A set of four metal linear slide units, a T8 nut seat and a copper nut, with the screws and slot nuts to fit them, for 3018 Pro and 3018 Plus machines on 10 mm or 12 mm rods.
Every 3018 moves on round guide rods, with linear bearings riding along them and a T8 lead screw pushing the load. On many budget frames the bearing housings and nut holders are moulded parts. This kit swaps them for metal: four linear slide units, a T8 nut seat and a copper lead nut, with the screws and slot nuts to bolt it all together.
The kit comes in two block sizes, and the letters on each block say which:
What changes after fitting is how the carriage sits on its rods. Metal housings hold each bearing square and do not creep or crack under clamping load, which moulded parts can do after months of vibration. The result is a carriage that stays aligned, and fewer mystery steps in a pocket floor.
The kit keeps travel the same. It is a repair and stiffening part, not an extension, so a 300 × 180 mm machine stays 300 × 180 mm after fitting.
| Spec | Value |
|---|---|
| Slide units, 10 mm version | 4 × SCV10VUU for 10 mm rods |
| Slide units, 12 mm version | 4 × SCS12VUU for 12 mm rods |
| Lead screw | T8, 4 mm lead (4 mm per turn) |
| Nut seat | 1 × T8 nut seat |
| Lead nut | 1 × T8 copper nut kit |
| Slot nuts | 10 sliding nuts |
| Cap screws | Hex socket: 8 × 30, 8 × 25, 2 × 12, plus 2 × M3 × 10 |
| Material | Metal |
| Compatible machines | 3018, 3018 Pro, 3018 Plus |
| Model options named | 3018 Plus: SCS12VUU; 3018 Pro: SCV10VUU |
| Size (packed parts) | 3.15 × 1.97 × 0.79 in, 10 mm kit |
| Weight | 11.2–13 oz, by version |
| In the box | 1 X-axis upgrade kit |
Ordering the wrong block size is the one way to waste this kit. The two versions look alike in photos, and the difference is only 2 mm of bore. Five minutes with calipers settles it.
The model names help as a first guess. Kits name the 3018 Pro with SCV10VUU blocks and the 3018 Plus with SCS12VUU. Other upgrade makers state a 10 mm guide rail for the 3018 Pro series, while LUNYEE's 3018 Pro Max runs 12 mm rods.
The screw lead matters too. The nut seat and copper nut are made for a T8 screw moving 4 mm per turn. A screw with a different lead needs a matching nut, and the GRBL steps-per-millimetre setting must match the screw on the machine, whatever nut is fitted.
Installation is a bench job of an hour or two. The goal is simple: rods parallel, bearings free, nut centred on the screw. Most of the benefit comes from alignment done patiently, not from the metal alone.
If the carriage binds at one end, the rods are not parallel or a block is twisted. Loosen, push the carriage to the tight spot and snug the screws there. The copper nut should turn smoothly along the full screw; any tight patch means the nut seat is pulling the screw sideways.
A good test after fitting is a pocket in MDF. Cut a 40 mm square pocket 1 mm deep with a 1/8 in flat end mill and run a fingertip across the floor. Ridges that repeat along one axis point back at that axis's alignment.
GRBL settings and senders are covered on 3018 CNC software.
Metal slide units cure a specific problem: loose or worn bearing housings. Other upgrades target other weak points, and on most 3018s the Z carriage flexes before the moving axis does. The right order depends on what the machine is doing wrong.
| Upgrade | Fixes | Changes travel? |
|---|---|---|
| This slide-unit kit | Worn or cracked bearing housings | No |
| Daedalus X/Y kit | Short Y travel, plus an aluminium X knob | Y from 290 to 450 mm |
| Genmitsu Y extension | Short Y travel on a 3018-PRO | Yes, to 3040 size |
| Aluminium Z Assembly V2 | Z flex, spindle options | Z range 40 to 56 mm |
Choose the slide-unit kit when:
Start elsewhere when:
Several makers sell the same kit under different names, with near-identical parts lists and weights between 11.2 and 13 oz. The name matters less than the block size: pick the version whose blocks match your rods, and check that the parts list includes the nut seat and copper nut rather than slide units alone.
The upgrade order puts a probe and clamps ahead of any motion part. For the 3018 Pro frames that take this kit, see 3018 Pro machines.
Kits name the SCV10VUU blocks, for 10 mm rods, for the 3018 Pro. Measure your rods with calipers before ordering.
The rod size: SCV10VUU slide units run on 10 mm rods, SCS12VUU on 12 mm rods.
No. It replaces bearing housings and the nut seat; travel stays the same.
A T8 screw with a 4 mm lead, meaning 4 mm of travel per turn.
