Questions about Steel and Alloy Production in the Crucible

Hi guys, when my new smelter consumed all the magnetite I have, I’ve decided to change the recipe and smelt some hematite. My intention was to put into crucible 5 limestone dust(1st hopper), 4 purified coal(2nd), and 10 purified hematite(3rd), some of which will stay in the pipe until the first portion of iron is transformed.

It took 2 deaths before I discovered that hoppers drop items at the wrong order. 2nd hopper (4 coal) goes first, 3rd hopper (10 hematite) goes second, and then 1st drops 5 limestone into the pipe because there is not enough space in the crucible.
Result: Some tasty potatoes, brand new steel boots, and nice bronze pincers that I made using my first bronze are burned. -_-

I kind of made this setup work by swapping hematite and limestone places. But why is it works in 2, 3, 1 order? Is it random? Can it change spontaneously and boil me again? Can somebody explain?


The Issue is not your Hoppers, it is that you use Item Pipes in such a critical Setup.

What you should have done is use a single “Queue Hopper” prefilled with all Ingredients you need.

Or that you should test your Redstone before actually wasting things, you know you could just place a Chest where the Crucible is and see if it works before wasting Materials, right?

If you set 3 Hoppers to emit an exact amount and pulse them once with Redstone, they should give you the proper ratios too. Then you obviously need to wait until the path to the Crucible is empty before you pulse it again, or use a Queue Hopper after those 3 normal Hoppers to make sure the Order is kept.

Just do NOT use Item Pipes for this, its not going to be stable if you do that.

Edit: Also maybe dont flood your Crucible so hard if you want to make Steel, the Air from the “Bellows”/Engine needs actual space to fit in there too.


Thanks for reply, yeah, after 2nd death I’ve debugged this using chest. I’ll try to change this setup later. Maybe using a queue hopper, or repeaters between hoppers. [Or I Can just add shredder to my ore processing zone and start using normal recipes]

P.S during tests in a secret “lab” at the cave under my base I’ve examined that steel production requires around 2/3 ku/t per 1 hu/t of burning box output. Am I right?
My final test setup was 1 Dense bronze and 1 Dense invar boilers (320 steam) connected to a strong steel engine (80 hu/t). It worked pretty well with 14 magnetite, 4 purified coal, 1 coal per pulse, giving 100% output of steel.

Also I intended the air problem, you mention. But it’s occurred that this build a little over produces kinetic energy, so I didn’t encounter it (Another problem is that the crucible might melt down faster than the next portion of resources reaches it. Using 8 nuggets of some metal solves it.)

At my base I used a temporary setup of a bronze bb and bronze steam engine powered with bronze+invar boilers to make a few stacks of steel too with the same 14-4-1 recipe. No problem here too, except slooooooooowneess.


1 KU = 1L of Air, 1000L Air = 1 Unit of Air, so you need 1000KU total per Unit of Steel. if you can supply it in one blow of an Engine it would instantly convert Iron to a whole Unit of Steel for example.


hmm. FTB wiki says that 1 HU will raise the temperature of 100 kg of mass by 1 K. So heating 875kg of iron to Δt=1760K (env temp counted) requires… exactly 15 400 HU. (Or ~6 secs using chromium bb. Checked it in a lab right now. It’s correct.)
Are you sure that 1000KU is needed? Basic chromite engine can produce that amount in 10 ticks. Not 10 000? As I wrote before, my setup includes an 80ku/t steam engine, which is able to produce around 10 000 ku in 6 seconds. [Or maybe I just lose a zero somewhere {but I don’t think so}]

15 400HU / 10 000KU = 1.54HU per 1KU
15 400HU / 1000KU = 15,4HU per 1KU
Which means I calculated it kind of right. My 2/3 ku/t per hu/t is 1.5 hu/t per ku/t. (If I calculated it right now)

Thanks for replying again. I remembered the good old times, in school, then I loved physics exercises.
(But solved ‘em almost every time wrong)

P.S Unit of steel is an Ingot as I count or nugget or 0.1pt? Hell there is around 10 times difference. Good night anyway.


Remember Engines have a Push/Pull thing going on, so half the time they pull instead of pushing, and only the push energy is actually blowing Air in, which makes it 2000KU total per Steel Ingot (while technically only using 1000KU).

Please be aware that Air instantly escapes the Crucible if it does not get used up in the Steel Process, so if you dont have the total end Temperature needed to actually smelt Steel, then do not run the Engine at all, it would be quite wasteful to do while you cant even make Steel at the too low Temperatures.


oh. It’s more complicated than I thought. The strangest thing now is that all my stuff works right as I expected.


LOL. Just understood why I need to set my sensors to “magic” 2270 degrees as for bronze bb, as for chromite. I thought there are some ticks needed for “pieces” of iron transformation.


You can easily make steel with a lead burning box, it just takes ages. :wink:

The Crucible only cools down over time if you dont actively heat it up, so even if you inserted 1HU/t you could eventually reach thousands of degrees, until the thing inevitably melts down.

All you need to have is the Crucible at the right Temperature (see NEI) and all the ingredients inside of the Crucible at the same time. Some Ingredients like the aforementioned Air will escape the Crucible if not used up instantly.

If you hypothetically stopped blowing Air halfway through conversion you might get weird fractions of Steel that cant fully convert to Nuggets, since a 1000th of a Steel Ingot is typically not something that has an Item form.


Using powerless burning boxes is soo boring. I couldn’t live without these chromite ones. I got first before I could afford the safety system, so it was quite challenging to count the amount of coal properly and not blow up myself.

Thanks for help really. Steel smelting is much more clear for me right now.
Please don’t punch me in the face if tomorrow I’ll make another thread asking why one of my boilers… …can not emit steam… somehow… I guess. Hope I can solve it by myself.


It emits Steam once the Barometer reaches the halfway point. :wink:

And if you use regular Water instead of Distilled Water you might need to take an up to 50% loss into account due to calcification.


:thinking:hm, was that the problem?


Yeah the use of Item Pipes was the issue in your case, you MIGHT be able to do it with Item Pipes that have a Bandwidth of 5 or higher, but I would not rely too much on that either.


I meant 1st hopper is at a different chunk than the others. So I thought it could cause problems with the redstone signal. But since you’ve definitely said that pipes are the main issue, I’ll try to change this setup right now.


Chunkborders are only an issue if you actually leave the Area while it is smelting. :wink: