CNC4Newbie Upshot Mill

About the Machine

The Upshot Mill covers multiple kit sizes on one product page (2424, 4824, 4836, 4848, and 4896 in Easel's menu; CNC4Newbie's page also lists a 3636 size not in Easel's menu). CNC4Newbie states a work area up to 50 x 98 in (max 68 x 110 in footprint, 8in clearance below the gantry) but does not publish a per-size breakdown table. It runs rack-and-pinion drive on X/Y and an HD ballscrew-driven Z axis with 8in of travel, 15mm square linear bearings on every axis, and can take a round- or square-body spindle up to 2.2kW, not included; mount options run from 65mm up to 89mm.

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 Upshot Mill ships without a spindle, so its top RPM depends on whatever unit you mount, up to 2.2kW, check that unit's own rating plate against the chart rather than assuming a number. Its rack-and-pinion X/Y drive, HD ballscrew-driven Z axis with 8in of travel, and 15mm square linear bearings 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. With a suitable spindle mounted, the Upshot Mill can handle solid depth per pass, but still build up gradually. 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. This machine ships without a spindle, so check the RPM rating on whatever you mount, up to 2.2kW, and use its actual number if it differs from 16,000. With the bit maker's 0.025mm per tooth (0.0010 in), at 16,000 RPM: 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.