Two Trees TTC-H40

About the Machine

The TTC-H40 is Two Trees' large-format router, with a 1000 x 1000 x 100mm (39.4 x 39.4 x 4 in) working area. It ships with a 500W spindle stated to run 8,000 to 30,000 RPM depending on installation, and it moves on trapezoidal lead screws on its X and Y axes and linear rails on the Z axis, controlled by GRBL.

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.

Two Trees states the TTC-H40's 500W spindle runs 8,000 to 30,000 RPM depending on installation, without a single fixed maximum, so check the plate on the spindle you actually have before you start. The TTC-H40 drives its X and Y axes with trapezoidal lead screws on tube rails and rides the Z axis on linear rails, so treat it like a lead-screw router and let your cut settings, not the frame, carry the work. Depth per pass is still where the machine's build sets the limit: 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. Work up to deeper passes gradually rather than assuming the machine can take a full-diameter cut right away. 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. Two Trees states this spindle's range as 8,000 to 30,000 RPM depending on installation rather than one fixed maximum, so check the plate on yours; the example below keeps the generic 16,000 RPM chart value. 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.