I was building an item sorter for my gold farm. Since the drop rates were high, a normal hopper line was not fast enough to move and sort all the items. I built a bunch of tracks to allow a few hopper minecarts to transport all the drops.

However, when it came to the swords (non-stackable), I was having issues. I looked at the mumbo jumbo video Mumbo Jumbo video. That idea worked, but I tried to tweak it to my settings. I used a detector rail to check for the item type in the minecart. The detection works fine, but the activation of the rail when the minecart goes over it locks the hopper below, and the swords do not get sorted.

Is there any way to fix this setup?

1 Answer 1


The problem of detector rail locking the hopper is an age-old problem of using it in minecart unloaders. There are two general approaches:

  1. Use another hopper minecart partially embedded in a transparent block under the detector rail to pull the items; use an activator rail to lock/unlock it. It's important the block is transparent so that the detector rail doesn't power it up (activating the activator rail, locking a normal hopper underneath the minecart, and other headaches). To embed the cart like this, first use a fence/wall to stop it after rolling it partially off the activator rail, then zero-tick the transparent block into it (push it with a piston activated by a button attached to its side; the button pops off in the same tick the piston is activated, as result the block doesn't nudge the minecart).

enter image description here

  1. Stop the minecart partially on the detector rail, partially on a rail on top of a hopper. Make sure the block under the detector rail is transparent.

enter image description here

  • I would usually go for approach number 1. you can even remove the top rail and replace that glas block with a solid block which you then can take the comparator output from which allows you do install a lock/unlocking system in a 1 block wide space!
    – Chund
    Jan 11, 2021 at 11:02
  • That makes sense. I shall give it the first one a try. However, I sense that I wouldnt be able to constantly run the upper minecart in a continuous loop(I wanted to have multiple minecarts running at the same time). Jan 12, 2021 at 15:04
  • 1
    @AbilashReznovSubbaraman I'd suggest you unload everything from the minecarts using a high-speed serialized unloader, dump it all onto an iceway and use regular sorters to sort items bumped by slime blocks along the ice (or if speed allows, just use a hopper line instead of iceway). Sorting directly from a hopper minecart is a pandora's box; sooner or later you'll encounter a caveat of the minecarts that makes something essential impossible.
    – SF.
    Jan 12, 2021 at 16:14
  • Do you have a world file or a tutorial I could take a look at? I didnt not seem to find one(perhaps i am looking under the wrong name) Feb 8, 2021 at 23:07
  • @AbilashReznovSubbaraman What do you need - or what do you want to achieve?
    – SF.
    Feb 8, 2021 at 23:25

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .