I purchased a mist coolant block and nozzle (https://www.amazon.com/gp/product/B07HT1Y4BK), which I attached to the laser mounting screw holes, and used isopropyl alcohol (IPA) as my coolant/lubricant. While it primarily functions as a coolant, I like to think it provides some degree of lubrication as well.
The brass blanks were sourced from Send Cut Send (highly recommended). I secured them into a jig made from a scrap piece of wood, using a combination of blue tape and super glue. As long as I didn’t flood the piece with too much IPA and kept it to a barely noticeable “fog,” the tape and glue did an excellent job of holding the brass firmly to the MDF jig.
One of the advantages of using IPA is that it evaporates extremely quickly and doesn’t damage the wooden jig. By keeping the airflow at about 20-25 psi, I found it was enough to blow the brass chips clear of the bit.
The downside, though, is that the brass chips still get EVERYWHERE. Even with a dust boot and the misting nozzle working together, tiny pieces of brass seemed to fly into every corner! I had to be meticulous about vacuuming and cleaning up after each carving, and often during the carving process as well. Despite my efforts, I still ended up with brass splinters (ouch!) for days after, even when I thought I had thoroughly cleaned everything up.
Given the constant cleanup required and the fact that I was working on extremely detailed 3D carvings on relatively small pieces (~4-inch tall blanks), I’ve decided to scale back on these projects. Mass production of these intricate 3D carvings is simply too time-consuming and prone to scratches caused by the bit and/or chips getting in the way, so I’ll likely only do them for special occasions moving forward.
I hope this post helps someone considering brass carving! Photos, videos, and details on feeds and speeds to follow below.
Toolpaths:
3D Roughing 1
Powertec 1/8" 2FL Up Cut End Mill
1 mm Boundary Offset
0.5 mm Machining Allowance
3D Raster mode
Avoid machine areas: checked
Raster angle: 0 degrees
18,000 RPM
750 mm/min
750 mm/min plunge
40% stepover
0.0295 INCHES pass depth
3D Roughing 2
BitsBits 4TEB10-062-2FL - 1/16" Tip 5° Tapered Ball Nose
1 mm Boundary Offset
0.1 mm Machining Allowance
3D Raster mode
Avoid machine areas: checked
Raster angle: 45 degrees
16,000 RPM
2000 mm/min
1000 mm/min plunge
8% stepover
0.025 INCHES pass depth
3D Finish
Lakeshore Carbide 020ENG14-20DG-DE-N3 (20.0°, Tip 0.508mm - 6.35 mm)
1 mm Boundary Offset
3D Raster mode
Raster angle: 0 degrees
18,000 RPM
2000 mm/min
2000 mm/min plunge
8% stepover
