What are Feeds and Speeds for CNC Machines?

What are Feeds and Speeds for CNC?

“Feeds and speeds” is generally refer to “feed rate”, “slew rate”, “plunge rate” and “spindle rpm”.
The feed rate represents how fast the machine moves the router bit though the material when cutting and is critical to get right for leaving a good quality cut edge.

Slew rate is the travelling speed that the machine moves when above the material and is travelling between cuts. This is normally set to as high level as possible in order to reduce cycle times.

Plunge rate is the speed at which the router bit is driven down into the material when starting a cut and will vary depending on the bit used and the material being processed. It is important not to plunge too fast as it is easy to damage the tip of the cutter during this operation.

The spindle speed in rpm should be set to a value that is appropriate for the tool being used and the material being processed. Feed rate and spindle speed are inter-related. Sometimes it is possible to cut at a faster feed rate by increasing the spindle rpm. Similarly, if you cut at a too low feed rate or with a too high spindle rpm, there is a risk of overheating the router bit and potentially burning or melting the workpiece.

For foam cutting, 4000-7000rpm is usually recommended for foam milling cutters. It is good to the machine and foam cutters, also can get good surface finish. The feed rate depends on the foam cutter size, material hardness, and rough cutting or finish cutting. 

When medium density foam cutting, for rough cutting you can set the rpm at 6000, cutting depth 30-50mm one time, cutting rate at 5000-6000mm/min. 
If needed for finish cutting, you can set the rpm at about 7000rpm, cutting depth 10-20mm or less, cutting rate at 6000-8000mm/min.

Big cutter had better set the rpm lower, about 4000-5000rpm.

RicoCNC supplies a range of cnc tools, routing bits, and owns many years experience in CNC industries, welcome to contact us.