Okies... been having a thought, but don't have enough know-how myself to pull it off.
I want to create an AUTOMATED obsidian farm to train my military, and to generate obsidian goods/blocks/etc.
The way I am imagining this being set up is to have a water tower on one end, and a magma tower on the other. The area between them is where the actual obsidianification would be done, and would be a 1 z-level pit 32x10 with three 10x10 retracting bridges centered within it. The remaining 2 spaces would be left, one on either end of the long pit, to house pressure plates to determine depth of magma (on the water tower side) or water (on the magma tower side). The bridges would cover a pit that is 30 long x 8 wide x n levels deep, the remaining 2 spaces (from the upper pit; 32 tiles - 30 tiles for the lower pit) would be left as two long strips of 1 tile each all the way down the side of the pit, to provide seating for the bridges.
How I would like to see this working is that a dwarf up top pulls a lever, and the machine starts up. First, magma is pumped out from the tower to the top of the bridges. When the pressure plates on the water tower end determine that they are all covered in 2 z-levels of magma (to prevent evaporation), the bridges are triggered, and drop the magma into the bottom z-level of the pit. After the 100 tick delay (which conveniently would allow for the remaining magma on the pressure plate squares to drain/evaporate), the bridges close again, and the water pumps perform the exact same routine.
Obviously, once water hits magma at the bottom of the pit, obsidian will form.... However, this is not !!SCIENCE!! enough. This entire process needs to repeat itself automatically until all z-levels of the pit are filled with obsidian, and then STOP so it can be mined and happiness can ensue.
So far, until I can get a decent idea as to how to proceed, this is all on paper...I am having a few difficulties with this design.
1) I can see how to trigger the pressure plates once they are all covered with magma/water... simply attach each pressure plate to a gear, and attach the gears to each other sequentially.. apply power to one end, and the power will not come out the other until all of the pressure plates are simultaneously active. This would work fine for pump control, as the pumps require power to activate...does it still work for bridges? If not, how does one trigger a bridge with an AND gate?
2) I am looking up timing controls now to compensate for the 100 tick delay... this way, when the pressure plates empty off (due to the bridge dumping), I can time when to activate the other set of pumps, and accurately assume that the bridges have closed. Or am I over-thinking, and there is some way of determining directly that the bridges have closed?
3) I am unsure how to switch power from one system (like magma) to the other (like water)... in other words, once the magma side has done its thing, and the 100 tick delay has expired, and the bridges have closed, how do I then trigger the water side rather than the magma?
4) How do I get the entire process to shut down when complete? My initial thought is to have a separate pressure plate up top (probably on the side of the bridge pit, and centered between the towers). This one (two actually, water and magma) would trigger if covered by (2/7 magma OR 2/7 water) AND bridges have been open for xx ticks. This would require a separate timing mechanism, at least.
5) Last but not least... if I succeed at getting this entire system automated, and get a dwarf to throw the switch, then that switch will be in the same position when all is said and done... (ex. He turns it on, it is still 'ON' when process completes)... this might lead to issues with repeating the process. Is there a way to trigger the switch to turn itself off (somehow, I strongly doubt this)? Is there a way to have the system trigger whenever the switch is thrown, regardless of its actual position? Would I simply have to have the dwarf thrown the switch twice in succession every time he started it ('OFF' then back to 'ON')??
I would really love to build this thing as my introduction to serious dwarf mechanics... but lost as to where to start with it. Building this system to work with two switches (water and magma - color coded and such) seems far easier to do, but far less worthwhile.
Any assistance would be greatly appreciated.