Whittle CNC Router

About the Machine

THE WhittleCNC is a compact kit CNC, with a 228 x 356 x 50mm (9 x 14 x 2 in) working area, built around a custom stepper shield (EasyDriver drivers) and a CH340 USB connection. It ships without a spindle: an optional 'With Router' 110v rotary tool variant is available, or you supply your own compatible rotary tool. Whittle CNC does not state a drive system (belts, screws, or rails) for this machine.

Cut Settings on this Machine

Every cut starts with one formula: Feed Rate = Spindle Speed (RPM) x Chip Load x Number of Cutting Edges (flutes). Chip load is the thickness of material each cutting edge removes in one revolution of the bit. This number comes from the manufacturer of the bit, which publishes a chip-load chart for each bit diameter and material. Look up your exact bit and material, start from the middle of the published range, and you have the third number in the formula. The chart below shows the recommended spindle speed for each material and bit type.

THE WhittleCNC ships without a fixed spindle: you either add the optional 110v rotary tool variant or supply your own compatible rotary tool, so its actual RPM depends on what you install. Check the plate on your own tool before you start, since the chart's numbers only apply if your tool can actually reach them. Depth per pass is where a light kit machine like this one matters most: a truly rigid machine with a powerful spindle can cut as deep as the bit is wide in a single pass, but that takes real spindle torque, a drive train and clamps that hold firm, a gantry that will not flex, and enough mass to soak up vibration. This machine's small frame and user-supplied rotary tool put it well short of that bar, so take shallow passes. Push too deep and the bit deflects and chatters, leaving scalloped edges, or it rubs instead of cutting and burns the material. The fastest way to dial in a cut is to see what has already worked for other people.

Worked example for feed rate: 1/8in (3.175mm) two-flute solid carbide end mill in hard wood. The chart says 16,000 RPM. THE WhittleCNC doesn't ship with a fixed spindle, so check the plate on the rotary tool you install and use its actual top speed in place of 16,000 if it is lower. With the bit maker's 0.025mm per tooth (0.0010 in): 16,000 x 0.025 x 2 = 800 mm/min (31 in/min) feed. For depth per pass, start shallow and check Community Cut Settings in Easel for what works on this machine. If the cut sounds strained, reduce the depth, not the feed. Slowing the feed below the chip load makes the bit rub instead of cut.

Community Cut Settings shows the spindle speed, feed rate, and depth per pass other makers actually run for your machine, material, and bit.