Elevator Timing Trouble! (Possible Bug?) [With video]

[TheYaMeZ]

I've been working on a caged elevator that opens and closes. The elevator used to work when it was just an open cage but since installing some extra gadgets, no longer seems to sync properly when going upward. The thing is, when I completely disable/remove all the new stuff the sync problem still exists.

So heres an overview:
2 Pulleys.. powered by two different gearboxes (controlled by the same circuit).
Going down? No problem! Elevator stays together all the way down.
Going up? The elevator snaps in half with one side rising slightly before the other with half a block in height difference (slightly more sometimes).
Reproducability? I'd say 90% of the time it does this. When I first tried to make a video on my issue, it worked perfectly (and I didn't even change anything!)

Heres my video on the issue. Its a short video and I apologise for sounding pretty dazed but I was in a quite defeated and disheartened state =P.

http://www.youtube.com/watch?v=e7vi7r7CdDw

I kind of want to keep this video between us forumites for now until its fixed and has its glorious first official ride.
Can anyone tell me what i'm doing wrong? Is this a bug? I'm hoping Flower has the time to cast his benevolent (or malevolent?) gaze on this to tell me if its a bug or not.

[Thalmane]

Does this issue happen if it's only a flat platform? One issue is you could have built your elevator on two different chunks. That seems to always cause timing issues with anything.

[TheYaMeZ]

Does this issue happen if it's only a flat platform? One issue is you could have built your elevator on two different chunks. That seems to always cause timing issues with anything.

I thought it could be something like that, and I haven't ruled it out, but the thing is that cage used to work pretty much every time.. I'm not sure why it isn't anymore, I havent changed any circuitry relating to it.

[Urian]

Weird. As Thalmane said, it might be because of chunk lag, either at the gearboxes or pulleys. One easy way to check that is to look at the coordinates (by pressing F3), since a chunk is 16*16, if the line where the elevator "splits" has a value that's a multiple of 16, then it's crossing a chunk.

[TheYaMeZ]

Weird. As Thalmane said, it might be because of chunk lag, either at the gearboxes or pulleys. One easy way to check that is to look at the coordinates (by pressing F3), since a chunk is 16*16, if the line where the elevator "splits" has a value that's a multiple of 16, then it's crossing a chunk.

Hmm didn't think of checking it like that! I just checked and it seems its not on any boundary on x or z. Get this. I just loaded the game up for the 5th time and now 4/4 tries it has worked. I don't understand why its so unreliable =/

Edit: ok it has worked 4/5 times now.

[Thalmane]

Maybe try and cut the power off where it splits for the two pulleys?

[TheYaMeZ]

Maybe try and cut the power off where it splits for the two pulleys?

I think I tried that... The problem there was my elevator is 4 blocks wide and I couldn't position the gearbox where the power is split in a way that both routes would be the exact same length.

That is what your trying to say right?

[Thalmane]

Yes that's what I mean. I don't believe there should be more of a delay with more axels. Gearboxs cause the delays so as long as there isn't more gearboxes on one route than there is on the other it shouldn't matter. Or atleast it shouldn't matter 0.o

[FlowerChild]

Yes that's what I mean. I don't believe there should be more of a delay with more axels. Gearboxs cause the delays so as long as there isn't more gearboxes on one route than there is on the other it shouldn't matter. Or atleast it shouldn't matter 0.o

Correct. Axles transmit power instantaneously (like redstone wire), so the only thing that should make a difference in cases like these is the number of GearBoxes.

I'm still thinking this one over, but unfortunately it looks like timing issues inherent to the Minecraft code-base :\

[TheYaMeZ]

Thanks for the comments and advice everyone! Very happy to see you having a peek flower =D.
If you need any more information like a save file or something to get down to the bottom of it just say the word.

I guess i'll redesign the gearbox area like Thalmane suggested and see if I can use that for timing to see if it makes a difference in this case.
I'll report back here with any findings.

[TheYaMeZ]

I just had a thought, this issue started after I built that piston door opener thing. At first I assumed that it was intefering somehow, but after many checks I confirmed that the systems were isolated.

Is it possible that the amount of redstone in a chunk can affect the timing of devices such as pulleys? So maybe the schedueller was caught up in checking other redstone devices that one of the pulleys was delayed to the next tick. Does that make any sense? I'm not familiar with the minecraft source code so i'm not really sure.

[Battosay]

That's possible. I had the very same problem in one of my elevators, and it was the one in the very middle of my Batcave (so full of redstone devices everywhere).
But I solved it by applying the redstone signal to a single GB who splits in two to power the two pulleys, and not on the 2 GB next to the pulleys. It add some delay, but no more timing problem.

[BigShinyToys]

I hade a simlare probblem with my main Bedrock to surface elevator. i found the probblem in my case was i was using to meany reperters in my wiring and it caused the game to glitch . Q: douse youre game run smothly or douse it glitch ?

[TheYaMeZ]

That's possible. I had the very same problem in one of my elevators, and it was the one in the very middle of my Batcave (so full of redstone devices everywhere).
But I solved it by applying the redstone signal to a single GB who splits in two to power the two pulleys, and not on the 2 GB next to the pulleys. It add some delay, but no more timing problem.

Alrighty, that was suggested earlier but since you said it fixed it for you I guess that seals the deal, thanks!

I hade a simlare probblem with my main Bedrock to surface elevator. i found the probblem in my case was i was using to meany reperters in my wiring and it caused the game to glitch . Q: douse youre game run smothly or douse it glitch ?

Actually the up/down circuitry of the elevator doesn't use any repeaters.. so I ruled that issue out, also my game runs smoothly the whole time so I don't think it was performance.