0.13 station unloading

[vanatteveldt]

With thanks to @siggyboy's comment in viewtopic.php?f=18&t=29961, I had some fun designing a new unloading station for 0.13.

Apparently, 4 stack inserters saturate a blue belt, so optimal throughput would be 2 wagons -> 12 inserters -> 3 belts, and there are some good designs around for that, e.g. https://imgur.com/3bQ5Oi1. However, I really don't like 3 or 6 belts as they are hard to balance or reduce, so I wanted to design an unloader that unloads to 2 belts per 2 wagons. Combining the basic inserter layout linked above and the 3->2 balancer from http://i.imgur.com/6zAJKdu.png?1, I designed the following:



(Obviously, to be upgraded to blue belts later)

And in action in a 4 wagon iron unloading station:



(which of course still requires a 4-to-n balancer to even out the output from both wagon pairs)

I think it should be a good balancer, but this is my first attempt so any comments/feedback/critique welcome!

[MrDrummer]

What is the point in the underground belts in front of some inserters? The inserters would be placing on the far side of the belt, which is what the underground belts would cause anyway.

And as the corner issue with items on belts decompressing is fixed, it shouldn't be an issue either.

Just curious

[Hammerchief]

What is the point in the underground belts in front of some inserters?

It's most compact way to make two adjacent inserters use both sides of belt. When you use normal belt piece it will become corner piece and inserters always place items on the inside lane of corner belt, so both inserters would place items on just one lane and one of them would unload much slower than other one.


EDIT: Don't take next designs seriously, you should continue to next posts and use this for both one belt per wagon and one belt per two wagons unloading, unless you hate unused space.


There is my take on unloading two wagons onto two belts:

Unloading two wagons onto two belts

factorio_unload_1.jpg (142.59 KiB) Viewed 20046 times

Whole part takes just three rail-widths. Inserters are connected to ensure chests will be unloaded rougly at the same rate. Ones on the outer side has disadvantege in joining output, so I just read what they are holding and slow other ones as shown on image. Six is just number that I found works reasonably well.


I also tried to make most compact unloading from two wagons to one belt, here showing two such stations:

Unloading two wagons to one belt

factorio_unload_2.jpg (191.89 KiB) Viewed 20046 times

This time is ensuring same unloading rate more messy. In the red circuit I'm reading content of outer chests and translating it in combinator to signal A. Green circuit is giving this A-signal and also content of inner chests to inserters I want to slow down. Inner inserters are then comparing whatewer is in chest (anything signal) to A, working only if inner chests holds more than outer ones.

[vanatteveldt]

Heh, good thinking: if the goal is to have 1 belt per wagon, you might indeed also just have 4 inserters.

But in that case, the problem is a simple 2-to-1 or 4-to-2 balancing, so why not just use a splitter to merge the resulting 2x2 lanes into 2 lanes?

[Rage]

This is the setup I'm using at the moment.

This is with full research completed.
Only needs to be two cars deep to fully saturate both belts, the additional are because it replaced an older system.

[vanatteveldt]

@Rage: Why do you unload to 4 chests, insert two into the other two, and then unload these two? For the extra buffer capacity?

[Rage]

@Rage: Why do you unload to 4 chests, insert two into the other two, and then unload these two? For the extra buffer capacity?

Yeah, it's for the extra buffer. I could do the 6 insters, 6 chests 6, inserters setup, but only the outer most inserters would ever really be working, so this works more than well enough for me.

[Hammerchief]

...so why not just use a splitter to merge the resulting 2x2 lanes into 2 lanes?

There is no reason not to, splitter is doing perfect job here ensuring full saturation while unloading chests at the same rate. At the unloading station I posted on second image I could not use splitter for it takes too much space and for some reason I was stuck at thinking I can't use splitter even in this case, where clearly is enough space.

[vanatteveldt]

@Hammerchief: I would think that using lane merging rather than splitting is what is causing the unloading imbalance, which in turn means that you need to use the circuit conditions. By merging to an underground belt you can do the first (4->2) merging in a balanced way, and using a splitter for the remaining 2->1 means that it should unload in a balanced way, right? (although I guess if one lane is consumed faster than the others it might still cause a problem)

[Hammerchief]

You are absolutely right, I will now rather use splitters too. Stalled belt lane is always problematic, but it will not break anything here. Some chests will just unload more slowly, but you can always build lane balancers and buffers to deal with that.

And becouse you dislike my beautiful circuits so much, I also redesigned super-slim two wagons to one belt unloading station. It now uses splitter to balance and is now truly just two tiles wide. (Taking output to another station was kinda cheating anyway.) While mirrored, it can support unloading four wagons to two belts while still being two tiles wide.

Brand new unloading, now with splitters!

factorio_unload_3.jpg (87.45 KiB) Viewed 19890 times

[vanatteveldt]

That's pretty nifty, cool! Smart solution to get the second pair of inserters to use both sides!

I've actually decided to drop the intermediate chests, as stack inserters have pretty good throughput to a belt now and (in this particular case) the belts provided enough buffer, but it's nowhere near as compact.

[siggboy]

I think most of the setups shown here are overengineered.

First of all, if you want a chest balancer (for unloading), do it like shown here: Balanced Buffer.
It's probably better to balance the output belts, though, if it's not too many belts that's easy enough to do with splitters.

Also, I don't see a reason why you'd have 12 buffer chests at a wagon, but then unload to fewer than 3 belts. Is it only to make unloading time (from the train) slightly faster? That doesn't make a difference in practice if you can only consume the items from the train at a slow rate.

Let's say you have 2-wagon trains, and you unload these onto 2 blue belts. So that's 4,800 units per minute that the train station can supply. Therefore you need to unload at most 4,800 units of ore per minute at that train station to keep the belt saturated. Any more than that will only fill the buffer and do absolutely nothing for your factory throughput.

Now, unloading 4,000 units (one 2-wagon train) from the wagons into the chests takes about 17 seconds if you have only four (!) stack inserters per wagon. Is that not fast enough already? You only need 1.2 trains per minute to saturate a blue output belt per wagon. If the trains take 6 seconds to unload instead of 17, it's not going to increase your throughput effectively in that scenario. The train will leave 10 seconds earlier. It doesn't mean anything.

To unload onto 1 blue belt per wagon is trivial. Just take the high performance unloader and scale it down to 4 inserters. Done.

Ore in buffers is practically wasted ore, until it is consumed. So how big the buffer is doesn't matter as long as it's big enough to bridge the time between train deliveries, so your output belts will stay saturated.

If anything, one should try to make the buffers as SMALL as possible, not as big as possible.