Top 3018s
Genmitsu 3040 T-Slot Aluminum Spoilboard
ASP3040P · aluminium T-slot bed · 3018-PRO

Genmitsu 3040 T-Slot Aluminum Spoilboard

The metal half of Genmitsu's 3040 upgrade: an aluminium T-slot profile that joins the 3018-PRO's own bed plate, so the longer Y axis from the extension kit has a flat, clampable table to run over.

  • ModelASP3040P
  • MaterialAluminium, smooth finish
  • ClampingT-slots on both sides
  • Works withGenmitsu 3040 Y-axis extension kit
  • Fits3018-PRO
  • Does not fit3018-PROVer V2
Suits
  • You are extending a 3018-PRO to 3040 with Genmitsu's Y-axis kit
  • You want a metal bed for T-track clamps and jigs instead of bare MDF
  • You cut long parts such as signs, rulers and guitar-pedal panels
Skip if
  • A 3018-PROVer V2: it has its own 3040 aluminium spoilboard
  • A stock 3018 with no Y-axis extension fitted
  • Frames whose bed profile differs from the 3018-PRO's
Get it here

Turning the 3018-PRO bed into a 3040 aluminium table

A 3018-PRO leaves the factory with a 300 × 180 mm aluminium bed made from extruded profile. Genmitsu's 3040 Y-axis extension kit lengthens the rails, screw and frame so the table can travel further, and this T-slot aluminium top supplies the extra bed surface that the longer axis needs.

The idea is simple. The original bed profile stays on the machine, the new profile from this kit joins it, and together they form a table long enough for a 3040-class working area. Genmitsu calls the result a 3040 aluminium spoilboard, meaning a metal table on which a sacrificial MDF board or a jig sits.

  • Model: ASP3040P, sold for the Genmitsu 3018-PRO.
  • Material: aluminium with a smooth machined top.
  • Slots: T-slots run along both sides for clamps and fixtures.
  • Size: Genmitsu gives about 360 mm (14.17 in) across and about 9 mm (0.35 in) of height.

This part does nothing by itself. Without the Y-axis extension kit, the frame and lead screw stay 3018 length, and a longer bed would simply overhang.

Order as a pair. The spoilboard and the Genmitsu 3018 Y-axis extension kit are two halves of one upgrade. Genmitsu also sells them together in a single box.

What changes on the bench is the length of stock the machine can reach. On a 300 × 180 mm bed, 180 mm caps how tall a sign or panel can be; the 3040 conversion lets longer boards, name plates and panels go under the bit without flipping or tiling the job. The upgrade order entry places this conversion after the probe, clamps and spindle work that pay off sooner.

Measurements

The spec log

SpecValue
ModelASP3040P
MakerGenmitsu
Part typeT-slot aluminium table top, spoilboard extension kit
MaterialAluminium
SurfaceSmooth finish for mounting spoilboards or jigs
Clamping slotsT-slots on both sides
Width14.17 in (about 360 mm)
Height0.35 in (about 9 mm)
How it installsJoins the original 3018 aluminium bed profile
Result3018 aluminium bed extended to 3040 size
Required with itGenmitsu 3040 Y-axis extension kit
FitsGenmitsu 3018-PRO
Not compatible3018-PROVer V2
ClampsWorks with most bench clamping systems (T-nuts, T-track hold-downs)
Top surface useBase for an MDF spoilboard or specialty jigs

Clamping long walnut sign blanks in the T-slots

A metal bed with slots changes how stock stays put. Instead of screwing through the workpiece or relying on double-sided tape, T-nuts slide into the slots and hold-down clamps bolt to them anywhere along the table.

That flexibility is the main everyday gain. On a long sign blank the clamps can sit at the ends, out of the toolpath, and move along the slot for the next job without drilling a single new hole.

  • T-track hold-downs: the Genmitsu and LUNYEE mini clamps are sized for 3018 slots and take stock up to about 45 mm thick.
  • Low-profile side clamps: tiger-claw clamps grip from the edge and leave the whole top face open for engraving and flattening.
  • Jigs: a plate with dowel pins or a fence bolts down through the slots and returns to the same spot each time.
  • Spoilboard on top: an MDF sheet screwed to the aluminium protects it from the bit and gets resurfaced when it wears.

For walnut, oak and other hardwood signs, clamp near the cut rather than only at the ends. A long board that is held only at its tips will chatter in the middle, and the finish shows it.

JobHold-down on the 3040 bed
Long hardwood signSide clamps along both edges, spaced every 100–150 mm
Thin acrylic sheetMDF spoilboard plus blue tape and CA glue
6061 aluminium plateMetal clamps bolted into the slots, light passes
Repeat partsA bolted jig with a corner stop

Keep the bit away from the aluminium itself. A through-cut in plywood needs an MDF layer under the stock, or the end mill finishes its pass in the table.

In the lineup

Where it lands among 3018 gear

3018 CNC machine models by type, September 2026. Highlighted: Genmitsu 3040 T-Slot Aluminum Spoilboard.

3018-PRO only: why the PROVer V2 needs a different bed

Genmitsu is clear that this table top is not for the 3018-PROVer V2. The PROVer V2 uses a one-piece aluminium spoilboard and its own Y-axis extension, so it has a matching 3040 aluminium plate of its own design.

The difference comes from the bed construction. The 3018-PRO bed is built from aluminium profile that can be extended with another length of profile, which is what this kit supplies. The PROVer V2 bed is a single machined plate, so a joining profile has nothing to join.

  1. 3018-PRO: this ASP3040P table plus the 3018 Y-axis extension kit.
  2. 3018-MX3: Genmitsu names the MX3 for the Y-axis kit; confirm the bed profile matches before ordering the aluminium top.
  3. 3018-PROVer V2: the PROVer V2 Y-axis extension kit with its own 3040 aluminium spoilboard, which Genmitsu rates for a 300 × 400 mm working area.
  4. Other brands: CNCTOPBAOS, RATTMMOTOR and VEVOR frames use their own profiles and screw lengths, so a Genmitsu bed piece is a gamble.

Installation follows the extension kit's steps. The longer Y rails and lead screw go in first, then the bed profiles are joined and squared to the gantry before anything is tightened fully.

Square before you cut. After joining the profiles, run a pen or V-bit along X at both ends of the bed. Any height difference shows up as a deeper line at one end.

Once the bed is square and flat, a 3040-size MDF sheet goes on top and gets surfaced with a flat end mill. Genmitsu's 3040 MDF spoilboard is cut to the same format, with threaded holes already in place.

  • Limit switches: move the Y switch to the new end of travel.
  • GRBL: raise setting 131, the Y maximum travel, to match the new length.
Swap-ins

Three other ways to go

Aluminium T-slot or 3040 MDF on top of the extension

An extended 3018-PRO needs some kind of bed across the longer axis. The two routes are this aluminium T-slot top, usually with a thin MDF sheet on it, or an MDF-only 3040 spoilboard fixed straight to the frame.

Aluminium costs more and weighs more, and it pays back in stiffness and clamping. MDF is cheap, easy to resurface and forgiving when a bit goes too deep, but it swells with moisture and threads wear out after many clamp changes.

PointASP3040P aluminium T-slot3040 MDF spoilboard
ClampingT-nuts anywhere along the slotsFixed threaded holes
StiffnessMetal profile, stays flatCan sag or swell over time
Bit strikesDamage the tableHarmless, surface again
Best underHardwood, aluminium, jigsPlywood through-cuts, PCB

Many owners end up with both: aluminium as the base, a sheet of MDF screwed on top as the sacrificial layer. That combination suits a 3018 that cuts a mix of wood, plastic and soft metal.

  • Before ordering: confirm the machine is a 3018-PRO and that the Y-axis extension kit is fitted or on its way.
  • Clamps: check that existing hold-downs use M6 T-nuts, the size most 3018 slots take.
  • Stock length: make sure the jobs in mind need more than 180 mm of Y, or the upgrade will sit unused.
  • Bench space: the extended frame needs room for the table to travel its full length, front and back, without hitting a wall or a monitor.

For owners still weighing a bigger frame, the price entry sets the cost of a 3040 conversion against a machine built at that size from the start.

Bench notes

Setup questions

Does this spoilboard work without the Y-axis extension kit?

No. It joins the original bed to make a 3040-length table, and only the extension kit lengthens the Y rails and screw to use it.

Will it fit a 3018-PROVer V2?

No. Genmitsu rules out the PROVer V2, which has its own 3040 aluminium spoilboard and extension kit.

What clamps fit the T-slots?

Clamps that use T-nuts, such as T-track mini hold-downs and low-profile side clamps with M6 hardware, are the usual choice on 3018 beds.

Should MDF go on top of the aluminium?

For through-cuts, yes. A thin MDF sheet protects the aluminium from the bit and can be surfaced flat when it wears.