space( density of interstellar space= 10^6 particles per cubic metre= around 10^-20 kg/m^3). anyway do you like the design, do you think it looks good you can download it as an skp(sketchup) file here the mk iii is also available here and here on my site.

    also see a 3d view here.Attachment not found.
  • spacefighterspacefighter1 Posts: 0Member
    i produced this image with blender, it shows a pair of Admiral Peck Class mk iv fighters flying across the surface of a highly volcanic planet, the fighter in the foreground is firing the gatling laser, the fighter in the distance is using the laser mounted in the turret. both are aiming at a target somewhere off the edge of the image. i think the glare effect looks good but perhaps not.Attachment not found.
  • spacefighterspacefighter1 Posts: 0Member
    i altered the rock texture and changed the glare effects.Attachment not found.
  • spacefighterspacefighter1 Posts: 0Member
    after admiral westwood gained control over the british space empire a squadron of freedom fighters using Hellhound mk iii fighters lead a raid against the alien ship that westwood is using to threaten the earth. the raid is partially successful resulting in the destruction of the massive ship's hyperspace drive however the ship is still armed and capable of causing severe damage to targets within the solar system. after the raid the surviving fighters, around half of the force that took part, flee into hyperspace. unable to realise what they are about to jump into some of the mk iii Hellhounds leave hyperspace at rendezvous point "D" , where a force of destroyers and mk iv fighters loyal to westwood is patrolling. to give the rest of his squadron a chance to escape the squadron leader draws the fire from his comrades by launching a suicidal charge at tone of the enemy destroyers, at the last moment he alters course to avoid striking the ship's hull and dives towards the planet corot-7b. he is pursued by two mk iv fighters...

    video will be posted soon
  • spacefighterspacefighter1 Posts: 0Member
    a first shot from the video...
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  • spacefighterspacefighter1 Posts: 0Member
    my video will be posted in the next few days once i have rendered it.
  • spacefighterspacefighter1 Posts: 0Member
    i am rendering as i type this, the video will be on youtube soon and i will post it on this thread.
  • spacefighterspacefighter1 Posts: 0Member
    after admiral westwood gained control over the british space empire a squadron of freedom fighters using Hellhound mk iii fighters lead a raid against the alien ship that westwood is using to threaten the earth. the raid is partially successful resulting in the destruction of the massive ship's hyperspace drive however the ship is still armed and capable of causing severe damage to targets within the solar system. after the raid the surviving fighters, around half of the force that took part, flee into hyperspace. unable to realise what they are about to jump into some of the mk iii Hellhounds leave hyperspace at rendezvous point "D" , where a force of destroyers and mk iv fighters loyal to westwood is patrolling. to give the rest of his squadron a chance to escape the squadron leader draws the fire from his comrades by launching a suicidal charge at tone of the enemy destroyers, at the last moment he alters course to avoid striking the ship's hull and dives towards the planet corot-7b. he is pursued by two mk iv fighters...

    i animated this with blender, sorry if it runs too quickly.

    i hope you like it, what do you think of it( fighter/animation).
  • spacefighterspacefighter1 Posts: 0Member
    sorry to post again but does no one like my animation?
    (and if someone posts some nice comments here i will send them ( by means i have yet to arrange) an "exclusive" obj/3ds file of a mk iii fighter(grey colour scheme))
    if this last bit counts as spam PM me and i will remove it.
  • L2KL2K0 Posts: 0Member
    camera too slopy, too confuse, too quick. hurts head.
    rent top gun, les chevaliers du ciel, iron eagle and the like, and copy the camera work.
  • spacefighterspacefighter1 Posts: 0Member
    L2K wrote: »
    camera too slopy, too confuse, too quick. hurts head.
    rent top gun, les chevaliers du ciel, iron eagle and the like, and copy the camera work.
    sorry,would it be better if the whole video was a little slower. i have some trouble rendering sometimes and with a slow computer like mine i have no means of seeing how fast the action runs before i render it. even preview renders take almost as long as the full quality ones i used here. i will look for these films and i have sen top gun already but that was a while back. other than the camera work which probably ruins the whole experience did you notice anything else. did anyone like the engine flame effects/explosions/laser effects/fighters?
  • Knight26Knight26189 Posts: 833Member
    So your proposal to solving the center of mass issue is to carry more mass, that takes up useful fuel volume, thereby limiting your range. Also you are probably going to have it be some super dense fluid, hence adding more mass. Your best bet, if you are unwilling to redesign the ship, is thrust vectoring, but not using the modern fighter engine feathers, you will burn them off to quickly. Best bet would be some some form of more solid vectoring plates, magnetic vectoring, or just bell nozzles. Yes this will have the result that when you light the boosters that your velocity vector points below the nose (most likely), but it would be far better then manual mass shifting.
  • L2KL2K0 Posts: 0Member
    i dont know. try using proxies while animating, then replace them with your detailled object for render.
    this will lighten your scenes, thus giving you better means to check you animation.
    cameras should move slightly. only then we'll understand what's happening, how fast is the plane, if it rolled, turned, climbed, etc
  • spacefighterspacefighter1 Posts: 0Member
    as this is a space craft the issue of range due to a lack of fuel carried is not an issue, the amount of fuel a spaceship carries determines how much it can change it's velocity by( it's delta V). also this craft is a bussard ramjet powered ship and although i have slightly exaggerated the performance figures( you would need ridiculously colossal scoops to suck in enough gas for the power this fighter's engines produce), this also means it does not have a fuel problem. in atmospheric flight the engines can remove what lighter elements can be found in the air and use as fusion fuel( if the planet has water vapour or methane in the atmosphere the hydrogen from these molecules can be used, the sheer temperature that the gas would reach as it entered should be enough to break the molecules apart.). i can see a loss of acceleration capabilities( including deceleration and cornering) due to the extra mass might occur but as the extra mass is unlikely to be more than 10%-15% of the original mass the loss of performance should be comparatively small. there are some nozzles on the engines that may be visible if you closely inspect my images but i thought that the mass shifting would be a simpler and more effective solution, when you say it is manual i would like to add that certain configurations of fluid for configurations of mass onboard the fighter can be preprogrammed into the ship's computers meaning that the pilot can shift between configurations he has preset at the touch of a button. the volume taken up by fluid tanks was not in use for anything when i first designed the fighter, it was just the space between the hull and structural parts/systems, so the loss of this space should not be too great a problem. thanks for posting.

    in response to L2K, perhaps that would help. the more i think about it the more i think i should render it again at a third of the speed it plays at in that clip. maybe this will make the events clearer even if it does make the action somewhat slower.
  • Knight26Knight26189 Posts: 833Member
    SF, I use the term range in a general sense here, as to how much fuel the craft can carry and still return to base after the mission. Relying entirely on ramscoops for fuel is a foolish idea, you will want to have an internal fuel supply should you be in a place where scooping is either not possible or impractical. Therefore, on a small fighter especially, you will want to dedicate as much internal volume as you can to fuel. Now, are the upper engines just boosters, or are they used continuously? If just boosters, then why not simply balance them, have one above, and one below, or two smaller ones below that match the thust output. IF all four run at once at all times, then cluster them with two mains instead. Go with the BAC lightning configuration with the engines stacked on top of each other instead of side to side.
  • spacefighterspacefighter1 Posts: 0Member
    ok, thanks for the advice but i think i have finished this model now. it is a bit unrealistic to derive all power from ramjets, perhaps there could be some tanks in the wings. the upper engines are boosters but they can run for up to 30 seconds at a time and work in a very similar way to the main ramjets, extra fuel for these would be a good idea but as i am very satisfied with this design now i do not really want to make many changes. i can see the sense in adding extra boosters but if they were fitted below they would prevent the craft from landing as the undercarriage only supports it a few centimetres above the ground. as far as i am concerned i think i have found solutions to most of the problems that would affect this fighter, after all the mass rearrangement would work even if it is not the most effective means to prevent spinning end over end when the boosters fire. in absolutely accurate reality the ramjets would not be very effective either without a scoop larger than the earth to collect enough hydrogen so if i have a design that can do this then it should not find itself in situations where collecting the hydrogen is not possible, the ram scoop systems are not vulnerable to enemy weapons fire nor do they interfere with the fighters maneuverability.
    i have posted a short animation of a tour around the mk iii version of this fighter( only difference is that the mk iv carries the gatling laser under the nose) which shows all the features of the design with this post. i hope you enjoy it, thanks.
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