NymoLabs NBS-6040

About the Machine

The NBS-6040 is NymoLabs' compact router, with a 610 x 410 x 120 mm working area, a 710W stepless spindle (7,000-30,000 RPM), NEMA23 steppers, and linear rails with ball screws on every axis. It runs on open-source GRBL v1.1 with a 2.8 inch TFT touchscreen offline controller.

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 NBS-6040's stepless spindle runs 7,000 to 30,000 RPM, covering the full range of the chart, on NEMA23 steppers with linear rails and ball screws on every axis. That's a rigid setup for a compact machine: it can take a confident pass, but depth still comes down to matching your bit and material to the spindle's torque at that speed. Push too deep and the bit deflects and chatters, leaving scalloped edges, or it rubs instead of cutting and burns the material. Dial the spindle knob to the chart's recommended RPM for your bit and material, and build up your depth from there. 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, well within this spindle's 7,000-30,000 RPM range, so dial the knob 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.