And now, the rest of the story. . .

I thought that I would take a moment to talk about the rest of the pieces of the door/combination lock I showed in the previous post.  Other elements I put in the device are a sound emitter, and the door itself.  Both of them are activated when the two-way switches are set correctly and the blocks in the lock are extended fully.  If you take a close look at the top of the door, and the last block in the lock (hey, that rhymes), you can see what I had to do to make sure the door only slid up. 

I added a magnetic key on the door, matched with a magnetic switch at the top of the door pocket.  When the door pulls all the way up, it activates the switch, which triggers…wait for it…wait for it…the last block in the lock which is made out of dissolving material.  When the block, which holds the magnetic key that activates the door and sound emitter, dissolves, the magnetic key is destroyed and the magnetic switch that turned on the door and sound emitter shuts off. 

All that is left to do is to go back and build all of this using grids.  That will ensure that everything lines up nicely, and that I use the minimal amount of materials to build it.  Once that is done I can save it as an object and prepare to place it in the final level.