A geared rotary attachment for Genmitsu's 3018-PROVer V2, 3020-PRO Ultra and 3020-PRO MAX V2 that turns the bed of a 3-axis router into a lathe-style holder for pens, handles and rings.
A 3-axis router sees the world as flat: X, Y and a depth. The Genmitsu rotary module adds a turning axis, clamping a round workpiece and rolling it under the spindle so a pattern can wrap all the way around. It is made for the 3018-PROVer V2 and for Genmitsu's 3020-PRO Ultra and 3020-PRO MAX V2.
The size limits frame every project: up to 40 mm in diameter and 184 mm in length. Within that envelope the maker names the natural jobs:
Engraving and 3D carving are both on the list. Engraving wraps a line or text around the surface at a fixed depth, while 3D carving shapes the surface itself, such as a spiral flute or a relief band. The second takes longer and asks more of the setup, because the tool is in the material for most of each rotation.
For most PROVer V2 owners, the rotary replaces a common workaround: engraving a flat patch on a round part and accepting the distortion at the edges. Now the text stays sharp all the way round. The Genmitsu 3018 line shows where the PROVer V2 sits among Genmitsu's 3018 machines.
| Spec | Value |
|---|---|
| Maker | Genmitsu |
| Model | 4AXIS-3018 |
| Compatible machines | 3018-PROVer V2, 3020-PRO Ultra, 3020-PRO MAX V2 |
| Maximum workpiece diameter | 40 mm (1.57 in) |
| Maximum workpiece length | 184 mm (7.24 in) |
| Stepper motor | 42HS48, high torque |
| Drive | 4:1 gear reduction |
| Maximum rotation speed | 200 rpm |
| Uses | 360° engraving and 3D carving |
| Software | Autodesk Fusion 360 rotary toolpaths |
| Installation | Plug-and-play, no hardware changes |
| Weight | 4.4 lb |
| Package size | 14.96 × 5.12 × 3.94 in |
| In the box | 4-axis rotary module kit |
Inside, a 42HS48 stepper drives the clamp through a 4:1 gear reduction. The gearing multiplies holding torque by roughly four and divides each motor step into a finer slice of rotation. Genmitsu contrasts it with belt-driven rotaries, which can slip or vibrate under load.
What the numbers mean in practice:
Holding torque matters most when the spindle bites on one side of the blank. A weak rotary lets the part creep backward a fraction, and the pattern misaligns when the path comes round again. Gearing and a longer motor are the defence against that creep.
| Workpiece | Job | Bit |
|---|---|---|
| Walnut pen blank | Wrapped name | V-bit |
| Maple handle | Grip texture | Small ball-nose |
| Acrylic rod | Spiral line | Single-flute |
| Brass ring blank | Surface engraving | Fine V-bit, light depth |
At 200 rpm, the rotary is also quick between cuts. Positioning moves that swing the blank half a turn finish in a fraction of a second, which keeps batch jobs short.
Diameter changes surface speed. A 40 mm blank moves its surface much faster per degree than a 10 mm ring, so feeds that suit one will be wrong for the other. Start slow on each new diameter and adjust from the first test.
Genmitsu describes the module as plug-and-play: no complex wiring and no hardware changes on the supported machines. On the software side, it is built to work with rotary toolpaths generated in Autodesk Fusion 360.
On a 3-axis GRBL controller, a rotary usually runs from one of the existing axis drivers, taking the place of the bed's motor while it is fitted. The steps-per-millimetre value for that axis then changes to suit the rotary's gearing. Follow Genmitsu's own setup notes for the exact port and value on the PROVer V2 and 3020 machines.
Centring is the step that decides quality. If the blank's axis sits off the rotary's axis, the surface rises and falls as it turns, and depth varies around the circumference. Check with a dial indicator or by touching off on the top at several angles.
Software and settings are covered on 3018 CNC software.
Genmitsu names three machines for the rotary: the 3018-PROVer V2, 3020-PRO Ultra and 3020-PRO MAX V2. The plain 3018-PRO kit is not on the list, and other 3018 frames are not named either. That fit list is the first thing to check.
| Setup | Round work | Best for |
|---|---|---|
| Rotary on a 3018-PROVer V2 | Full wrap, engraving and 3D carving | Pens, handles, rings |
| 5W laser on a flat bed | Flat patch only | Flat signs, coasters, leather |
| PROVer V2 Y extension | None | Longer flat work, to 420 mm of Y |
The rotary earns its place when:
Look elsewhere when:
Batch work is where the rotary pays back fastest. Once one pen blank is centred and zeroed, the next blank of the same diameter drops into the same clamp and runs the same file with only a name changed. A set of ten engraved pens is an afternoon, not a weekend.
Z clearance deserves a final check. The rotary lifts the blank off the bed, and the spindle needs room above a 40 mm workpiece plus the bit. Measure the gap between the collet and the clamp's centre line before a first large blank. The upgrade order treats the rotary as a late add-on, after probes, clamps and switches.
Genmitsu lists the 3018-PROVer V2, 3020-PRO Ultra and 3020-PRO MAX V2. The 3018-PRO is missing from it.
Up to 40 mm (1.57 in) in diameter and 184 mm (7.24 in) long.
Genmitsu names Autodesk Fusion 360 for rotary toolpaths.
A 42HS48 stepper through a 4:1 gear reduction, with a maximum rotation speed of 200 rpm.