Simple automation for mechanical filters: pump only when it's not full

[avc15]

Hey everyone,

Some people consider mechanical filters exploitive and for some it's just a logical use of parts available in the game. But there's a problem to solve with them - when your output line is full, the pump keeps running into your exhaust line and wastes power! So I want to share one simple solution for that problem.

Here I have a very simple gas pump feeding a pair of exosuit docks. This is one of two access points to my magma biome. (I tend to put exosuits in places far from my base, not in large banks right outside the base doors)

The other pump (on the bottom) is just for a pumped airlock, I know this is not a popular airlock design but I prefer it to more common alternatives. Yeah even this can be improved to reduce power usage, I have been lazy because it usually doesn't get much traffic.

Here's a basic breakdown of the air system. I find that the automation is a bit more stable with the extra gas valve in-line with the pump, set to 999 g/s, but you don't really need it.

And now here's what I do to make the pump stop when the docks don't need anymore air. There are a lot of other ways to do the same thing! This one just happens to be really easy to put together & doesn't really have many ways you could break its logic.

(if you use a "gas filter" - the building provided by the game - you don't have this problem, the pipes block and the pump stops)

Look how simple. So all I have are two gas element sensors, one past the halfway point of my supply line, and one at the VERY beginning of my exhaust line. Both are set to sense Oxygen (the gas I'm filtering).

When the supply line empties out, we get a "set" signal and the pump turns on.

When the supply line is full again, a packet of oxygen will go through the exhaust and we get a "reset" signal. The pump shuts off, and only 3-4 packets of oxygen overflow.

You can also use this same approach for other interesting things. To sense when your gas or liquid reservoirs are full. To keep only a small amount of hot water sitting in the supply pipes for your electrolyzers. You name it

Feel free to share your other designs for this same purpose, I know there are many ways to do it.

[biopon]

I think the mech filters are devilishly clever, but a bit cumbersome to set up. I prefer the slightly larger shutoff+sensor filters instead. These also don't use any power, and may even be easier on the game in terms of performance. They also work fine with full packets and completely avoid the overflow problem you describe.

For the avoidance of doubt, this is what I'm talking about:

https://www.reddit.com/r/Oxygennotincluded/comments/984pt9/robust_pipe_filter_or_how_i_learned_to_love_loops/

[avc15]

I've seen that design, it seems pretty nifty! But I have one question about it.... can it reliably send each packet of water down output A, and everything else down output B, without ever getting the wrong packet in the wrong output?

I will have to experiment some with it.

[Mullematsch]

3 minutes ago, avc15 said:

I've seen that design, it seems pretty nifty! But I have one question about it.... can it reliably send each packet of water down output A, and everything else down output B, without ever getting the wrong packet in the wrong output?

I will have to experiment some with it.

Yes. Never had any issues with it no matter what game speed, saving etc.. 

Only thing is if you do not include the loop and an output backs up, the filtering breaks. But that is just how the shutoffs work so include the loop and it should work reliably. 

EDIT: This will reliably sort for example water and oil. The way you worded it, I guess you might just want to sort out one liquid and send the rest to the other output. This can also be achieved using just one shutoff. Again you will have to include the loop or it will break if backed up. 

[biopon]

53 minutes ago, Mullematsch said:

This can also be achieved using just one shutoff.

Not reliably. Stuff can process in the loop past shutoff A because:

1) The shutoff is closed, because it's the wrong element

2) The shutoff is open but backed up

You need 2 shutoffs and 2 sensors. If you want, say, "oil" in A and "everything but oil" in B, you can just use a sensor set to oil for B as well, and then wire it with a NOT gate to its shutoff.

The cool thing about this design is that you can keep adding sensors and shutoffs for different elements. When I get to pumping up the loose crude from the oil biome, I set up one big filter loop that also has water, pwater, petroleum. Once you do this there's no "everything else" option, so unless you account for all possibilities with a sensor+shutoff pair, you're going to eventually get something in the loop blocking it.

[Mullematsch]

1 hour ago, biopon said:

Not reliably. Stuff can process in the loop past shutoff A because:

1) The shutoff is closed, because it's the wrong element

2) The shutoff is open but backed up

You need 2 shutoffs and 2 sensors. If you want, say, "oil" in A and "everything but oil" in B, you can just use a sensor set to oil for B as well, and then wire it with a NOT gate to its shutoff.

The cool thing about this design is that you can keep adding sensors and shutoffs for different elements. When I get to pumping up the loose crude from the oil biome, I set up one big filter loop that also has water, pwater, petroleum. Once you do this there's no "everything else" option, so unless you account for all possibilities with a sensor+shutoff pair, you're going to eventually get something in the loop blocking it.

Yeah, you are right. 

I love the sensor + shutoff combination, used it to build a liquid & gas sorting system in my last world. 

 

[Miravlix]

I thought the "exploit" is that the filter doesn't use power at the moment?

 

My mFilter setup is a loop that the feeder adds to if there is room, so the packets loop around until there is room to export, so it can never block in a harmful way. This always require either a dedicated exit for the every type or a "not" exit.

[Denisetwin]

On ‎2‎/‎16‎/‎2019 at 10:10 PM, biopon said:

I think the mech filters are devilishly clever, but a bit cumbersome to set up. I prefer the slightly larger shutoff+sensor filters instead. These also don't use any power,

Has something changed, don't liquid shut offs use 10w each for power?  I just checked the Wiki and it still says that too.

 

[beowulf2010]

28 minutes ago, Denisetwin said:

Has something changed, don't liquid shut offs use 10w each for power?  I just checked the Wiki and it still says that too.

 

For whatever reason, they claim to need power, don't work if not plugged in, but either don't actually draw power or use power for such a small fraction of time that it's immeasurable.