Genmitsu Aluminum Z-Axis Assembly V2

What arrives in the box:

• An aluminium spindle carriage with linear bearings and limit switches already fitted.
• Two spindle mounts: 43 mm for the standard 775 motor and 52 mm for a 300–500W spindle.
• A rotary knob on top that raises and lowers Z manually, power off.
• Room for more: 65 mm and 69 mm mounts, sold separately, take a compact trim router.

The V2 changes one thing over the V1 that matters a lot: Genmitsu lowered the spindle mount on the carriage, which lifts effective Z travel from 40 mm to 56 mm. That extra 16 mm is room for a vise, a thicker blank or a longer bit.

Brass is the best test of the upgrade. On a nylon carriage, engraving brass often leaves a faint ripple along each stroke; with the carriage in aluminium and a sharp V-bit, the edges come out clean. Aluminium sheet follows once feeds and chip clearing are sorted.

For wood-first owners, the extra depth may matter more than the stiffness. Carving deep relief into a 50 mm walnut blank asks for more travel than the stock 3018-PRO's 45 mm can give.

Jobs that open up:

• Walnut and oak blanks thick enough for bowls, trays and deep relief.
• A small machine vise on the bed, holding aluminium parts.
• Longer end mills for deeper profile cuts in one setup.
• A trim router on the 65 or 69 mm mount for heavy wood work.

The costs to plan for:

• A 300–500W spindle brings its own supply and speed controller; it does not run from the stock 24V board.
• The 52 mm spindle needs a 52 mm dust shoe, since the 42 mm shoe no longer fits.
• The assembly puts 1.89 kg on the gantry, so keep rapid moves sensible.

Whether a given 300–500W kit takes speed commands from GRBL depends on its controller. Check before relying on S-words in the file, or plan to set speed by hand.

1. Power down and photograph the existing wiring on the Z axis.
2. Remove the spindle and the old Z carriage from the gantry.
3. Bolt the V2 assembly to the gantry, snug but not tight, and check it slides true.
4. Tighten the fasteners evenly, then fit the Z stepper and reconnect its cable.
5. Reconnect the pre-installed limit switches to the board's Z limit port.
6. Clamp the 775 in the 43 mm mount or the new spindle in the 52 mm mount.
7. Tram the spindle: sweep a bit across the bed and adjust until it is square in both directions.

After fitting, check the machine still knows how far Z moves:

• Command a 10 mm Z move and measure it with calipers.
• If it is off, correct the Z steps-per-mm value in GRBL, setting 102.
• Update the maximum Z travel, setting 132, if soft limits are on.

Run a short test in pine before metal: a square pocket shows at once whether the spindle is trammed and the carriage is tight. Then swap the dust shoe for a 52 mm model with the bigger spindle, and re-run a Z probe routine before the first cut. The 3018 software page explains GRBL settings in more depth.

Which mount to use:

• 43 mm: the stock 775 or the GS-775M, for a stiffer carriage without new electrics.
• 52 mm: a 300–500W spindle, for real aluminium work.
• 65 or 69 mm: a trim router, sold separately, for heavy wood removal.

Other routes to a stiffer Z exist. A generic 3018 Z sliding table offers a longer 90 mm stroke, and third-party 52 mm brackets fit some 3018-PRO frames. The Genmitsu assembly is the one designed around Genmitsu's own gantries, with switches already fitted.

The staged route works well. Fit the assembly with the 775 in the 43 mm mount first and learn how the stiffer carriage cuts brass and thin aluminium. Move to a 52 mm spindle only once the jobs call for it, since that step also brings a new supply, a new dust shoe and new feed rates to learn.

Settle three points up front: which machine and version, whether a new spindle and supply are part of the plan, and whether a 52 mm dust shoe will follow. The upgrade sits mid-way through 3018 upgrades in order of payoff, after probe, clamps and spoilboard.