Steps to reproduce
Load
Flip the lever at 2, -59, 17.
Wait a while.
Expected results
All of the hoppers fill up in order one after another.
Observed results
Some hoppers fail to grab items passing over, either sometimes or every time.
When items are aligned and on ice and pushed over hoppers by a slime block, there are gaps in relation to the slime block where hoppers don't collect any items.
In the attached picture, the gaps between the hoppers represent the places where they work, while the hoppers in the picture are unable to pick up items.
To reproduce build whats in the picture (comparators are only to see if a item is collected), throw items between the chest and the slime block, and launch them down the ice. If done correctly nothing should be picked up.
This behavior appears to be consistent in all directions except the last hopper, that ones directional. It's also important to note items must be be touching the half of the chest closest to the piston when launched, otherwise theres no issue.
It may seem like a niche issue, but when combined with other hopper bugs, it makes mass item collection in the nether a nightmare.
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Comments 2
I am not sure what you mean by having cakes on top of the hoppers, but in testing currently on 1.21.72, placing cakes on top of the hoppers does not appear to resolve the issue, and hoppers that previously accepted items correctly on older 1.21 versions no longer seem to work.
I I'm not sure if this makes any difference currently, but the hopper in question in my world on the console edition is currently placed at -206, 124, 56, (124 y height where I am standing, so I guess that is actually 122) and is facing into a blue ice block to the south.
Items align to northern edge of the ice using honey block, resting on obsidian at -196, 124, 55 (124 height where I am standing) with slime block attached to sticky piston pushing items East. (Obsidian block is 10 blocks West of the hopper.)
Pictures hopefully show coordinates well enough, last one with blurry red glazed terracotta zooming past too the next Hopper and beyond, hopper contains this block and should have picked it up.
Being that it’s Xbox series x console edition, I’ve no clue how to get the world to you all, but seed I’m using is -240007605
If there’s any simple way to get logs from the Console edition, I'm working to try.
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When I test this I get inconsistencies but with a different pattern. Here are my results from testing a similar setup but with hoppers beside every ice block, using
[media]:
At first, each item has about a 50/50 chance of being collected by the first hopper or the second hopper (first hopper is in the first spot available after the spot that gets covered by the chest).
On blue ice,
After the first and second are full, the 50/50 pattern continues with the 3rd and 4th hopper.
After the 3rd and 4th hoppers are full, all items go into the 5th hopper.
After 5th hopper is full, all items go into the 7th hopper, skipping the 6th entirely.
On regular ice
After the first and second are full, all items go into the 3rd hopper.
After the 3rd hopper is full, all items go into the 5th hopper, skipping the 4th entirely.
After the 5th hopper is full, items have about a 50/50 chance of going into the 6th or 7th hopper.
Eventually, some items stop moving at the 8th hopper while others go past. This is probably because they retain a bit of momentum in the orthogonal direction and it adds up enough by the 8th hopper that their center is no longer on the ice. If you put cakes on top of all of the hoppers this does not happen.
I think these results show that this issue is caused by the speed with which items pushed by pistons move on ice. Each time the game updates an item position there is a chance that it changes by more than 1 block, so it is never actually over some of the hoppers.