Vision VR48 4 Series, User Manual

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Example Jobs 281
© 2015 Vision Engraving and Routing Systems
7.4 Feeds and Speeds
The best way to obtain cutting speeds and feeds is by contacting the tool or material manufacturer.
Otherwise, determining the optimal cutting speed and feed rate for the project at hand requires some
research and experience. Researching your cutter or material will ultimately yield a chip load or a SFPM
(Surface Feet per Minute) value. These tool/material specific values can then be used in the following
calculations to determine the speed and feed rates for your job.
Speed equals the spindle speed in revolutions per minute (RPM).
SFPM equals the Surface Feet per Minute and is the speed at which the cutting edge of the tool moves
past the material. This value is tool and material dependent.
Diameter is the tool diameter.
Feed equals the linear feed of the tool through the material.
Chip Load equals the amount of material each cutting edge of the tool removes per revolution. This value
is tool dependent.
Speeds and feeds are often adjusted at the machine based on chip shape and size or the cutting sound.
For routing applications one should start off using the recommended chip load and RPM for the material
you are cutting. Increase the feed rate until the part finish starts to deteriorate or you risk moving the
part. From this point, decrease the feed rate by 10%. Next decrease your RPM until your surface finish
deteriorates, then increase your RPM until the finish is acceptable. These steps will yield the optimal
speed and feed rates and the largest chip possible. Take note of these values for future reference.
Factors that will affect your feed and speed values include:
Hardness of the material - Wood is the perfect example of this variable. A hard wood such as
oak will require a slower feed rate than pine.
Chip removal efficiency – A large nose cone and high volume vacuum will remove chips more
efficiently thus allowing for faster feed rates.
Size and Type of Cutter – A fine tipped cutter is more fragile and will require conservative feed
and speed rates.
Required Accuracy and Job Detail – products requiring fine detail or accuracy will require
slower feed rates to account for tool deformation.
Hold down method – The more securely a product is held down the more aggressive the feed
and speed rates can be.
Depth of cut - Shallow cuts can be made with faster feed rates.