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Space catapult

Discussion in 'Community Creations' started by Innoble, Oct 11, 2015.

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This last post in this thread was made more than 31 days old.
  1. Innoble Apprentice Engineer

    It's exactly as the title says: a catapult in space. I've been working on it for the last 4 days or so. It surprised me how effective it is.


    -Resource costs are negligible. Every shot is just a single warhead in terms of resources and the catapult itself is 60 blocks.

    -Accuracy is amazing, especially considering the way it works. I would not have imagined such a crude launching method to actually be effective.

    -Unlimited range. The warhead requires no power and its inertia carries it anywhere you want. The way I made it now, I think it loses 1 m in accuracy every 1 km. So effectively you miss by 1 large block every 2.5 km. That means that at 12.5 km, your accuracy is still better than the explosion range of the warhead. I strongly suspect I can improve the script to make it even better.

    -Can be used to target any place in the sky (360 degrees in all directions).

    -Can blow through whole asteroids in just a few shots. When planets come out, I am sure it can blow holes through those too.


    -I have not tested it, but I am pretty sure a gatling gun will ruin your day.The warhead moves pretty fast, but warheads only need 1 bullet to blow. Of course your enemy will probably blow more resources shooting the warhead, than you did making it, so it's still a win. Launch them on automatic (I think you can do 1 or 2 every minute) and eventually one will get through. Another option would be to just have more of these catapults firing. That will make sure some shots get through.

    -It's stationary. I doubt it could be effective as a ship (because of the rotors). On the other hand, since its range is virtually unlimited and can target anywhere... why would you need it to move? Also... any small ship with a large cargo container could carry the resources to build it. 60 blocks is not a whole lot...

    I'm not sharing the script and blueprint yet (I promise I will when it's done. Including a lengthy explanation of the script). The script is a mess at the moment and missing some features, like an autofire mode. I also want to make the shots even more accurate than they are now. Maybe also add an oxygen generator or something (it was annoying testing it on survival with no oxygen).

    If you guys have ideas about what else this thing should be able to do, let me know.

    EDIT: New video below. Also read my later posts if you're interested.

    Last edited: Oct 19, 2015
    • Like Like x 7
  2. Pennywise Apprentice Engineer

    You can try to launch not a single warhead, but a strut built of iron blocks with 2 warheads on its ends.
    If u add one more rotor on catapult end, which wil give a strut rotation in a plane normal to shooting trajectory, maybe it will add a chance to survive turrets fire.
  3. Delta99 Trainee Engineer

  4. Innoble Apprentice Engineer

    That's not a bad idea, but the execution has some problems. Another rotor fixed to a rotor will probably cause it to wobble, meaning it will lose a bit of accuracy (a lot at long range). You would have to place at least 10 blocks of iron between two warheads to prevent 1 warhead from detonating the other. Another problem is that the whole construction would need to be much larger to allow for welding such a large object. So it's possible, but I don't think it's practical. I would like it to remain cheap.

    I have been thinking about maybe making a heavily armored radar drone that can find targets for the catapult, communicate them while docking with it and protect the warhead in flight by flying in front of it. Yea that's a crazy thought, but I know it's possible.
  5. Bipin Trainee Engineer

    I could see this being used as some sort of mortar on planets, assuming the projectile would follow a ballistic trajectory. Nice work!
  6. Stiletto Apprentice Engineer

    Hahah! This is an awesome design with lots of fun possibilities. :D

    Once you work out all or most of the kinks, I can see things like a passenger seat with a rebelious scallywag engineer being manapulted into the deep confines of SPEEEESS!
  7. Innoble Apprentice Engineer

    That would be cool. I can't think of a better way to travel in style than with an unpowered cockpit launched by a catapult arm. Currently I only fine-tuned the thing to launch warheads, but if I could manage to put a formula in it for variable masses, you could launch anything really. As long as it is 1 block in size. It could even be used to transport cargo, provided you have a way to catch the cargo containers ;).

    I thought of another thing just now. Maybe I could modify it to use one arm, but 5 welders and grinders. Then the arm could keep rotating and picking up new warheads. Maybe launch one every 5 seconds. Imagine 12 bombs arriving at your base every minute. With some clever GPS manipulation (alternating a set of co├Ârdinates around a center co├Ârdinate) you could completely annihilate just about anything. I am also thinking about setting the countdown timer on the warheads so that it explodes on target, even when it doesn't hit anything. That's really hard though, because it requires you know the exact velocity of the bomb. I'm not sure if that is possible. But at least this way you can remove the warheads from the server when they miss, to reduce lag.

    In a week or so I will have plenty of time to work out this stuff.
  8. thatguywithahammer Apprentice Engineer

    I clicked "Space catapult" expecting to see a bucket on a stick flinging rocks or space balls across a square of green armor blocks. This was a pleasant surprise.
    Holy crap.
  9. AutoMcD Senior Engineer

    I'm amazed that the warhead does so much damage!
  10. Sarekh Senior Engineer

    That's a fun thing to see.. and quite the nice idea! I will mess around with it - expect frustrated reports of failure coming in ^^
  11. Innoble Apprentice Engineer

    New video. I solved the problem with turrets.

    Basically it goes like this.

    No defenses: Use warheads
    Light armor + turrets: Use heavy armor blocks (cheap and very effective)

    With heavy armor it's different. Small kinetic projectiles seem to disappear as soon as they come within 5 m. of the armor, almost as if bugged. This is probably intentional. Some blocks do not disappear, like cockpits, remote control blocks, grinders, cargo crates and floating items. Mass is a factor as well I think. In any case, below some treshold, you will do 0 damage with kinetic projectiles, even to any turrets that are outside of the armor. So even though my catapult can hit a turret accurately at 10 km with a heavy armor block, it will do no damage.

    When facing heavy armor and/or turrets, instead use what I did in the video below. The video also shows the amazing accuracy that is possible with the right script. As I said before, I will eventually share everything (workshop etc.), but it is not done yet.

    What I need to do next are:

    -A laser-antenna, remote controlled GPS spotter, so that I can sit inside my comfy catapult and fly the drone around to find targets. This needs a triangulation script, but that is not hard. I made one myself using turrets a couple months ago and I've seen an even more useful one that works at any distance. I'll manage this for sure.

    -More automation so that you can turn on the catapult and watch it empty its cargo shooting stuff. Right now you can do this, but for some reason it stops when you leave the catapult
    (you have to stay inside it). I think it has something to do with grid-updates and the landing gears. If you're not around, they seem to update less frequently. Not sure, but I need to work that out.

    -Options for selecting attack types. For example: I am thinking about making a script something that works like this. You make an ascii picture like:


    This is then turned into a GPS target list based around the center (T). It tells the catapult to fire at T and then fire 3 blocks to the left and 3 blocks to the right. You could make all sorts of weird pictures or even write your name in damaged armor. The coolest thing would be if you can take a drone, make a screenshot of the enemy base, turn it into an ascii picture, then feed it to the catapult. Anyways, this is probably too big a challenge, but who knows?
  12. estile606 Trainee Engineer

    few things:
    just curious, does making it out of interior walls do much for it? thinking of trying this out, but my computer has a crazy hatred of interior walls...
    what would happen if you fired a landing gear set to auto-lock? Ive been hearing that locking one at high speed can cause impressive explosions...
    would it be possible to measure the speed and distance of a target moving at a set speed in one direction, such as a cargo ship, and then automatically lead the target?
  13. Innoble Apprentice Engineer

    About interior walls: They are 3x lighter than light armor. That means the arm speeds up faster. They also require less resources to build (though the buildtime is longer). The arm would also have to be longer if made out of light armor blocks. Basically the "average" distance of mass to the rotation center needs to be at least 13 blocks. That means 26 blocks long if the blocks have a uniform mass distribution. Fortunately the landing gear is very heavy and sits at the end. That's why I get away with 18 blocks. With light armor it would probably be 20 blocks or so. That is if you want to reach max velocity for your projectiles. Perhaps you can download a mod that gives different graphics to the interior walls.

    I did try the landing gear set to auto-lock. Sometimes it worked, sometimes it didn't and when it didn't, it was bad. With very long arms, or slightly below max rpm (25 rpm or so), it seemed the most stable. You're probably asking because you would like a catapult that keeps rotating and picks stuff up as it passes by. I tried this and it didn't work for me. Many things did not work. I tried many configurations (double arms, rotating wheels, very large arms with 5 landing gears on it).

    At one point I had a beautiful solution with 4 crossed arms (like a "+") on both sides. It could load 8 warheads and then fire them all in 2 seconds, a quarter of a second apart. I had it fully scripted too. Then I found out that the warheads inherit the velocity of the entire grid they're connected to, not just the endpoints. A rotating "+" has net velocity 0, so they flew off with 0 velocity. You would expect them to get the velocity of the endpoint of one of the "+" arms but that's not how the game works. I tried to solve it by connecting each "+" arm with a piston so it becomes its own grid. That would work, but when adding the third piston, the thing started shaking like mad and exploded. It is definitely best to keep the number of grids low. My current setup has 4 grids (small base, big frame, projector grid and rotating arm). This is the absolute minimum required to make it work.

    Another thing about landing gears. If you look at the video, you can see I use two landing gears. One to temporarily lock the projectile in place and another on the arm to pick it up later. While grinding the block that connects the projectile to the projector, the projectile needs to be kept in place (or it jiggles around like mad). You might think it is possible to use the landing gear of the arm for that, but it's not.

    The problem is this:

    The arm is connected to the projectile, the projectile is connected to the projector grid, the projector grid is connected to the main catapult frame and the main frame is connected to the arm.

    This creates some sort of instability loop and blows the whole catapult apart VERY violently. This is why I added the second landing gear which is connected directly to the main frame. Even with that setup, you need to disconnect one landing gear before connecting another. I give that a full second, because landing gears don't always update correctly (you see them jump around in your terminal menu).

    As for your last question. I did think about this. Assuming a target is travelling at constant velocity and you have a good spotter (preferably turret triangulated)
    you could certainly find two gps coordinates with timestamps and project a path. However, I think the firing angles (base rotor and arm rotor) of the catapult can't be solved analytically in
    this situation. As soon as you change the angle a bit, you also change the rotation time, which changes the target location (it moves), which changes the angle, etc.
    You would need a numerical algorithm to find the correct angles. Even if we could use the computing power required, I think it would just be too hard.
    Remember that with velocities of 104 m/s, 1 simulation step means 1/60th of 104 m, so almost 2m. error. Add this to the error that comes from the 30 s. delay between spotting an enemy and
    firing the catapult and you can see how this would be difficult. Any small error in spotting the enemy will be magnified greatly in those 30 seconds.

    The setup is amazing for assaulting stationary positions (unsurpassed in my opinion), but I doubt it will ever be useful for moving targets.
  14. VilniusNastavnik Apprentice Engineer

    Soo basically only useful against stationary objects. Be interested to see if you could make it some how lead a moving target and hit it from that range.
  15. Sinbad Senior Engineer

    this, and a few more like it, would make very good decoy launchers. throw out a wave of ten blocks, 8 are decoys, half a second later: warheads.
  16. Innoble Apprentice Engineer

    That's very achievable actually. The catapult is still only 65 blocks big so very cheap to build. Not sure if the server will like 10 of them firing at once, but sure, you can do this. I like the stone crates because stone is (normally) always so useless. With this, you can hoard stone in your base and use it when you come upon a pirate base or something. Maybe anchor it on a small asteroid and mine that when you need ammo (just be aware of the limiting field of view, maybe you would need 2 catapults then, 1 on both sides).

    Also, as for using this only on stationary targets: Even ships don't move all the time, especially with dampeners. Remember that even at 20 km distance, if you spot a ship and it hasn't moved a few minutes, you can launch something at it. I think most large ships actually sit still all the time, being "mobile" bases. Those are perfect targets as well. The only thing this catapult is not suited for is small ships like fighters, miners, etc unless they are parked (which happens). Remember that if you do it right, they will never even know you're coming. You use an unmanned drone outside turret range for target acquisition. All the enemy knows is that suddenly something is tearing through his ship, completely ripping it apart. That will be the first sign.

    Maybe I will try to make a version that can attempt to hit a moving target, but it would have to have a 100% constant velocity, which is very limiting. The trick would be to transmit the target information at the time the arm is already rotating. Maybe you need to rotate the arm continously, just waiting for a target. Even, then think about how easy it is to avoid gatling bullets at max range (800m). Gatling rounds move a lot faster than 104.4 m/s and that's only at 800 m. If you only sneezed in space you'd drift far enough to avoid getting hit by the catapult at long range. Of course the helmet will conserve your snot's inertia and keep you stationary... but you get the point. If it were possible though, it'd be quite cool if a catapult could hit a cargo ship though. They move 100% constant.
  17. Hiramas Apprentice Engineer

    Amazing work, but I'd really like to see how many catapults would be needed to get through the green bases defenses...

    edit: I wrote that before seeing the second Video, WOW!
  18. estile606 Trainee Engineer

    actually, what I meant was using a landing gear as the projectile, and attempting to make it explode on purpose.
  19. Innoble Apprentice Engineer

    Seems difficult. Large ship landing gears are pretty unwieldy objects to throw. You'd need a specifically set up catapult for it, that allows room for it. Mine is only really able to throw 1 block objects, with a few exceptions (like grinders, drills, etc). It could be adapted of course.

    The landing gear would need to arrive at exactly the right angle to lock the target and I am not sure if the autolock will still be on after you disconnect it from your own grid (with the grinder). They don't seem to need power, but often my landing gears unlock when i disconnect them from the grid. Also, the reason landing gears explode so violently might be because they are attached to a heavy object with a high inertia. On their own they might not do the same. There's a good chance it will only serve as an oddly shaped heavy projectile.
  20. Clunas Junior Engineer

    Have you tried this with a modded top speed?

    Regardless, this is amazing!
  21. Innoble Apprentice Engineer

    I never try to use mods, because it means that if I share what I make, it will not work for everyone (unless they also install mods). I tend to only use mods after a game is completely finished and patched. This game is changing too fast for now. I do like to check out the mods people make in video's though. It shows what this game is capable of.

    Anyways, for now the catapult is busted. If i start it after the last patch it will explode or crash my game as soon as the landing gear locks. It is a consequence of the "rotor stability improvements" I believe. Anyways, I am sure I will be able to make it work in the future, maybe with some adjustments or if Keen patches the rotors/landing gears again.
  22. Clunas Junior Engineer

    Ah, that's quite unfortunate to hear! I hope you'll be able to resurrect it one day
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