Adding Steel to a Smart Furnace

[cjmarsh]

I've seen the concept of a Smart Furnace implemented in a couple places and the idea struck me as a good one, a furnace infrastructure that smelts the type of ore you need when your supplies are low. I've managed to implement a basic one for iron and copper with relatively little effort and a circuit network but I run into problems when I try to add in steel. It's not the logic circuits that trip me up but rather the switch from steel to one of the other types tends to leave a number of iron plates behind in each furnace that didn't form a full steel crafting cycle before the smart furnace attempted to switch to another ore type. I'm trying to wrap my head around some way to either extract the plate from the furnace if steel isn't on the menu, or maybe use some kind of buffer management for the input. I'm not aware of any way to do the former and the latter seems complicated and I doubt I'd have room to implement it inside my beacon layout. Does anyone have any thoughts on the matter or have any experience messing around with steel in a smart furnace?

[terror_gnom]

I havent build a smart furnace yet, but I would try to give each iron inserter a delayed signal, so if the furnace should be working on iron or copper, but is blocked it will smelt steel until it can take iron ore or copper ore.

Like:

1 tick: copper-ore inserter true, iron plate inserter false
2 tick: copper-ore inserter true, iron plate inserter true

so iron plates will only be inserted, if the furnace is blocked by iron plates.

An other possibility is to check the ironplate chest for 5 iron plates and disable steel-smelting as long as there aren´t 5 iron plates in the chest. You would need to guarantee that the inserter picks up exactly 5 per cycle though (inserter stack size bonus 5 seems handy^^).

[twepy]

Its possible to do it without inserter stack bonus, but it requires a S/R latch. Smart inserter 1 pulls iron plates of belt (prevent stack bonus here!) and puts them in a smart chest, the input side of the s/r latch is connected to the chest and when 5 plates are in the thest, the set signal becomes active which is connected to both inserters. This signal disables inserter 1 and activates smart inserter 2 who removes the plates from the chest, when the amount of plates in the chest reaches 0 the reset triggers, this removes the set signal and disables inserter 2 and activates inserter 1.

A pic says more then 1000 words

SR-latch.png (480.23 KiB) Viewed 4956 times

[vanatteveldt]

I described my smart furnace setup here (viewtopic.php?f=8&t=25114) and here (viewtopic.php?f=8&t=24938), inspired by MeduSalem's design in viewtopic.php?f=5&t=13107&start=10,
but that indeed relies on inserter capacity of 5 and checking for iron>4 in the input chest.

My "innovation" was to include a control system that smelts only the ore in highest demand (up to a certain max value) by putting a dummy signal on the logistics network.

[cjmarsh]

Thanks for the input everyone. I hadn't considered the stack bonus size of 5, that's a good idea. I used the idea of the >4 condition for the stack size bonus vanatteveldt, but I used a buffer chest instead to make two different networks for the different checks and it still gives enough space for surrounding beacons. This let me use a local network for the control system to get the type of ore for smelting so there isn't any item off-limits in the logistics network. I'm using simple arithmetic to compare the logic but I'm not sure if I have the most efficient method or not so if anyone sees a way to improve it please feel free to chime in.

factorio_furnace.png (960.81 KiB) Viewed 4888 times

[FMTK]

Both working but still not expandable ... working on it

[vanatteveldt]

@cjmarsh

I've not tested your design, but I could see two potential problems:
1) what happens if all plates are at exactly the same level?
2) I think it is inefficient for the smelter to change its recipe, as it takes a quarter second or so for the new ore to be inserted, while if it has the same ore it is already loaded

For this reason I smelt X if X is at most 100 higher than the lowest one, so in many cases more than 1 thing is on the "can smelt" list. This adds a bit of smoothing to production and prevents recipes from being switched after every smelting step.

I like your solution with the extra buffer chest. I was planning to use smart beacons as well, but with logistic chests the system wastes so many level3 modules that I can't justify it. I just realized I could use a belt instead and manually insert the two speed modules, I could have a go with that.

[cjmarsh]

@FMTK
The image is just an example of the setup, the circuits on the right are for the entire furnace and the furnace setup on the left can be repeated as many times as necessary so long as the three smart inserters are connected to the large red circuit network. It is also possible to place a line of beacons between lines of furnaces so that 8 beacons affect each furnace, vanatteveldt's base thread shows an example.

@vanatteveldt
1) since there is no greater than or equals sign the default value is steel production
2) I hadn't considered the time it takes to switch out the ore type and I think you might be right, but wouldn't the inserter with the new ore type immediately activate and hover over the furnace while the previous ore was still smelting? Even still there would still be some small overlap so I'll see if I can work on that.

Also, I saw in your thread that you used productivity modules in your furnace instead of speed, was there any reason for that or did you just want to save on resources?

[vanatteveldt]

Depending on how many beacons you use, productivity can actually be as effective as speed, since more speed modules are additive but speed and productivity are multiplicative: output = productivity * speed, so the extra speed is multiplied by the 1.2 productivity bonus

Concretely, in my setup the smelters in the middle have 10 effect sources (2 modules and 8 beacons from columns on both sides of the smelters), so they can have either 8xspeed + 2xprod, or 10xspeed.

10xspeed gives crafting speed 12, so every second it produces 12 / 3.5 = 3.4 ore.

8xspeed + 2xprod gives crafting speed 9.4, so every second it produces 9.4/3.5=2.7 plates directly, but the productivity adds 20% for 3.2 plates in total, but consuming only 2.7 ore

If you surround every smelters with 4 more beacons, the productivity actually wins out, producing more ore per second:

14 speed gives crafting speed 16, producing 4.57 plates/s
12 speed and 2 prod give crafting speed 13.4, producing 4.59 plates/s consuming 3.8 ore.

If you don't use beacons productivity is horrible, but if electricity usage is not a factor the combination of productivity plus speed beacons is pretty hard to beat. 20% extra production might seem small, but if you consider the whole chain it can really add up. Example: since the copper ore consumption of a blue circuit goes through 5 stages with productivity modules of which 4 have 4 module slots (smelter has 2, ass3 for cable+green+red+blue have 4), suddenly you have a saving of 85%, requiring 6 copper ore rather than 40, which is quite massive.