Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[Andrakon]

I built a magma sea to surface magma filling minecart system detailed at http://dwarffortresswiki.org/index.php/Magma and http://www.bay12forums.com/smf/index.php?topic=125679.msg4217863#msg4217863

But I wanted a super dwarfy way to collect the minecarts from the system between lava hauling runs. So I built an automatic cart return system for 8 carts. This system took about a week to get right due to experimenting with every part of the lava delivery system. I also had to rebuild the cart return system almost completely once due to carts jumping between lanes.

Picture 1 Cart storage


After launching the first cart from on top of a hatch it goes down one z-lvl onto a wiggly lane and hits a pressure plate, sending the next cart down its lane, hitting another pressure plate, and so on. This ensures I have at least 100 ticks between cart launch. This setup probably gives me a little over 150. The minecarts are locked in their own little rooms with doors hooked up to a lever. This is to keep the carts from rolling off of their hatches during reloading.

Picture 2 Cart timing


Each of those pressure plates is also hooked up to a gear on top of a latch. A latch is a complicated bit of engineering that is basically a small bit of memory. Detailed at http://dwarffortresswiki.org/index.php/File:Mini_Resetable_Trigger_Once_Plate.PNG. Activating the gear resets the latch so the hatches in picture 5 are closed and not open. It does this by removing water from above a pressure plate that is on the bottom of the latch in picture 3 (shown without water in it).

Picture 3 Latch pressure plates


After dropping the carts down a hole to the lava sea, they run through a simple system to fill the carts with lava and send them on their way back up a 104 z-level stack of loopy impulse ramps where a track stop dumps the lava into a resevor. They then drop down the up/down stairs to the lava sea and do it over again. A good cart filling system is described here http://www.bay12forums.com/smf/index.php?topic=125679.msg4247715#msg4247715 but without the bridge on the ramp. The carts can be dropped from any height onto where the bridge is supposed to be in that post, but I put a 2 long iron roller in the trench on top of the 2 track engraved ramps. So the carts get dropped onto a roller in a 2 long trench of 7/7 lava with a pump constantly filling the trench. I would show a picture of my setup but I was experimenting and ended up with a much more complicated setup that I don't care for as much lol.

Picture 4 Cart return hatch


But if I want to collect the carts out of the system I pull a lever and the hatch in the above picture opens up, grabbing the carts out of the system. I am storing the lava above my fort so this is somewhere near the top of the system and the carts are caught before they are dumped in this case.

Picture 5 Cart return system


The carts are dropped one z-level onto a NS track ramp, go south then east and the first cart rolls over the first hatch and activates the first pressure plate. The pressure plate is attached to the hatches in the latch at the top of picture 1. They normally have 6/7 water on top of them. This will open the hatch dropping the water onto a pressure plate in picture 3 and this activates the hatch right behind the pressure plate that just got ran over in picture 5. This keeps the hatch open until the carts are launched again, allowing additional carts to drop down on the ramp under the hatch go up another ramp and end up in the next hallway, running over the next hatch and pressure plate activating those, until all of them are activated and all the carts are returned to their proper starting positions. Note some of the lanes have additional impulse ramps before the hatch. I had to put these specifically on ONLY those lanes or a cart would get stuck. Your mileage may vary and you may need to put more or less impulse ramps to make it work. Also the walls between the lanes were absolutely necessary! My first design didn't have them and most carts would jump lanes when they went over the hatches.

Also in picture 5 is the top of the drive train for the latches. Each latch uses 30 power if you include 2 pumps and 2 gears for each latch. I only need 7 latches for 8 carts because the last cart does not need one. I also left some room for expansion encase I want 10 carts. The right of the drive train is hooked up to 2 dwarven water reactors producing a total of 400 power. I don't use all of it but I would be cutting it close if I expanded to 10 carts and 9 latches.

In the spoiler is all the pictures arranged from top to bottom.

Spoiler (click to show/hide)

[WanderingKid]

That, my good fellow, is quite the dwarven engineering feat.  I personally dislike arguing with latches in roughly any form other than 'lever', so that is quite cool to see what can be done when it's used well. 

[Andrakon]

That, my good fellow, is quite the dwarven engineering feat.  I personally dislike arguing with latches in roughly any form other than 'lever', so that is quite cool to see what can be done when it's used well. 

Thanks! The hard part is coming up with the idea, researching all the pieces I don't know anything about like the latches, and the first build was tough and complicated. The rebuild was easy because I knew how everything worked by then. Building latches is like dipping my toes into the ocean of dwarven computing! I found so much stuff about it on the wiki that I may play around with it sometime. I made a calculator in minecraft, maybe I can do it in Dwarf Fortress! XD

Minor details:
Anyway this thing has some other deluxe extras. In picture 1 the first minecart's hatch is dropped not by lever, but by pressure plate. The only pressure plate you can see in picture 1 to be exact. The lever below it is a dummy lever that is not hooked up to anything! It is just there to get someone to step on the pressure plate, this way I don't have to pull the lever twice. In picture 5 at the top left, the left (currently on) lever is hooked up to the 7 gear assemblies also in that picture and thrown before I attached the pressure plates in picture 2. This allows them to have the opposite state than they normally would by default. It also acts as a nice reset lever. And the right lever in picture 5 (currently off) is hooked up to the latch's hatches in picture 1, to serve as a reset for the off state, turning the latches on instead. And all the doors in picture 5 are just maintenance access.

[Merendel]

Just out of curiosity is there any particular reason you set out to design this system to enforce a 100-150 tick gap between the carts?  As far as I'm aware for a simple cart powered magma pump its fairly common practice to simply use the cart stacking mechanic in the drop shaft with the launching system disabled when the player desires to turn off the pump.  Not that this isnt epic in its own right I'm just curious why you chose this over a minecart stack (which launches carts at about 8 tick intervals)

Also you could probably design the state cells in such a way where the pumps are irrelevant.  This would work best if you had an aquifer but a sufficiently large cistern would also work as long as you refilled it on ocasion.  Anyway each cell's presure plate is set to react to 7/7 water.  Hatch above the plate with the water source behind it.  When you want to set the cell to the on position you momentaraly open that hatch just like you do now.   Instead of useing a pump to pull the water off the plate simply have a door next to it linked to your plate that turns the cell off.  When the door is trigered it opens and the water level on the plate tries to flow through the door.  You could have a drain of some sort on the far side of the door but its not really needed.  Either way the water on the plate is no longer 7/7 so it will deactivate in 100 ticks.  When the door closes it will delete any water on its tile so no issues with repeatability. Might be a few ticks slower than useing the pump but then agian you dont have to deal with supplying power either.

[Larix]

I concur, nice engineering there. I suspect you could have done without the latches if you had made use of the peculiarities of DF signal processing (like sending a hatch an extra 'on' via pressure plate to close it 100 steps later, regardless of current lever positions or held latches).

I currently prefer playing with roller-propelled minecarts; it may require power and the related infrastructure, but it makes the final designs _so_ much more compact (and utterly intransparent!).

I made a calculator in minecraft, maybe I can do it in Dwarf Fortress! XD

Good luck on that path. DF-buildable binary adder/subtractors are well understood and i'm not sure there's much space for optimisation of the basic design(http://www.bay12forums.com/smf/index.php?topic=15096.msg4600870#msg4600870, five bits, full installation), but making a better multiplier would certainly be a worthwile endeavour.

[Sutremaine]

You can make pressure plate latches without using water. You need two overlapping loops of track ( like CO ), and a way of switching the minecart between the short/inner loop and the long/outer loop with a lever pull. Then you put the pressure plate on a section of track that's part of only one of the loops.