This week, we learned how to process basic vectors and create a file that can be carved out using the CNC machine. It was pretty fun how to use carbide create, a very straight forward application, and how to function the CNC machine.
Process:
The first step was choosing, designing, and making the file. I decided that I wanted to cut out a mini winnie the pooh from the wood, since he was my childhood best friend. I found an svg. file online that I edited using adobe illustrator to clean up some of the lines. Then, I followed the instructions to upload and edit the svg. file on carbide create. I experimented a little with different results that it can produce (the show stimulation function was extremely useful) and decided on what my final file would be, consisting of two layers of different depths for more detail.
I had this file prepared before my CNC machining tutorial, and luckily everything worked perfectly during the tutorial. I had no issues loading the file into the pc at the smaller CNC machine and entering the thickness or orienting my piece. I made sure to follow the steps of double-side-taping the base piece, securing the wood, probing, and pressing start. I made sure to pause it halfway and vacuum it so the process is more visible halfway through the cut, which took 35 minutes in total. I also made sure to vacuum everything and leave a clean workspace for the next user. Due to the piece of wood being slightly uneven, there was an area that wasn’t cut through completely, but the remining wood was so thin that the piece was easily broken out.
I went in at a time during the week to finish the cut for the other one. I followed the exact same steps and made sure to measure and reset the thickness of the wood. This time, nothing went wrong and all sides of the piece were cut out perfectly, but there were just a large amount of wood debris, which is probably different for each different piece of wood and the direction of the wood grain.
The next steps would be post-processing. This is when I realized that it was going to take a good amount of work because of the excess debris on the interior edges due to the fact that I had another inner layer. Sanding these two pieces took a good two hours, but I’m glad that they turned out pretty well in the end!
The next step was finishing with wood stain. I chose the dark walnut wood stain from the blue stains basket on our table for the nice color. Before I did my stair, I did a test on a piece of scrap wood to test out the color, which looked nice and light, giving the wood only a slight tint of color. I followed the instructions, which were the same processes I used to apply the test stain on the scrap wood, but the results were very bad. First of all, the colors were much darker, even if i used a towel to apply the stain and wiped it off immediately after I saw the effects of the color. Secondly, the lines of wood grain on both of my pieces started expanding and becoming spiky. The texture changed from my smooth, sanded piece to an extremely rough piece that seems unprocessed at all. I checked the description of the wood stain again and it says that i can be applied to raw wood and all the instructions and steps to using it had been followed, so I am very confused why it made my piece of wood swell. After some more questioning, I concluded that maybe it was because it is a water based wood stain.
I decided to at least finish it first because I was rushing to something afterwards, so I sprayed a layer of matt finish first. I then came back the next day to do what I could with the sides and sand as much as I can to make it smooth. After that, I sprayed another layer of matt finish.
Now we have the final results, which is a rescued winnie the pooh!
Cleaned workspace:
Cost Estimates:
- Wood 3/4 inch: $12.48 (lowe’s)
- Dark Walnut Wood Stain: $15.97/can * 1/10 can = $1.60 (amazon)
- Clear Matt Finish Spray Paint: $5.98/can * 1/10 can = $0.60 (home depot)
- Sand Paper: $4.50 approximately (amazon)
- CNC Machine Rental: $90/hour * 1.5 hours = $135 (practical machinist)
- Labor as a Design Engineer: $31/hour x 4.5 hours = $139.50 (zip recruiter)
Total: $293.68 ($146.84 per piece)
Reflection:
I think this project would be a lot easier and have a much lower final cost if the machinery was available and also if the stain didn’t go wrong. The extra hour could be completely avoided if I decided to do a beeswax finish or something that’s oil based and bonds with my pieces of wood better.
