Can you use redstone repeaters to try and make it work?
Err... let me explain.
Assume a mere 4-block high elevator of sticky pistons (which of course extends to 8 meters). We'll call activating the bottom piston "+1", the one above that "+2", etc (accordingly, "-1" and "-2" would be removal of power). To fully raise the 4-piston elevator, the required redstone activation sequence is simple: +1, +3, +5, +7.
However, due to the way sticky pistons aren't sticky unless they're actively retracting, lowering the elevator is considerably more complex, since a retracting piston can only pull a single block. Even if that block is a retracted sticky piston, whatever
it's "stuck" to will not come along. Therefore, to retract the elevator you'd need to do as follows: -7, -5, -3, +4, -4, -1, +2, -2, +3, -3:
T = an extended piston arm
U = an extended piston base
O = a retracted piston
8: T
7: U -7 O
6: T T O O O
5: U U -5 O T O O O O O
4: T T T O +4 U -4 O O O T O
3: U U U -3 O O O T O +3 U -3 O
2: T T T T T T O +2 U -2 O O O
1: U U U U U U -1 O O O O O
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If you can figure out how to program
that sequence in redstone (not to mention the required sequence for a 12-piston elevator), please speak up.
