You already said that a few posts ago I think. :P

Anyways, I thought you could, but I'm not perfect, haven't used JCS for ages. ^_^

There's another way though.

1. Put the crate on a speed block.
2. Put belts a few tiles below the speed block.
3. Do the thing with the TNT and stuff I explained some time ago.

If Birdy crushes the speed block (which I assume he can) the crate will fall down on the belts, gets carried to the TNT, explodes and frees the bird.