Sainsmart Genmitsu 3020-PRO Ultra

About the Machine

The Genmitsu 3020-PRO Ultra has a 300 x 205 x 78 mm working area, a 710W spindle (65mm diameter) with an adjustable 6,500 to 30,000 RPM range, and 60mm NEMA17 stepper motors (7.3 Nm torque).

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 3020-PRO Ultra's spindle adjusts from 6,500 to 30,000 RPM, which covers the entire chart, so dial it to whatever the chart recommends for the material and bit rather than leaving it pinned at max. 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 machine has real spindle power, but its drive is dual linear rails with a lead screw on X and polished rods on Y/Z rather than ball screws throughout, so it falls short of that top rigidity tier. Keep passes moderate rather than pushing full bit-width depth. 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, and this spindle's adjustable range covers that, so dial it to 16,000. 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.