How to remove a smaller cube from the end of a wooden beam

Question

I have this wooden beam 12cm x 12cm. I need to remove a 10cm x 10cm x 6cm cube from it. What's the easiest way to approach this? I don't mind buying machinery for it if that makes the task any easier.

Update: I want to end up with the beam and I don't care about the cube. A comment suggested that it might not be obvious.

Answer 1

I ended up doing the job with a jigsaw and a drill. Jigsaw saws are available in several sizes. One of them went exactly 10cm deep. Of course it would bang into the wood if I would saw the 3 plains. To minimize the banging I drilled 3 holes along the end of those plains. I hope these pictures help to make sense out of this.

Keep the jigsaw firm and progress it slowly forward. The drilled holes might be off a bit and the saw will bang in the wood as it progresses. Need to keep the jigsaw pressed against the wood to absorb the mild blows.

Here's the end result after shaving a bit with a wood file.

Oh and the 2cm that's left is strong enough. That won't break easily. Not with your bare hands or fingers at least as someone suggested.

This method will probably not work in hardwood.

Answer 2

Here are two approaches:

1. Saw and chisels. This is the easiest and least expensive approach. A sharp hand saw will make short work of cutting into the wood on all three faces cutting a triangular section on each face. Clearly you cannot saw any deeper without overcutting the outer lines. Next, draw a line across the top diagonally from top left corner to the top right corner, securely clamp the block to solid work surface and remove the outer section of the clock which has had its inner face fully sawcut using a chisel starting at on the top line and working down. This block will come free quickly since you are using the chisel to split the wood along its grain much as an ax splits firewood. Now you can use a 1" +/- chisel and mallet working along the sawn inner faces to cut out the remainder of the wood. Take the wood out in small depth increments, cutting across the grain several mm using the sawn face of the remaining wood as a guide and then with the grain to pry the cut section out. Work methodically and you will soon have the full volume removed.
2. Router with a long bit. This option will require securing the wood post to a solid bench such that the top is flush with the top of the bench. You will then mount two wood rails to the bench surface to serve as guides so that the router base plate prevented from penetrating into the wood beyond the width and depth of the void are desired. Begin by removing a shallow section (5mm) with the router and use increasingly deeper bit settings until you have desired depth.

The saw and chisel is the quicker/easier method especially in softwoods like in your picture. The router can be dangerous for a beginner so make sure you understand how to use it properly before making this type of attempt. As with all woodwork projects, your first attempt may not be as successful as you hoped for. Practice improves everything.

Answer 3

I would use an oscillating multi-tool.

Use a technique similar to this- https://www.youtube.com/watch?v=qwpt1ghzdNg Basically removing a small layer (1/2 inch) at a time till your at the required depth.

Answer 4

Along the lines of the comment left by Graphus, I would tend to try to accomplish this a different way, with an eye toward the strength of the piece. Instead of cutting out a cube, start with a 10 cm x 10 cm post of the appropriate height. Then glue two 2 cm boards to adjacent faces of the post. This will let you pick boards where the direction of the grain is much stronger than what will be left if you make the cuts as shown in your picture.