Millright CNC Mega V Pro

About the Machine

The Mega V Pro covers two sizes on one build: Standard at 19 x 19.6 x 6 in (494 x 500 x 152 mm, about 5.5 in gantry clearance) and XL at 35 x 35.4 x 6 in (888 x 900 x 152 mm, about 5.5 in gantry clearance). It runs a 2HP air-cooled ER20 spindle (6,000 to 24,000 RPM), closed-loop stepper motors with encoders on rack-and-pinion X/Y drive and a trapezoidal lead screw Z axis, and MGN15 linear rails on every axis. It comes pre-assembled and pre-tested: mount the control stand, plug it in, and start machining.

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 Mega V Pro's 2HP air-cooled spindle runs 6,000 to 24,000 RPM, well above most of the chart below, so leave it at the chart's recommended speed and control the cut with feed rate. Its closed-loop steppers with encoders, rack-and-pinion X/Y drive, and MGN15 linear rails on every axis are built for real rigidity. 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, and the Mega V Pro is built to that bar. Even so, push a pass past what the flute geometry and material can clear and it will deflect and chatter, leaving scalloped edges, or rub instead of cutting and burn 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, well within this spindle's 6,000 to 24,000 RPM range, so run it at 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.