You will always need some MFEs. You can't join current otherwise.
Switch cables combine current more predictably than MFEs, and are less expensive. 5 inputs, 1 output, stackable without possible weird feedback loops.
MFEs will send current upward
if there is something that accepts it. Otherwise it does down. I'm not sure a cable counts as an acceptor, because it's not a consumer.
So for a vertical hoover dam, I imagine a column of switch cables with 4 water generators hung on every second cable, and water source blocks on top of each generator. Current will combine and flow down. You should find out today's limit on cable length before you get losses, and put in a single MFE at that point, counting from the top. This probably means a jog in the cable to avoid a current loop, because the MFE will try to send current back up if you send current directly down into it. So your switch cable column feeds down into a single normal cable which feeds horizontally into a MFE, which then feeds down and continues the column. If you want to go that high.
This could be quite a pretty construction. It'll look like a fountain. Position a few glass and obsidian blocks around it, maybe some nice colors of wool inside the flow, a brick pool wall, make something useful
and nice to look at.
Hmm. Now I want to try one. Comments, anyone? Refinements?
And remember, while you are mining out that space, you may well encounter more than enough tin and copper for all your needs. Remember, those two can be combined in a certain way to make iron, which was already posted.
8 to 10 tin
and 8 to 10 copper for 1 iron? Thanx but nothanx. Autominers FTW. I've been running 4, 2 at a time off 5 solar panels + occasional charcoal-fired generators, and I'm about to upgrade to blocks of 8 running off nuclear. 8 running while I collect ore and spoil, place the next 8, and run more HV cable. I'm getting really good results.
Always do large-scale mining in the southwest quadrant, i.e. where X is positive and Z is positive on the F3 display. There's a bug in the ore placement algorithm. (It floors when it should round to zero.)
When retracting drilling pipe, I like to put a single torch in the pipe/fill box, then once that's placed, I put in a feather or porkchop or something so that nothing gets filled in as the pipe retracts. When the pipe is up and I come by to check it, I send just one pipe down, then use a glass block as retraction fill. I get a nice shaft with a torch 60-odd levels down. Pretty!
The glass block keeps the miner from falling down the shaft when I wrench it.Tired. Rambling.
Edit:
Recipe book crashed me. :\ I haven't opened Minecraft yet, but I hope it didn't ruin the work on my house.
I think someone said it had troubles with TooManyItems.
For serious? Recipe Book is like the least intrusive mod
ever. I've got it running with TMI and 5 other mods, fine. (1.4, not the current 1.4_01.) It doesn't have class file collisions with TMI, and it's by the ModLoader guy, it's gotta be good.