Large-format CNC in three cut areas with a Buildbotics controller and open-loop steppers
Use with Easel Pro →
Onefinity no longer sells this model, but it remains fully supported in Easel. The Pro Series was sold in three cut areas: Woodworker at 32 1/4in x 32 1/4in x 5 1/4in, Journeyman at 48 1/4in x 32 1/4in x 5 1/4in, and Foreman at 48 1/4in x 48 1/4in x 5 1/4in. All three drove their axes on open-loop high-torque steppers over 16mm ball screws on X and Y and a 12mm ball screw on Z, ran a BB Buildbotics controller, and shipped with no spindle included; Onefinity recommended a Makita RT0701C router or its optional Redline 80mm spindle kit.
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 Pro Series doesn't ship with a spindle: Onefinity's page points to a Makita router or its own optional Redline spindle kit, so check whichever unit you use for its actual RPM range. The machine itself runs open-loop steppers, not closed-loop, on 16mm ball screws with a 12mm screw on Z, a step down in rigidity from the closed-loop Elite Series. 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. Open-loop steppers can skip a step under load without you knowing it, so lean conservative on depth per pass rather than pushing toward full bit diameter. 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; since the Pro Series doesn't include a spindle, check your own router or spindle's plate for its actual maximum and cap the RPM there if it's lower. 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.
The Onefinity Pro Series runs a Buildbotics controller, not GRBL or FluidNC, so Easel's live Driver and Rapid Connect do not drive this machine directly. Instead, set up a Non-GRBL Machine Profile for it in Easel, design your project as usual, and use Project > Download G-code to save a finished .nc file. Get that file onto the Buildbotics controller over its Ethernet or WiFi network/web interface, or by USB drive since the machine only reads USB as storage rather than streaming G-code live over the cable. From there, load the file in the Buildbotics web UI and run the job from the controller's own screen.
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