FoxAlien 4040-XE

About the Machine

FoxAlien no longer sells this model new, but owners can keep using it with Easel. The 4040-XE is a desktop CNC with a 400 x 400 x 65 mm active working area, a 300W spindle, and NEMA 23 stepper motors. It is based on GRBL and compatible with GRBL-control software. It assembles in 15-30 minutes.

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 4040-XE's 300W spindle cannot reach most of the speeds in the chart and loses torque fast below its top speed, so keep it near maximum and let the feed rate control the cut. Keep the RPM up for acrylic too, and speed up the feed if the edge starts to melt. Treat aluminum as light engraving only, with a single-flute bit. 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. A light machine like this one falls short of that bar, and the fix is simple: 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 the 300W spindle should stay near its own maximum instead; at 10,000 RPM 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 spindle audibly slows in the cut, 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.