Bay 12 Games Forum

Quote from: noodle0117 on July 03, 2010, 08:37:37 pm

There is always the simple cave in trap which could be built on practically every map
Dig a channel in the shape of a 10X10 square (size can be adjusted accordingly)

mine out all the dirt beneath the square EXCEPT for one tile (this is to prevent the trap from collapsing prematurely
Place a support in the middle of the trap
Link a lever/pressure plate to the support
Dig out the previously mentioned dirt square
Once goblin baddies come, activate trap and watch it collapse on your enemies

I was going to build one these earlier today, but I wasn't quite sure about some things. What counts as a "support"? I was going to build a drawbridge, raise it, dig out the remaining space, and then lower the drawbridge to trigger the collapse. Would that work?

A support is a specific building that will hold up sections of terrain to prevent cave-ins.  It can also be connected to a lever, which lets you can destroy the support remotely whenever you want (for example, when there are goblins under whatever it holds up ).

By the way, bridges do not count as anything for cave-in purposes.  If you end up with a platform that's held up by nothing but a bridge, the platform will collapse.  For more information on cave-ins, check the wiki page.

Spoiler: Design #1 (click to show/hide)

z0:

#####
#+++#
#+#+#
#+#+#
##+##
 ###
  ^

z1:
#####
#=.=#
#=%=#
+=%=+
++*++
 +++
  v

Spoiler: Design #2 (click to show/hide)

z0:
########
#++++++#
#+#++#+#
#+#++#+#
##+##+##
 ######

z1:
########
#=.==.=#
#=%==%=#
#=%==%=#
++.++.++
 ++++++

This design also works quite well with aquifers- dig out the layer above the aquifer for z1, channel the appropriate squares for z0, put in the machinery and use a dwarf to jump-start it and you're good.

Have either of these designs been tested?  (Not in an aquifer; I have a different concern with the aquifer version of #2.)  I've just thought of a flaw that should cause them to fail: there will be no flow in the tiles below the center of the waterwheels, since they are not diagonally connected to the pump's input tile.  To provide flow, there must be open space below the south tile of each waterwheel, and I worry that the system may leak through that tile rather than maintaining non-zero water levels in the pump's input tile (as is required to provide consistent 4/7 water below the waterwheel).

Regarding the idea of building #2 with the lower level in an aquifer, I suspect it will not work.  This is what I think may happen:

• Aquifer fills all tiles on z0 with 7/7 water.
• Pump is started manually.  Pump fills the 3 tiles behind the pump on z1 to 7/7, while aquifer maintains consistent 7/7 water in the input tile.
• Each tick, the pump draws water from the input tile and pushes it back into the aquifer stone (since there is nowhere else for it to go).
• The aquifer refills the input tile (may or may not produce flow in the input tile).
• There is no flow under the waterwheels because the diagonally-connected tiles have no opportunity to spread water into the input tile.

If you test the aquifer version, please report the amount of water visible in the input tile as well as the power output of the waterwheels.  This information should reveal when aquifer filling occurs relative to water spreading, checking of plates and waterwheels, and pump operation.

I'm not sure if you misunderstood or not, which means I should have had a diagram.

Why this:

Code: [Select]

77
7 7
 77
 7
77

and not this?

Code: [Select]

7
7 7
 7
 7
77

The second design will leak water.  It may or may not completely stop working, but I'm pretty sure you'll at least get intermittent power failures.  Consider the following process:

• The pump picks up the 7/7 from its input tile and moves it to the output tile.
• Water spreads diagonally from the northernmost tile to the input tile.
• The pump picks up water from the input tile.  The output tile and all orthogonally-connected tiles on the lower level are full, so the water gets placed on the upper level.
• The extra water on the upper level is now free to go anywhere, which means it will eventually leak out of the system.

I tested it... and it doesn't work as drawn due to a flaw... You can't place a water wheel that way to connect it to a pump...

I instead did the following:



I then from the z level above designated a pond over the pump output square and had water dumped in until the bottom was all 7/7 and the pump output was 4/7.

Manually start it, and you're off with 75 extra power to do whatever with.  I used manual step for a couple hundred steps, and you never see the water change from the way it is in the image above. 

I initially left the water wheel the way you have it in your design, but then to get power to the pump i was using 2 gear assemblies and a 1 square axle and that just seemed like a waste when i could turn the wheel and cut out 2 of those pieces.

Awesome, thanks!  For just a single instance of the setup, the way you moved the waterwheel does make more sense.  The version I had typed up was the one I was planning to use for larger plants, by placing them in groups of four so that the waterwheels all lined up.

Here's a new design I just tested based on the last one:

The two waterwheel tiles with blue lines through them should be open to the lower level.  All other waterwheel tiles should be over a floor.
This gives the same net power as the mirrored design (165), without the stability problems (at least from what I've seen so far).

With some simple modifications, you can even make a version that uses 3 waterwheels to provide 248 net power (untested, but I'm pretty sure it will work):

Edit: Did some testing with replacing the pilars in the original design when mirored with grates and it worked fine but there was a tiny amount of spilling. Not a problem for short term but the water level in the system did seem to go down slowly which could reacha  point where it affects power production. Doors work a charm though.

Cool, I'll keep that in mind next time I rebuild my power plant.

Mirroring the design causes one of the wheels to be unreliable as the power switches from 100 to 200 (didn't notice any 0). adding 2 extra wheels each side created a situation where you get 400-300 most of the time and 200 sometimes (didn;t notice any 100 or 0s)

I hadn't noticed that before, but when I checked, my power plant's total power output was varying between 1500 and 1300.  (This may or may not be the same problem, since I also just noticed that water has somehow leaked out of my system .)

With the mirrored setup, I would guess that the power loss is mainly due to lack of flow rather than lack of water (which is normally the problems with using a single tile beneath each waterwheel).  The next thing to try would be to add 1/7 or 2/7 water to the input tile by bucket after the machine has been started.  This should prevent the water beneath the waterwheels from dropping below 4/7.

On a side note I had a few dwarves fall in there and funnyly enough, This design kicks ass for swimming training. Dwarves without any supervision just racked in the swimming skill fast cause the flow pushed em around forcing them to move (making swimming experience be gained faster). Getting the dwarves out is another story, (although I did notice a few of them actually getting out on their own after gaining the required skill to hop onto the ledges, didn;t pay much attention but this could be compromised depending on design and if its surrounded by walls)

Also good to know.  Hmm... With the extra 2/7 in the input tile, that tile should get up to 5/7 temporarily when water spreads into it.  Depending on when, during the course of a single tick, the game checks whether dwarves are in deep water, this may be enough to train swimming.

I plan to test all this stuff when I have time, but if you (or anyone else) get to it first, post here and let me know .

One of us missed a key point, I think.  You can set up a flow without worrying about whether water actually moves from one tile to another.  It's how waterwheels over rivers work.  I guess it's not really a clever PPM, though, since the design is based on a glitch.

Sorry, I seem to be missing the point of this post.  Can you please elaborate?

One thing which I have done in the past to get a good non-interrupted flow is to use a PPM to power a pump or 2 which circulate water in a larger system which you use to power water-wheels.  Sort of a power multiplier system, albeit an overly complex dwarfy one.

Yep, that's how my current power plant operates.  In fact, I even used the exact term "power multiplier" in my notes while developing it .  I could never get the normal "pump water around a loop" system to work reliably, though, so I built a few multipliers based on the same diagonal-flow principle as the generator in my first post:

 
Pumps pump from the north.  Red arrows mark input axles; green arrows mark output axles.

assuming you did extra testing with the large scale power production, How does the system react if you mirror it, a waterwheel on each side, but keep the one pump? I'm not sure if both waterwheels will work with half the water going both ways each cycle or if they'll alternate...

It (somewhat mysteriously) works just fine if you mirror it.  The only problem is, once both waterwheels are in place, there's no way for a dwarf to get to the pump to start it.  You just have to add the second waterwheel after it's already running, and then be careful not to overload it so you never have to restart it.

Thats a desing pretty similar to the one I usualy go with for smaller amouths of power required, though mine is slightly smaller. Like this:

1st  2nd

####  ####
#77#  # w#
##7#  #PW#
#7##  +pw+
#R##  +h++
####  ++++
Where # are walls, + is floors, R is water covered ramp, 7 is 7/7water, H is a floor hatch, P is a pump, W is waterwheel and where the capital letters indicate an impassable building tile. The pump pumps to the north.

It lags minimally, can have another waterwheel without losing power or stability, and is easy to set up and connect to power.

Great - this is the kind of thing I was hoping for when I requested "clever perpetual motion designs!"

It looks like your generator and mine work pretty much the same way, though I had never really considered using the impassable square of the waterwheel as part of the containment for the pump's output.

Have you checked frame-by-frame to see if the power output is consistent?  I would be a little surprised if it was, since this similar design I tested loses power for about one tick in 20:

(pumps from north to south)
Losing power occasionally isn't much of a problem for running pumps, but for millstones, losing power for even 1 tick will cancel all the jobs.

I've come up with a design for a perpetual motion machine which I haven't seen used before:


The left side shows the upper layer; the right side shows the lower.
[Edit: The pump pumps water from the north]

After building this, fill the lower level to exactly 7/7 and wait for the top level to dry out (so no water will enter the system once it's been started).  Have a dwarf run the pump manually, and it should start producing power immediately.  This design produces 100 power and consumes 25 to keep itself running, so its net power output is 75.  The power output seems to be reliable; I checked every tick for 1,000 ticks and it never stopped running.

This machine has some interesting properties:

• Once it starts running, the pump's input tile always appears to be empty, while the output tile and the other tiles on the lower level always appear to be at 7/7.  Despite the apparent lack of motion, there is (almost) always flow in the two tiles below the waterwheel.  (Testing a similar design with only one tile beneath the waterwheel showed that a single tile will lose flow for one out of every 10-30 ticks.  I have never seen the waterwheel lose power with two tiles beneath it, though I'm not sure why this should be the case.)
• I currently believe that water will never evaporate from this system, which should be useful for low-water maps.  Testing shows that when water spreads from a 7/7 to a 0/7, the source becomes 3/7 and the destination becomes 4/7.  Since no tile is at 1/7 even temporarily, water should be unable to evaporate.
• This machine produces an extremely small amount of lag.  Running a single instance showed no significant drop in framerate (Pentium 4 3.2GHz; 32 FPS idle).  Running six machines using similar designs caused the framerate to drop by only 1-2 FPS.

As of 2 Mid-Spring, 47, my fort's power plant is using similar devices to produce 597 net power from a 15x15 room, set up in such a way that it will never need to be restarted even if the output is overloaded.   I also have two replacement designs to test: one based entirely on tested principles which produces 964 net power, and another based on one untested principle which outputs 1186 net power.  After I test these, I plan to post them here (assuming they work).

If you have any questions, comments, or clever perpetual motion designs, please let me know!