Huge power loss when increasing angular velocity?

[rekimchuk13]

Hi all, could someone help me understand how increasing angular velocity with gears works?

I'm running into a weird issue. I have 16 windmills running. I tried to increase the output speed by 9 times. According to the mechanics, the output torque should become 9 times smaller, which is fine.

The problem is that as soon as I apply the 9x gear ratio(2 big gears), the input speed from the windmills themselves drops to about 1/5 or 1/6 of its original value. The initial torque from the windmills stays the same, but this drastic drop in speed means that 5-6 times the total power is simply vanishing from the system. I made sure the wind is not the problem by locking it at 150% on a single axis.

So, my question is: is it normal to have such a huge power loss just from trying to increase speed? Am I missing something about how torque and speed work in this system? (As an engineer, I can tell you it doesn't work this way in the real world, which is why I'm trying to figure this out)

[Professor Dragon]

Can you screenshot the bottom gear setup? Also the length of the axle below your bottom shaft. If I get time, I'll try and reproduce the setup.

Windmill mechanics probably ARE funky. I experienced substantial power drop off just by extending a shaft down a few rooms. You see different results by having a single large gear at the top of a shaft compared to the bottom, even though both should be equal. So don't expect real world behaviour. 
 

What is known here, specifically about losses from resistances is here:
https://wiki.vintagestory.at/Mechanical_power#Resistance,_Torque,_and_Speed

I think standard advice is you begin to max out at about six windmill blades before inefficiencies set in hard, so the setup you've got will be overkill in any case.

The other complication in the above setup is the different heights of the blades. 

I'm totally prepared to believe that you're seeing what you're seeing, and that the power output is weird. Most people just roll with it, but you could take this a bit further and put through a Suggestions post (or bug report if something is actually broken).

I also recommend these (admittedly older) videos to get an idea of in-game power behaviour:

Professor Dragon.

Edited September 7, 2025 by Professor Dragon

[rekimchuk13]

I decided to run some tests, and it turns out that everything works like in real life: the lower the sail speed, the higher the torque, and the higher the speed, the lower the torque. That's why they slow down.But in that case, I don't understand why in my other system, 72 windmills can't provide enough power to run 1 helve hammer at x9 speed (the gearing setup is the same as in the screenshot above).Through testing, I found that 1 windmill can sustain 1 helve hammer at 1/3 speed (even with 50% wind) using one large gear for speed reduction.This should mean that 3 windmills could run the same hammer at x1 speed (one gear for reduction, one for speed-up).Which means 9 windmills should run it at x3 speed (one reduction, two for speed-up).And 27 windmills should be enough for x9 speed (one reduction, three for speed-up).However, I have almost three times that many windmills (72), and the wind is at 150%. This should theoretically be enough for x27 speed (one reduction, four for speed-up), but for some reason, the system stalls even at x9 speed.

Edited September 7, 2025 by rekimchuk13

[rekimchuk13]

 

It's working in pulses. From what I understand, at high speeds, the hammer requires a massive amount of torque. To generate this torque, the windmills reduce their speed. Because the windmills have slowed down, the hammer also slows down, and now it doesn't need so much torque. This causes the windmills to speed back up, which in turn means the hammer requires high torque again. This definitely seems like some kind of bug

[Professor Dragon]

Wow. Kudos for testing.
I have nothing to add. 

Well, apart from the link to the bug tracker. It's worth making an account regardless of whether you decide to post.

Here is the front page link:
https://github.com/anegostudios/VintageStory-Issues/issues

And you can search for terms like "windmill" - I see that there are a bunch of issues logged already, so maybe your use case is covered by one of them (???).
https://github.com/anegostudios/VintageStory-Issues/issues?q=is%3Aissue state%3Aopen windmill

 

Professor Dragon.