Doesbot 3018 MDF Spoilboard

It is sized to the machine rather than cut from a sheet:

• 300 × 180 mm, the length and width of a standard 3018 bed.
• 12 mm thick, enough to resurface many times.
• 24 holes, M6 × 1, spread across the board for clamps and hold-downs.
• Made for 15180 profile tables 300 mm long, the aluminium bed most 3018 frames carry.
• Screws included for fixing it down.

MDF suits the job for plain reasons. It is uniform all the way through, with no grain to tear or knots to deflect a bit. It machines flat with a wide cutter. And it is cheap enough to replace when it is finally too scarred or thin.

Plywood and hardboard are sometimes used instead. Plywood voids and glue lines make surfacing uneven, and hardboard is thin, so a purpose-cut MDF board with its holes already placed saves both the sawing and the drilling.

A spoilboard is among the first three parts most 3018 owners add, alongside a probe and better clamps, as set out in 3018 upgrades.

Three ways to hold stock on the board:

• Clamps in the M6 holes. The 24 holes put an anchor within reach of most blanks, so small parts can sit anywhere, not only at the T-slots.
• Double-sided tape. Good for thin acrylic and PCB, which bow under edge clamps. It only grips well on a clean, flat, freshly surfaced board.
• Screws through waste areas. Short wood screws into the MDF hold a plywood blank where clamps would get in the bit's way.

Tabs matter as much as depth. Leave three or four small bridges on each part so it cannot spin free and meet the bit on the last pass. Cut the final pass at the same feed as the rest; slowing down in the spoilboard only burns the MDF and dulls the bit. Material starting points for these cuts are in what a 3018 cuts.

1. Screw the board to the aluminium table with the supplied screws, tight but not crushing the MDF.
2. Fit the widest flat end mill or surfacing bit the collet takes.
3. Set Z zero on the highest point of the board.
4. Run a pocket over the whole board, 0.2–0.5 mm deep, with 40–50% stepover.
5. Vacuum the dust, then check flatness with a straightedge.
6. Seal lightly with a dry finish if desired, never oil.

Points to watch:

• Z budget. The board raises the work surface by 12 mm. On a 3018 with 45 mm of Z, that leaves less clearance for thick stock and long bits. Check the lowest Z position still reaches below the board's top.
• Hole alignment. On frames other than a 300 mm 15180 table, the fixing points may not line up. Check before drilling new holes.
• Resurface sparingly. Each pass removes MDF. Skim only as deep as the scars go.
• Dust. MDF dust is fine and gets everywhere; a dust shoe and vacuum help.

Surfacing toolpaths are easy to make in Easel or Carveco, covered in 3018 CNC software.

Pick the Doesbot board if:

• The machine has a standard 300 mm 15180 aluminium table.
• Clamping flexibility matters: 24 holes spread across the board.
• The work is wood, plastics and PCB, cut dry.

Pick the LUNYEE board for a LUNYEE frame, where its hole spacing is designed to match, or when a printed grid would help place blanks. Pick an aluminium T-slot bed when the plan includes a bed extension and heavier workholding.

Whichever board goes on, treat it as a consumable. After many resurfacings, when the holes run shallow or the board goes thin, replacing it costs less than one ruined blank.

A spare board on the shelf also opens a useful trick: keep one surfaced board for tape-held acrylic and PCB work, where flatness is everything, and a second for screwed-down plywood jobs, where holes and scars do not matter. Swapping them takes the few minutes needed to undo the fixing screws.

The first surfacing pass on any new board is also the best time to check tram and gantry square, before a real project depends on them.