Meissa CNC Meissa 3 XL

About the Machine

The Meissa 3 XL is the Meissa 3 fitted with the 'Rallonge XL' Y-axis extension, sold in Meissa CNC's BDM3 pack. It shares the Meissa 3's design: a 3D-printed frame, NEMA17 stepper motors, and belt drive on all axes. It takes a compact router that you supply (not included), held in the Meissa 3's 65mm or 70mm tool holder. It keeps the Meissa 3's X and Z travel (a 20.5 x 14 x 2.5 in / 520 x 355 x 64 mm envelope) with a longer Y from the XL extension; Meissa does not publish the exact extended Y dimension. It runs GRBL on an Arduino Uno over USB, so it works with Easel as well as Meissa's PilotCNC sender, UGS, and Candle. This is a light-duty hobby machine, so favor shallow passes.

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 Meissa 3 XL is the belt-driven Meissa 3 on a 3D-printed frame with NEMA17 stepper motors, fitted with the Rallonge XL Y-axis extension. It is a light-duty hobby machine, so keep passes shallow. As a general rule, a truly rigid, powerful machine 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 frame that will not flex, and enough mass to soak up vibration; a belt-driven printed-frame machine like this is not that, so favor 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. Meissa CNC does not state a spindle RPM for this configuration, so check the plate on your own tool and use its actual top speed in place of 16,000 if it is 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.