Genmitsu 3018 MDF Spoilboard

What a spoilboard does for a 3018:

• Protects the bed and the bit. A cutter that grazes aluminium dulls at once; one that grazes MDF does not notice.
• Gives a flat reference. Once surfaced, the board sits exactly square to the spindle, which matters for engraving and PCB work.
• Holds clamps. Sixteen M6 holes take hold-downs and side clamps anywhere across the bed.
• Takes screws and tape. Stock can be screwed into the waste or taped down, which aluminium profile does not allow.

MDF is the classic material for the job. It is dense, uniform and has no grain, so it cuts the same in every direction and surfaces flat. At 300 × 180 mm it matches the 3018 working area, and at 1.1 lb it barely changes the load on the Y axis.

Plywood is the material that makes the case. Cutting a sign out of 6 mm birch means cutting a hair deeper than 6 mm, and that last fraction has to go somewhere. With a spoilboard, it goes into something designed to be cut.

1. Fit the board to the bed and check every T-nut is gripping.
2. Fit the broadest flat cutter that suits the collet; a surfacing bit on a 1/4 in shank needs a matching ER11 insert.
3. Touch off Z where the board sits highest.
4. Run a pocketing toolpath over the whole surface, about 0.2–0.3 mm deep, with generous stepover overlap.
5. Vacuum the dust and check with a straightedge; repeat only if low spots remain.

Take off only what flattening needs. Every millimetre removed shortens the board's life. Mark the date and depth of each surfacing pass on the board's edge in pencil, and it is easy to see how much is left.

Limits to keep in mind:

• The board raises the stock by 12 mm, so tall blanks sit closer to the gantry; check clearance under the spindle on a machine with 45 mm of Z.
• The M6 holes are fixed; a clamp can only sit where a hole is.
• Heavy screw use near the edges wears the MDF around the holes over time.

1. Check the underside against the installation drawing, then loosen all six T-nuts a few turns so they can move.
2. Turn the board so each T-nut lines up with a slot in the bed.
3. Lower the board so the T-nuts drop into the slots.
4. Tighten each hex screw as far as it goes without forcing it; the T-nut turns and locks in the slot.
5. Lift each corner of the board to confirm every T-nut has caught.

A T-nut that has not rotated into its locking position will let one corner lift under cutting load. The corner test in the last step is the quick way to catch it.

Once fitted, surface the board before the first precision job. MDF from the factory is flat, but the bed under it has its own small errors, and surfacing makes the top face square to this spindle on this machine.

Workholding options after fitting:

• Side clamps, such as the Fuzqq four-pack, in the M6 holes.
• Genmitsu's T-track mini hold-downs, in the same holes.
• Screws or brad nails into the waste of plywood stock.
• Painter's tape and CA glue for thin acrylic and PCB blanks.

The grid is worth it for anyone placing stock by eye: blanks line up with the printed scale and the denser holes suit small clamps. The plain board is fine for surfacing-heavy use, where the grid would soon be machined away.

Many owners keep a second plain board on the shelf. Swapping a worn board for a fresh one takes minutes with the T-nuts, and the old one can be surfaced at leisure or kept as a dedicated board for through-cuts while the new one stays clean for engraving.

The bundles add one useful extra:

• Clamps, for holding stock from the first job.
• ER11 collets, for bits with shanks other than 1/8 in.
• A 24V 20,000 rpm 775 spindle, for faster cutting in wood.
• End mill sets, for owners still breaking bits while learning feeds.

PROVer V2 owners should check before ordering. That machine has a one-piece aluminium spoilboard, and Genmitsu's own notes disagree on whether the grid board fits it. The wider upgrade sequence is on 3018 upgrades, and the 3018-PRO kit can be bundled with this board.