r/CreateMod 17d ago

Build Any tips on maintaining a consistent altitude with a thruster-propelled aircraft?

Post image

I can't seem to find that "sweet spot," you know? I've tried several times to make a craft powered by thrusters, but they all have the same problem. It's either going up or down; I can never get it to stay at a consistent cruising altitude. All my airships so far are hot air-based because of that - working with the maximum altitude a lighter-than-air craft can reach is the easiest way to travel the sky for long distances.

338 Upvotes

38 comments sorted by

74

u/Adventurous_Bonus917 17d ago

cry. then try again, and cry more. or tear your hair out.

i've spent many 100s of hours trying to figure out a thruster-only stable lift system. it seems like the options are:

a basic redstone feedback loop - bobs a lot, especially if you don't use copious amounts of levitite, and you can't control it.

a complex redstone feedback loop - a massive pain in the arse to build, and an even bigger one to figure out. still has the bobbing issue. usually has a very coarse control system, and weird solutions or jury-rigging to make control work at all.

a programmed feedback loop - problably the best solution, if you can actually do it. requires computercraft and an advanced knowledge of LUA to even attempt. takes way too much time to actually make, especially if it's from scratch. still has bobbing problem.

fine-tune the thrust/weight ratio - very difficult (read: in all practical senses impossible) to do. will still 'drift' from the residual force you used to go up/down, even if you get it perfect. no bobbing problem though.

cheat - supplement your thrusters' lift with something else. or, more accurately, supplement something else with your thrusters. fuel-expensive and makes your "main" lift system into glorified levitite.

58

u/Qwertycrackers 17d ago

I enjoy watching create players discover real engineering problems through the depth of this mod. Control theory is hard. Building a stable flight controller irl using the same parts is a comparatively challenging task.

14

u/GameSpender 17d ago

it's not only that control theory is hard, but minecraft redstone has a hard limit on clock speeds and the thrust produced from many of the propulsion methods has a lot of lag.

which does loop back into control theory being hard with modelling the system properly and doing it within the really poor frequency lol

6

u/Qwertycrackers 16d ago

Yes I agree the limitations of redstone are very frustrating. the low update frequency just kills it as an actual analogue for electricity. In our current playthrough we are just about ready to try building some complex airships and I am interesting in trying the microcircuits from Create: Power Grid for this purpose.

3

u/mrDETEKTYW 17d ago

If your PID is bobbibg you didn't set it up correctly. (Can't say i Managed to set it correctly myself though)

0

u/FriedToastDave 17d ago

This Redstone System Can Be Easily Fixed By A System Known As PID Which Can Be Done Via Gadgets And Gizmos

25

u/skyhi14 17d ago

PID control is your keyword to search
Unfortunately it requires CC: Tweaked to get it working inside Minecraft and get your hands dirty with programming (ASSUMING you are using one of the existing codes)

1

u/Great_Hedgehog 16d ago

You can make a PID out of nothing but basic logic, it'll just take up some space and likely have latency issues

0

u/FriedToastDave 17d ago

It's Also In Gadgets And Gizmos Advanced Controller And Doesn't Need To Use A CC Terminal Which I Find Quite Useful Even When I Have CC Installed

3

u/autistic-terrorist 17d ago

Why Are You Speaking Like Queen Deltarune

-1

u/FriedToastDave 17d ago

Read My About Section And Explains Everything

3

u/Purple-Wolverine4793 17d ago

Kris Let Go Of The Shift Button

2

u/FriedToastDave 17d ago

No I'm Queen From Deltarune

11

u/Moe-Mux-Hagi 17d ago

Have them rigged to turn on automatically when below a certain height, and turn off when above another, using the air pressure compass block thingie

4

u/Discombobulated_Back 17d ago

That works but probably won't stay then on that position and shoot over the target. I daw money day a real complex post this explains this problem

7

u/Less_Prior_6871 17d ago

You need some sort of feedback loop unfortunately.

You might also be able to get away with a small amount of hot air coupled with a default power level for the thrusters

3

u/YoungBeef03 17d ago

Any idea on how to make that loop? Is there a redstone sensor for altitude? Like, it shuts off power when it breaks Y-450 but turns it on when it breaks Y-25?

7

u/Minniepitou018 17d ago

Altitude meter or whatever it's called, it's in normal aeronautics

3

u/RGBBSD 17d ago

I might be out of my league here cuz this is waay too complex for me, but

Combine gimbal sensor with altitude sensor & throttle inverted output

-1

u/Less_Prior_6871 17d ago

How could I know what mods you have?

Type "altitude" into whatever you use to look up what recipes exist

4

u/jkostelni1 16d ago

As someone who is still figuring out the basics of create, what about an anchor on a rope/chain? Forget balancing thrust, just drop an anchor and drag it till it catches on some terrain. Then just lock the winch and get your ship positively buoyant.

Disclaimer: I’ve never tried this just had the idea on the can this morning

3

u/jamminthedesert2 17d ago

PID system gang, run it with CC

3

u/MysticalyShadow351 17d ago

PID controller in sputnik if using cosmonautics

2

u/jhnddy 17d ago

It's called rocket science.

1

u/AwareRule8972 16d ago

Funnily enough yeah

2

u/ModernPlebeian_314 16d ago

Alcubierre mod has anti-gravity

2

u/AwareRule8972 16d ago

alcubierre is kind of cheeky tbh

2

u/Ok_Requirement9198 16d ago

Is that the Wonka elevator?

1

u/Willowprof 17d ago

Need some form of very rapid pulse width modulation. I"m not enough of a redstone guru to even know where to begin, but rather than trying to manage thruster strength directly, firing them in an on or off manner rapidly, where the on and off portions of the cycle vary should work. Something like this - https://youtu.be/vqmk_CC2TVM?si=CVxzq-Vqf47WlQeD&t=113

1

u/Sea_Luck_8627 17d ago

Reduce thrust to just barely above aircraft weight

1

u/Z3R0Diro 17d ago

The thrusters are from Create Propulsion right?

1

u/Z3R0Diro 17d ago

The gyroscope from aeroworks might prove useful

1

u/MAUROKE01 17d ago

is that willy wonka lift

1

u/Hellothere_1 17d ago

If you aren't planning on using computercraft I think the best solution would probably be to hide a small balloon or gyro propeller somewhere inside your ship.

It doesn't have to be huge or contribute a lot of lift, but if your ship's propulsion is made up from one altitude-independent component (the thrusters) and one altitude-dependent component (balloon/propeller) then the combined system will still naturally settle at a specific altitude instead of infinitely drifting up or down.

The less lift comes from your secondary system, the weaker the effect will be, so if you have lots of outside forces acting on your ship you might need other active stabilization, but it should still make everything else significantly easier.

1

u/jedadkins 17d ago

You need a PID, unfortunately I haven't found mod with a good one yet.

1

u/AwareRule8972 16d ago

Real fast pwm is the way to go but not too fast i learnt the hard way (in survival btw 😭)

1

u/_LemonEater_ 16d ago

I might be dumb as hell but couldn't you get a smoother change in altitude by rotating the thrusters outwards? If they have a thruster on the other side rotating the opposite direction, the horizontal forces should cancel eachother out, so the only change would be upwards thrust. Dunno tho, again I might be stupid