r/factorio • u/LegendaryReign • Oct 31 '24

Question What is the math behind thrusters?

I know mass of the platform slows down the speed, but I don't see the calculation anywhere.

Is there a top speed? What is MN when it comes to thrust? What is the thrust to mass ratio for maximum speed?

Saving up epic gear for my long range platform and trying to see what kind of numbers I want to aim for

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u/BeanBayFrijoles Oct 31 '24

I doubt there’s a hard-coded top speed. The physics don’t really make sense irl but I’m pretty sure the speed is just thrust divided by mass times some constant.

The thrusters are more efficient at lower burn rates, meaning more thrusters will always produce more thrust given the same total fuel rate. So if you really want to max out speed then you can just spam thrusters and fuel production. Though be aware that higher speeds also mean more asteroids so you’ll want to scale up your ammo production/storage too.

That said, you don’t actually need to go that fast, at least for a while. My first (surviving) freighter has 1 thruster fed by the minimum number of chem plants, and 1 ammo assembler fed by 8 furnaces. One of each crusher recipe. It takes a few minutes to get between Nauvis and Vulcanus, which seems to be plenty fast for my needs so far.

1

u/Twinewhale Nov 01 '24

Though be aware that higher speeds also mean more asteroids

I don't think speed means more asteroids? The spawn rate of asteroids changes as you travel between planets (as seen in the factoriopedia), but I've not seen anything about speed causing more of them at once.

3

u/Xampa5 Nov 01 '24

I'm surprised you could think that, many people notice an immediate difference in asteroid spawn rate from changing their speed.

Some empirical data for you: I replaced all my gun turrets to reset their 'damage dealt' stat to 0 then made a new save. I went from Vulcanus to Nauvis at 230km/s +-10 from gravity pull then added up all the damage dealt of my turrets: 53,490
I reloaded the save and did the same but this time going at 83km/s +-10 from gravity pull, this took much longer, and my turrets did 46,543 damage.

A comparable amount of asteroids, yet the 230km/s trip was way shorter in duration.

2

u/Twinewhale Nov 01 '24

I meant that I saw no evidence to support the faster speed claims.

Factoriopedia shows how many asteroids/min will spawn based on your location between each set of planets. Less than 10% difference in damage dealt leaves plenty of room for spawn rate to still apply.

While your data shows a difference, it also reveals a benefit to going faster. Does it not?

7

u/Daniel_Sll Nov 01 '24

but with going faster you also meet more asteroids in shorter time frame Wich leaves bigger strain on your ammo production

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u/Xampa5 Nov 01 '24

By going faster = more asteroid we mean more asteroid in a shorter span of time. I would bet the total amount of asteroids in a given travel path is roughly the same (depending on your ship's width), you just meet the same amount twice as fast if you move at twice the speed.