I just made a few designs for the most efficient wood harvesting possible. It works through block detectors and pistons placed on one side of the farm, which push the trees as soon as they grow. From there the trees all stack up until a row is full, then a grid of pistons pushes the logs and clears the way for more. Here's a video:
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PearSquirrel's Youtube Channel
I mainly create redstone contraptions including but not limited to minecart stations, door designs, and automatic farms. Feel free to check me out!