Yes, to answer the title’s question, it wood. To be precise, this homework taught me how much effect a higher quality wood stock can have on the final product. I decided to apply myself this homework (kidding, of course – I apply myself on every homework) and do the advanced assignment, a CNC milling of something with multiple heights. I chose to mill out Mt. St. Helens due to my personal affinity for the site as I went to visit in summer 2024. I found out about 3/4 through my project that it was one of the pre-provided terrain STLs, so I felt slightly less special. I did choose a larger area than the provided STL though, so there’s that.
See, I promise I’m not boring!
While I don’t have any screenshots of my VCarve file and setup, we begin with the original stock I used. This is an old, cracked, block of pine that I selected simply because of its depth, as I wasn’t sure exactly how I wanted this to turn out and wanted to make sure we had enough height.
A face only a mother could love.
After initializing the Pro XXL with a 1/4″ end mill for the rough pass, I secured the block of wood down with double-sided tape and these green clamp things.
Safely (?) secured down.
It’s difficult to see in this photo, but the way I had to secure this down was not ideal. Because the base sheet of plywood I was using to secure the pine was wider than the wooden tracks on the bed, when I tightened the green clamps, it warped and lifted the block of wood sightly. It didn’t cause anything catastrophic during machining, but I fix this on the second time around.
Roughing pass complete.
You can see the warped plywood slightly more clearly on this photo. The roughing pass went well, though, and I’m getting excited! I won’t make you wait any longer, here’s the result of the first iteration of this piece.
The final product: 1/8″ ball nose mill.
However, there are a couple problems with this piece. For one, the tutorial failed to mention the option to add a margin of error – as it stood, I put in the exact dimensions of this block. Because I was unable to make it perfectly parallel with the bed rails, the mill did not reach the back corner. In addition, the cracks and imperfections in this wood unfortunately became more of a distraction than anything, and while I thought it would be cool to have the rings center on the mountain, it’s also a little distracting. Finally, we can use a much shorter block of wood for the next iteration. Thankfully, Prof. Bisesti was to the rescue!
Walnut it is!
This is a block of walnut that came from a desk that had been scrapped. I cut it to this size using the miter saw, and sanded all of the cheap finishing off of all sides (and generally cleaned it up).
Cleaned up and ready for the CNC mill!
This time, I cut down the baseplate of plywood to fit between the tracks of the bed. Although this did reduce the area of the piece in contact with double-sided tape, the fact that it didn’t warp likely made the connection stronger.
Halfway through the roughing pass.
One thing I did not expect was the messiness of the roughing pass as opposed to the first one. You can see in the above photo there are strings of walnut being made, as opposed to the sawdust you want to see. I believe this is because a) walnut is a harder wood than pine, and b) the 1/4″ endmill was likely getting dull. I wanted to make sure I got a great product out of this, so I cleaned it up as best I could between layers and made sure to select a brand-new 1/8″ ball mill for the finishing pass.
It feels like revealing some artifact from the ground
Milling complete!
As you can see, the changes I made to the file setup really helped: the mill cut all the way past the edges so there were no weird spots. Unfortunately, two screw holes I had seen in the bottom of the piece were long enough to make an appearance on the top surface. I filled these with super glue and sawdust as best I could. Then, I finished the piece with some very light sanding and tung oil.
Two coats of tung oil.
I am incredibly pleased with how this second unit came out, and I hope you are too. This is absolutely something that I see being taken with me when I graduate and being displayed in my apartment. The walnut is absolutely gorgeous, and I’m glad I got a second chance after that pine unit.
The bed of the Shapeoko cleaned up.
As always, here’s my clean workspace, and we can now go into cost breakdown.
Total Cost
Materials
Pine block: scrap wood, $0
Walnut: 1.8125″ x 4″ x 60″ = $57.03, so 5″ of this = $1.58
Tooling and Machine Time
Machine time: 5hr total @ $10/hr = $50
1/4″ carbide end mill: $15
1/8″ carbide ball end mill: $11
Labor
6h of work @ $10/hr = $60
Total: $137.58
This was probably the most fun I’ve had so far in this class, and it’s just a bonus that I got something really beautiful out of it.
