How to Build an Automatic Tree Farm with the Block Breaker and Deployer

Setting Up the Breaker

Place a Block Breaker facing the block you want to harvest. It needs a redstone pulse to activate, so run a clock or a lever into its back/side. The breaker will pop the block in front of it and drop the item, so put a chest or Pneumatic Tube behind it to collect output. For a tree farm, position the breaker at trunk height so it removes the log column when pulsed repeatedly.

Replanting with the Deployer

A Deployer acts like a fake player: it can right-click with whatever item you insert into it. Put saplings in the Deployer and aim it at the dirt/grass block where you want the tree. Pulse it after the breaker finishes so the sapling is replanted. The Deployer also uses a small internal buffer, so keep it stocked via a tube or hopper.

Timing the Cycle

If you use Frames and a Frame Motor, you can move the whole breaker/deployer rig along a row of trees instead of building one per tree. Keep the Deployer's sapling supply topped up or the farm stalls after the first harvest.