FoxAlien XE-Ultra

About the Machine

The FoxAlien XE-Ultra is the flagship large-format CNC with an 840 x 840 x 120 mm working area, 16mm (XY) and 12mm (Z) ball screws with HG-15 linear rails, and 60-86mm closed-loop stepper motors (2.6 N.m). Spindle and spoilboard are not included with the base 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 XE-Ultra ships without a spindle. Most owners install a 65mm trim router or FoxAlien's 1.5kW VFD spindle, and either one can hit every speed in the chart, so set your RPM straight from it. If plastic starts to smear, slow the spindle down or speed up the feed. 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. Few hobby machines check every one of those boxes, 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, and the bit maker's chart gives 0.025mm per tooth (0.0010 in). Feed = 16,000 x 0.025 x 2 = 800 mm/min (31 in/min), well under this machine's 5,000 mm/min (197 in/min) maximum. 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.