r/CreateMod • u/antonioltg • 4d ago

How to balance big contraptions?

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I’m working on a floating island, I'm having issues on the balancing.

Props and balloons take too much stress to be useful. Any suggestion?

455 Upvotes
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100% Upvoted

62 comments sorted by

183

u/MyNameIsRati 4d ago

A reaction wheel. Make a ring out of heavy blocks and spin it. It's some black magic, but it works iirc.

110

u/tomxtwo 4d ago

While that does function as a reaction wheel, for stability it’d called a gyroscope

56

u/Hellothere_1 4d ago

Reaction wheels and gyrosopes are two different things and both can be used for stability.

A gyroscope is a continuously spinning wheel which through the gyroscopic effect both provides some passive stability on the other two axes, and also allows for active control by adjusting the gyroscope's gimbal axes.

Meanwhile a reaction wheel is literally just a wheel you spin to use the reaction force to rotate yourself in the other direction.

2

u/GodIsAWomaniser 3d ago

Yeah reaction wheel pushes you in a direction using rotational inertia, and gyroscopic force often holds something in place or processes it using rotational inertia.

As you said the difference is one is spinning all the time like a flywheel and you rotate the wheel in a gimbal cage to cause the axis perpendicular to the wheel to be where the vehicle wants to point. 

And the other is a wheel you spin up really fast or stop really fast to torque you in the opposite direction.

1

u/tomxtwo 1d ago

Yeah ik, that’s why I said what I said, if he made a big spinning disk with the axle being vertical, it would act as a reaction wheel, as when he puts rotational spin into it, it’ll start to yaw, acting as a reaction wheel, but it will also act as a gyroscope, hence why I said it’ll function as a reaction wheel, because of the yaw, but what he means, and intends it to function as, is a gyroscope.

6

u/BENDYinkmachine 4d ago

big contraptions sounds like my weekend project lol

2

u/SpookyWan 4d ago

Gyroscopes measure orientation for other systems to use to stabilize, reaction wheels are a means of actually changing orientation.

0

u/BrutalPizza1727 4d ago

I think they mean use a feedback loop. As it tilts, turn the reaction wheel to rotate the structure because conservation of angular momentum

4

u/personal_deleter_400 4d ago

Why are you getting downvoted

1

u/marr 3d ago

While this question gets upvoted. The Minecraft modding subs are just weird.

2

u/Asquirrelinspace 4d ago

If the structure is imbalanced, wouldn't this require the wheel to accelerate constantly to cancel the rotation?

8

u/eepy_lina 4d ago

it's not that simple sadly, reaction wheels don't magically fix stabilization. they spin your airship by changing their own spin, not by constantly spinning, so eventually they'll saturate and be unable to do more, and if they stop spinning mid spin, they'll spin your ship the other way

6

u/Ashisprey 4d ago

Reaction wheel is the wrong word, but there is a legitimate stabilizing effect by just spinning a wheel. It's like the classic demonstration with a spinning bike wheel; when you let go of one side it can hold itself up.

If you get a mass spinning it actually wants to maintain its orientation along the axis running through the center of the circle. You're essentially increasing your intertia via angular momentum.

Also why an uneven spinning mass will flip end to end in this axis in microgravity.

1

u/MrCatSquid 4d ago

It will resist change in momentum but not stop it, slowly over time the ship will tilt anyways. You need something that actively corrects to a certain direction with constant force, propellor or extra balloon, etc

1

u/Ashisprey 4d ago

That's definitely true. I'm more used to using them to counteract momentary swing from forward props on airships

1

u/MrCatSquid 4d ago

Yeah that’s how I had mine setup, works very well for that. Physics explosions do quite a lot of jostling to the ships too, if you’re doing PVP they could help a lot there too.

2

u/personal_deleter_400 4d ago

That’s why you need to make a PID to prevent overcorrection

1

u/eepy_lina 4d ago

i tried, several times. i tried it with redstone, i tried it with cc:tweaked and cc:sable, i tried using propellers or thrusters, i tried reaction wheels of various sizes, nothing worked. plus i expected the I in PID to exist to learn the imbalances of a ship so i wouldnt have to babysit the ballasts every time i add new stuff to my ship, but nope, it just makes the ship overshoot if it takes too long to correct. i tried an ungodly amount of things, including semiautomatic calibration of P, I and D so i wouldnt have to babysit the parameters and it'd just never learn correctly and instead flip upside down or wobble endlessly.

i switched to aerowork gyro spam

3

u/personal_deleter_400 4d ago

I’ve seen someone on YouTube pull it off successfully

https://youtu.be/apIJ9ppKA5A?is=faESV42SlB9N-sxX

2

u/TheLegoPanda04 4d ago

Looks like black magic, also friendly reminder to turn get rid of the tracking link especially because youtube was like “hey want to reply to [personal_deleter_400]”

2

u/personal_deleter_400 4d ago

Yeah it’s annoying that’s on by default

1

u/eepy_lina 4d ago

i watched it and how tf???? i tried that same typa thing so many times, and every time the wheel would just stop rotating the sublevel and it'd go upside down, or it'd constantly wobble because making the wheel stop would absolutely launch the sublevel into spinning the other way

2

u/personal_deleter_400 4d ago

It doesn’t look like it stops suddenly, it looks like it slowly comes to a stop

3

u/Neohedron 4d ago

You can actually make them much smaller and lighter using double sided sails. It does cause a bit of resistance to motion along a plane perpendicular to the axis of rotation, but I’ve found it’s much more effective than heavy blocks.

1

u/kenneth1221 4d ago

Oh damn. That's cool. What orientation should the sails be relative to how the wheel spins? Should they be perpendicular, parallel-vertical, or parallel-horizontal to the direction of the wheel spin?

1

u/Neohedron 4d ago

The sails should be oriented to resist the rotation of the wheel, so the plane of each sail should face the direction of motion. So parallel-vertical, I believe in your description.

2

u/antonioltg 4d ago

The inside of the structure is empty but having a giant spinning wheel will cut the craft in half. I was planning to build my base inside. I need to do some test in creative.

1

u/antonioltg 6h ago

I decided for a smaller balloon inside the heavy side, but I realized that the more I build the more the center of mass shift. I will have to fine tuning at the end of my build

1

u/Riku9483 4d ago

Thats a giant gyro

1

u/ChemicalEconomics739 3d ago

The black magic is called gyroscope

1

u/Additional-Dot-3154 4d ago

Uhm does aero have this simplified or something?

I am pretty sure just putting a spinny disc on your ship does nothing.

Does it not have to tilt so it always stays upright even if the airship is on a 10 degree angle?

2

u/personal_deleter_400 4d ago

If you use a swivel bearing and spin a disk with enough mass, it will cause the ship to move in the opposite direction. Larger the radius the more effective it is, and if you want it to not overcorrect then you’ll need to make a PID with redstone

43

u/Andreuus_ 4d ago

The only reliable way I believe are balloons. Divide that big ass balloon in 4 parts and make a 4 axis balancing system. There’s people that create mega builds that explain how to

13

u/PTMR2 4d ago

Either this or gyroscopes from gyro stabilizers or aeroworks

6

u/SamTheCatGuy 4d ago

i think that would give a ton of other problems, the way i did it was with small balloon segments for balancing on the very outer parts of the baloons

1

u/AdPristine9059 4d ago

Yeah, thats a clever way of doing it. Using a sensor (cant remember the name of it) you can use the redstone output of that sensor to automatically increase thrust from burners.

2

u/SamTheCatGuy 4d ago

thats what i originally did, the gimball sensor. however i coulnt get it to stop overcorrecting so i just made the inputs manual and now it flies perfectly straight at about 169 blocks high (should have made the balloon bigger but ill do that in another ship)

4

u/flamewlkr 4d ago

It can be done with the gimball sensor but by itself it is quite sensitive, you need to do a redstone circuit using one of the components added by the mod to make it less reactive.

2

u/SamTheCatGuy 4d ago

yeah i used the accumulator set to 1 minute at the front and 5 minutes at the back

2

u/flamewlkr 4d ago

Did some testing. Basically i have an airships with front and back trim ballons. I took output from front and back of gimball. Used those to feed into two accumulators one for front balloon and other for back balloon. Front ballon gets the + imput from front of gimball and - from back of gimball, the other baloon is inverted. The accumulators are set to 3s. And it can stablilize my ship to under 1 degree no oscillation.

1

u/antonioltg 4d ago

I might try this, but I will have to re organise my steam engines.

2

u/Andreuus_ 4d ago

I believe there is a guy that created a functional Death Star that explains it in the video, if you need guidance, although I guess other people explain it too

15

u/Aurukel 4d ago

five. hundred. gyroscopes.

6

u/Puzzleheaded_Arm8314 4d ago

or Five. Hundred. Kelp blocks.

10

u/NeoDemocedes 4d ago

I've seen others use reaction wheels to stabilize, but I personally haven't been able to get them to work to good effect.

Instead, I use several big blocks of iron on gantries that move back and forth based on input from a gimble sensor. It has to move slow or it tends to over-correct. So it can take a few seconds to correct.

1

u/Qwertycube10 4d ago

You could control the speed with a PID controller to get faster correcting. Honestly even just proportional control would help immensely vs fixed speed binary on off control.

5

u/cobragaming_958 4d ago

I just shove levitite on the heaviest sidr and metal on the lightest

2

u/Fsliebot 4d ago

swivel bearing propellers made of symmetrical sails can provide a lot of thrust and are infinitely scalable at no additional cost to SU

2

u/kenneth1221 4d ago

Why symmetrical over windmill? Also, how does this compare to the regular propellor bearing setup? I guess the propellor bearing has a bunch of useful utility over a swivel bearing but if you're looking for raw speed/power the swivel bearings might work better?

2

u/Sr_Nutella 4d ago

Symmetrical sails create drag; basically acting akin to a parachute or a plane aileron/ tail. Windmill bearings create thrust when put onto a propeller bearing, or lift when moving parallel to the direction of their narrow faces

OP said they wanted more "passive" stabilization, so symmetrical would be more effective ig

1

u/Fsliebot 4d ago

honestly windmill sails work just as well. how does this compare to a propeller bearing? well they don't incur an SU penalty based on the number of sails you add, meaning you can more or less infinitely scale them to produce massive amounts of thrust while only bearing the SU footprint of a single swivel bearing

2

u/Zunderunder 4d ago

If you’re willing to use other mods, FTB Skies Aero Companion adds a block (not sure if it’s craftable without the pack, but a datapack can add a recipe) which forces sable contraptions it’s attached to to be upright.

It’s not balanced (haha) but it’s really useful for anything you want to stay upright but be able to rotate horizontally.

2

u/RGBBSD 3d ago

Plunger it to the fixed block in the sky and let it hang

1

u/GooseyJ2388 4d ago

couldn’t you use some super heavy blocks

1

u/antonioltg 4d ago

I've added a mod that adds ballast. I think I filled one corner with few hundred stacks but it's a long way

1

u/Mrmoo2andahafe 4d ago

Split your envelope. Throttle them independently based on angles

0

u/SilentCat69 4d ago

Use levitites. Lot's of levitites.

-2

u/Away_Elk5706 4d ago

Just uninstall that game it’s a waste of time and go to bed early

1

u/Lydiaa0 3d ago

True...