2. Tips to Get the Best Results from Machining CNC Acrylic
Here are some tips on how to approach the CNC cutting process done over acrylic:
2.1 Secure Your Material
Properly secure the acrylic polymer sheet on the worktable using clamps, wise, or other methods. Acrylic is prone to chatter, so you should ensure that there is no way workpiece vibration may arise during machining. Overuse, the quality of cutting and especially of surface finish may heavily deteriorate.
2.2. Use the Right Bits and Ramps
Ensure that you are machining acrylic with the right drill bit. Carbide is a great choice. Besides, many manufacturers prefer a 1/4-inch solid carbide O-flute designed for acrylic cutting and drilling specifically. You may also look for other options intended for acrylic cutting.
Make sure the bits are sharp since dull bits cannot create edges that are clean enough. Acrylic material is sensitive to worn tooling, and you may notice lots of imperfections on the workpieces if cutters are inadequate.
Another piece of advice is to use a ramp along with your bit. It significantly lowers the risk of a drill bit damaging the acrylic. Use a smooth ramp between 1 to 3 inches for the highest quality finish.
2.3. Set the Right Feed Rate
Choosing the correct feed rate and speed rate is of equal importance. Higher feed will prevent acrylic from melting. But be careful since extreme external stresses may cause an acrylic component to break. Higher feeds can also disclose parts or leave blemishes. At the same time, slow feeds lead to unfinished surfaces. Take a couple of attempts to find an optimal setting.
2.4. Use the Correct Revolution Per Minute (RPM)
As for speed rates, you need to correlate them with your feed set. The type of acrylic you use will heavily impact the settings. Faster RPM, as a rule, requires an increase in the feed rate to prevent the melting of the material because of the increased friction impact.
2.5. Set the Pass Depth at the Correct Inch
Cutting depth is another important consideration. For most materials, it should be half the diameter of the bit. Alternatively, some materials, including acrylic, may require a pass depth of 0.0625″ inches for optimal outcomes. Once again, you may need several tries to figure out the suitable value.
2.6. Cut Direction is Important
The anticlockwise direction of cutting is hard to recommend. On the other hand, conventional or clockwise directions are known for producing the best outcomes. Just remember that they should be picked with the direction of the rotating cutter in mind.