Sainsmart Cubiko CNC Router

About the Machine

The Cubiko CNC Router has a 150 x 110 x 40 mm working area (58 mm Z gantry clearance), a 75W spindle (10,000 RPM max), and NEMA 17 stepper motors on an 8mm lead screw drive.

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 Cubiko's spindle tops out at 10,000 RPM, below most of the chart. It's a small 75W spindle that loses torque near the top of its range, so leave it near 10,000 for everything and control the cut with feed rate instead. If acrylic starts to melt, speed the feed up rather than slowing the spindle, and skip aluminum on this spindle except for light engraving. Depth per pass is where the machine itself matters. 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 is a small desktop machine on a lead screw drive, well short of that bar, so take shallower 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, but this spindle tops out at 10,000 RPM, so run 10,000. With the bit maker's 0.025mm per tooth (0.0010 in): 10,000 x 0.025 x 2 = 500 mm/min (20 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.