An industrial furnace with a hopper sorting system is displaying different results between survival and creative. The same sorting system in creative works perfectly, however in survival, items travel through hoppers at an inconsistent speed 'skipping' one hopper when trying to distribute fuel evenly across the furnaces.
Note that on initial construction of the sorting system, it worked, however after some more time played on the map the problem occurred. Any new fuel added to the input will now 'skip' the third furnace.
I have copied the sorting system out of the survival game and in to a creative game using MCEdit, and the issue does not occur in the creative map with the exact same item layout.
I believe this to be a game-size or map-size issue, or potentially a chunking or objects loaded in to memory issue. The creative map (where everything works) is 5.7mb, whereas the survival map (where it does not work) is 12.7mb. The system stopped working after exploring more of the map, creating a new building and herding some cattle.
SPIN:
Situation: An industrial furnace has two distribution systems; one for raw materials and one for fuel.
Problem: The fuel distribution system is not spreading fuel evenly across 8 furnaces, more specifically, the third furnace is 'skipped' entirely.
Implication: Only 7 of the furnaces get fuel, meaning that one furnace is never fired.
Need: The hoppers must distribute items evenly and consistently across the board.
Links:
I'm adding these links through DropBox as one zip file is 12.7mb (too large to attach)
https://db.tt/94bhg4zc (Creative world with working sorter)
https://db.tt/wfwtVh4d (Survival world with broken sorter)
Replication Steps:
1) Add 8 coal to the 'Fuel' input on the industrial furnace.
2) Wait 10-15 seconds.
3) Inspect the contents of each furnace, the third furnace will have no fuel.
Note that this is the same with any amount of fuel, divisible by 8 or not.
Linked issues
Comments 10
Thanks for your detailed analysis, Doug. Apologies that in the original issue raised, every time I noted the 'third' furnace being the broken one, it was actually the 'fourth' being broken, thanks for pointing that out.
I used scenario c in your above list to resolve the issue, however replacing the hoppers above 2 and 3, while fixing the issue with furnace 4, creates an issue with furnaces 1 and 2. You don't notice this issue with a stack of 8, however if you use 16 fuel, furnace 1 gets 3 fuel, furnace 2 gets 1 fuel, and the rest get 2 fuel. This difference increases with larger stacks, essentially furnace 2 only gets 1 fuel (the last to be dropped), and the rest are distributed evenly.
Note that all problems go away when you replace the entire row of hoppers at the same time; I just tried this then added 8, 16, 40, then 5 stacks of fuel consecutively, checking each amount distributed properly.
Note that the pulse extender has no bearing on the beginning of the distribution, only the end to ensure that the last 1-8 units of fuel are dropped successfully; without it, the distributor was dropping fuel from the first 2-3 hoppers too quickly when the chest emptied, leading to more items in the first 2-3 hoppers. The pulse extender inputs to an AND gate, meaning that when the input chest has items, the signal immediately switches off, but when it empties, there's an 8-tick delay before outputting a signal again.
Copy-pasting the schematic in a creative or survival map resolves the issue, and now that I've replaced all the top hoppers, the issue is also resolved. It seems the bug here is more a question of the order that the hoppers are placed in, potentially causing varying speeds of input to adjacent hoppers. My guess is that if you place the hoppers in order 1, 2, 3, 4 then there is a consistent speed, but if you place in the order 1, 3, 4, 2 there is a fractional reduction or increase in speed to hopper 2.
My current guess is that hopper inputs/outputs work on a BUD mechanism which perhaps bugs out if you place blocks in a non-uniform order, then applying a uniform redstone pulse to the hoppers doesn't communicate well with the BUD.
Is this still a concern in the latest Minecraft version 14w03b? If so, please update the affected versions in order to best aid Mojang ensuring bugs are still valid in the latest releases/pre-releases.
Re-tested in latest version and latest snapshot, this is still an issue. Moreover, it appears to be an issue when exiting and reloading the game.
You can resolve the issue by relaying the one row of hoppers, the issue will no longer be there for the duration of your play, however on exiting and reloading, the issue will return.
For the furnace distribution system in question, this means I need to replace 9 hoppers every time I want to distribute coal between my furnace array each time I use it. Not a massive inconvenience, but still an issue nonetheless.
Is this still a concern in the current Minecraft version 14w11b or later? If so, please update the affected versions in order to best aid Mojang ensuring bugs are still valid in the latest releases/pre-releases. - bot
Is this still a concern in the current Minecraft version 14w30c or later? If so, please update the affected versions in order to best aid Mojang ensuring bugs are still valid in the latest releases/pre-releases.
This ticket is incomplete without the requested information, no response has been received within a reasonable time and we are assuming this is no longer an issue. If you are still experiencing this issue, we can reopen it at your request.
Hi Alex, this is still an issue that has not been resolved or looked at. Sorry, I don't have the time to retest in every single snapshot. My current workaround is to clear down a row of hoppers and replace them any time I want to use my industrial furnace. The bug reappears on logging out and back in to a game or unloading and reloading the chunk.
Reopened, thanks.
Also sorry for the inconvenience, I just started making plans on how to properly do this "Awaiting Response" thing: What I am expecting at least from anyone reporting a bug in the future is that the person checks if it still applies in a major release (1.9 would be the next one).
I think it's a dupe of MC-105560
Your survival map as supplied has furnace 2 with 2 coal and furnace 4 empty. Furnace 3 seems fine. I can reproduce this reliably by putting 8 coal into the chest.
I created each of the following scenarios with a fresh copy of the supplied survival world:
a) If I replace the top hopper above furnace 2 and test, there is no change.
b) If I replace the top hopper above furnace 3 and test, furnace 3 now receives no coal instead of 4.
c) If I replace the top hoppers above both 2 and 3 at the same time, the problem goes away and distribution works as expected.
d) If I replace the top hopper above furnace 2, test, then replace the top hopper above furnace 3 and retest, the outcome is as per b) above.
e) If I replace the top hopper above furnace 3, test, then replace the top hopper above furnace 2 and retest, the problem goes away and distribution works as expected.
It probably works in creative because the hoppers were recreated when you pasted with MCEdit. Have you tried copying it within the survival world? Does it then work?
P.S. The additional redstone circuit with the pulse extender complicates matters. Unfortunately, It allows the first couple of items to drop into furnaces before turning the filters off. This is what causes more than 1 item in furnace 2 above.
If you make the hoppers 3 high instead of 2, the bottom one can take from the filtered hopper without the need for an extra delay circuit. This also clarifies the problem by having 1 item in each furnace except 4 and a second redstone pulse from the last hopper when the item that did not drop into furnace 4 hits the end of the hopper train and drops into furnace 8, IYSWIM?