Minecraft - Secret passage behind staircase?

I have a hidden fortress built, and near the entry, you move down a staircase into the main reception area. At the bottom, I have the 2 middle steps and the row just above it also has 2 middle steps that are supposed to drop down and reveal a hidden passage behind it.

Here's my logic:

1. Flip the switch(lever)
2. First 2 pistons go down taking along the bottom 2 steps
3. Second 2 pistons go down, taking along the second pair of steps.
4. (This is where the problem is found) The last 2 pistons go down to drag down the second set of pistons which would also drag down the steps to an equal level as the bottom 2.

Now the problem there is it either drags down the 2 sticky pistons holding the steps without bringing the steps along, or it just doesn't drag anything at all...

Same problem goes for the other way around, it doesn't want to place the steps in the right places.

The area I have to make this work in is a limited 10(length)x7(width)x4(height) room.

Any solution would be welcomed, if needed, I'll e-mail you the world so you can view my current taking and maybe find a solution.

EDIT: Links to screenshots

The lever to "open" the staircase

The staircase not opening so well, the rear 2 steps should drop 1 block lower

The circuitry beneath the steps

-
Could you make screenshots this would help a lot in pinpointing the problem. – Andalur Dec 7 '12 at 23:10
Last I knew, you can't string together sticky pistons to pull each other while remaining engaged with another block. Have you tried shifting the stairs off to the side instead of down? – Luck Dec 7 '12 at 23:41
Sadly, there is no room to the sides and have to drag them down... – Hurly Dec 7 '12 at 23:47
I can't tell from the screenshots, did you implement proper double extender logic? Pulling a sticky piston down doesn't also pull the block above it. – MBraedley Dec 8 '12 at 2:18
@Hurly Since that seems to be the answer, can you post it as one? It's AOK to post answers to your own questions, here. Share your modified design with us so we can all use it! :) – SevenSidedDie Dec 11 '12 at 5:46

1 Answer

One construction I found that works reasonably well is to have the top staircase pull back instead of down, like so:

(Cutaway view)

It's probably not as elegant as yours looks like it's aiming for, and it has to have a slightly sunken passageway, but hope that helps!

-
+1 I've used this design quite often. – gnovice Dec 13 '12 at 19:51
Sorry for taking so long to actually read this one, I eventually did sort it out and have it working well thanks to the double extender logic and a bit of adapting. but this would work just as well for having a lair that goes deeper instead of having a normal straight corridor behind a staircase. – Hurly May 18 '13 at 14:08