Genmitsu Offline Control Module

What it handles, and nothing more:

• Manual jogging: X, Y and Z move from the buttons, so the starting corner of a job is set by eye.
• Spindle switching: on and off by hand, for a test spin or a clean stop.
• File running: G-code on the SD card is recognised and run directly.
• File loading: copy files with a card reader, or connect the module to a computer by micro USB and store them on the card.

The appeal is physical freedom. A 3018 is noisy and throws chips, and many owners would rather keep it in a garage or workshop than next to a laptop. With the module, the computer is used once, to make the file in the CAM program, and never has to share a bench with sawdust.

It also helps on long runs. A USB cable that drops out mid-job leaves a GRBL machine stranded halfway through a relief carve. Running from the card keeps the stream local to the machine, so a sleeping laptop or a tugged cable no longer ends the job.

A pine coaster set is a good first test: small, quick and forgiving of a slightly high zero.

1. With the machine off, plug the module's cable into the matching port on the 3018-PRO controller board.
2. Export the job from Easel, Carveco, Fusion 360 or another CAM program as G-code.
3. Copy the file to the SD card with a card reader, or connect the module to the computer by micro USB and save it straight to the card.
4. Power the machine, jog the bit to the job origin and lower Z until it just grips a sheet of paper.
5. Set that point as zero, start the spindle, choose the file and run it.

Keep file names short and plain. Small handheld screens show only a few characters, and a folder full of files named job-final-2 is hard to tell apart on a tiny display.

Walnut, acrylic and FR4 from the card

The module has no idea what material is on the bed; the feeds and depths are all in the file. That makes a tidy habit worthwhile:

• Put the material and bit in the file name: walnut-3175-flat, acrylic-single-flute.
• Keep one test square per material on the card for new bits.
• For FR4 circuit boards, keep the zero exact: isolation cuts are only a fraction of a millimetre deep.

Offline running pairs well with a Z-axis touch probe used from the computer beforehand, or with a careful paper-slip zero at the machine.

• GRBL settings: steps per millimetre, maximum spindle speed and laser mode are set from a sender on the computer.
• Probing routines: automatic tool setting belongs to the newer PROVer V2 controller and to computer senders.
• Toolpath preview: there is no visual preview on a small screen, so check the path in the CAM program before copying it.
• Mid-job edits: a file that needs a change goes back to the computer.

That split is fine for most hobby work. Make and check the file on the computer, then run it at the machine. For GRBL settings and senders, see 3018 CNC software.

Faults worth ruling out

• Blank screen: reseat the cable at both ends with the power off.
• File not listed: check that it was saved as G-code and sits where the module can read it.
• Machine moves the wrong way: the zero was set in the wrong corner; re-jog and re-zero before blaming the file.

None of these need a new part; they are the usual first-week slips with any handheld controller.

One more habit saves blanks: run each new file once in the air. Set zero a few centimetres above the stock, start the job and watch the spindle trace the outline. If the path wanders off the blank or dives too deep, the fault is in the file, and a pine offcut survives the lesson.

Choose the offline module if:

• The machine is a 3018-PRO, 3018 or 1810-PRO.
• Buttons and a card are all the remote control you need.
• You want the lowest-effort way to free the laptop.

Look further if:

• You own a PROVer V2: its own controller is the one that fits.
• You want to start and watch jobs from a phone.
• The board itself is failing; a replacement 3018-PRO controller board has the offline port.

A useful test before buying: count how often the laptop sits beside the machine only to press start. If that is most jobs, the module earns its bench space on the first weekend. If the computer is there anyway for probing and previews, a Wi-Fi link or a better sender may help more.

The 3018-PRO kit already includes an offline controller, so this module mostly serves as a spare, a replacement, or an add-on for older 3018 and 1810-PRO machines. The upgrade order shows where it ranks among other parts.