Machinist Apprentice | Copper Parts! | Day 23

Today I got to machine the 101 copper parts I mentioned previously. Unfortunately, since these are more detailed pieces, I am not able to show the entire piece and have to blur some parts out. But as you can see, they turned out nice!

In preparation for this part, I did some research on milling copper, and for the most part, a lot of people say it's one of the more delicate materials to cut as its got a gummy like consistency and can wad up on your tools. I also read that you want very sharp tools when cutting it to prevent the material from just being pushed rather than sliced through it. I also found that it's super shiny and picks up every little detail; even with the finished product, you can clearly see the path of the tools but can't feel any deviation in the finish. Because of this Wayne had me do a spiral toolpath in the little pocket on a ball endmill, he said if I used a flat or bullnose endmill and cleaned the bottom face unless I had the tools measured correctly, you would see a slight step between the endmills even if you couldn't feel it. I had to use a ball endmill to get the corner radius at the bottom of the pockets.

Overall it wasn't too difficult to program, and the entire machine time for ten parts (each about 1" square) was one and a half hours. I needed to make 20 of these, but the second set required a larger hole size, so instead of reprogramming the whole thing, Wayne just had me run the same program but switched out the drill bit. When I ran the second batch, I remembered a second before the tip of the drill hit the material that I forgot to set the tool height, and thankfully no harm was done. If I let it run, it would have rapid into the stock thinking the drill was shorter. 

After that I de-burred the parts and started threading the holes on one set, I ran out of time though and will have to pick up where I left off on Monday.