Brand: SainSmart

Genmitsu 3040 Y-Axis Extension Kit for 3018 Series CNC Router

SKU: 101-63-YS3018 50 reviews Variants ID: 32781692076111

Super Size your CNC: This kit will extend your CNC’s Y-Axis to have 370mm of movement (14.6”), 320mm of travel, easily convert your 3018 to a 3040.

Compatibility: Perfectly compatible with Genmitsu 3018-PRO, 3018-MX3, 3018-PROVer, 3018-PROVer Mach3 CNC’s.

Built to suit your needs: It is designed to be a direct upgrade to the 3018 series CNC machines. The enlarged 3040 MDF Spoilboard and 3040 Aluminum Spoilboard are available now.

Simple Assembly: We will take you through the assembly process every step of the way.

Cost-Effective: Save money by putting your current CNC to better use. You don’t need to spend tons of money on a bigger one.

Note for Bakelite 3018-MX3 User: Please check the screw hole of the optical shaft part.
COUNTERBORE in the screw hole:   ▶ 3018-PROVer Series
SPOTFACE in the screw hole:  ▶ 3018-PRO
Ship to
Expand your machine's potential with an easy upgrade that will provide over double your previous work area.

Perfect for making signs or just accommodating larger stock material for multiple cuts.

How to assemble the Extension Kit

Step 1: Disassembly

  • Disconnect & Remove All Wires Connecting to the Base of Your CNC
  • Unscrew the Gantry Assembly from Either Side of the CNC's Base
  • Take Apart Your Frame

Step 2: CNC Base Assembly

  • Attach the Extended Side Extrusions & Linear Rails to the Back Panel
  • Install Extended Lead Screw into CNC Bed Through Spring & Copper Nut
  • Install the Bed with Threaded Lead Screw Into the Liner Rails Already Attached to Back Panel
  • Secure the Lead Screw to the Y-Axis Stepper Motor through the Coupler
  • Install the Front Panel & Square Frame

Step 3: Final Assembly

The process of mating the base frame with the gantry assembly mirrors the same process as when you assembled your CNC for the first time, the only major difference is that rather than having the gantry spaced 46.5mm from the rear of the frame, you are now going to want it to move more forward in order to take advantage of the expanded Y-Axis.

Rather than give you a specific number, it is strongly suggested that you move the gantry as far forward as your wiring will allow. This is usually around 60-80mm depending on whether you have limit switches.


Material: Aluminum
Package Weight: 1.77 KG (3.90LB)
Package Dimension: 51.5*21.5*7.5cm

Note for 3018-MX3 User: Since MX3 has been upgraded before, special attention should be taken when choosing this Extension Kit. If you find a COUNTERBORE in the screw hole of the optical shaft part, please choose the Extension Kit for 3018-PROVer/3018-PROVer Mach3.


For 3018-PROVer Series:
2 x Y-axis Aluminum Extrusions (2040*450mm)
1 x Y-axis Extended Lead Screw (T8 Pitch 2mm, Thread 4mm*450mm)
2 x Y-axis Extended Linear Rails (Hole 5mm, Depth 15mm*460mm)
1 x Replacement Zip-ties
1 x Assembly Instruction

For 3018-PRO& 3018-MX3 Series:
2 x Y-axis Aluminum Extrusions (2040*450mm)
1 x Y-axis Extended Lead Screw (T8 Pitch 2mm, Thread 4mm*454mm)
2 x Y-axis Extended Linear Rails (Hole 5mm, Depth 15mm*450mm)
1 x Replacement Zip-ties
1 x Assembly Instruction


1 x Y-axis Extension Kit + MDF Spoilboard


Assembly Guide

Customer Reviews
4.9 Based on 50 Reviews
Write a Review Ask a Question
  • Reviews
  • Questions

Thank you for submitting a review!

Your input is very much appreciated. Share it with your friends so they can enjoy it too!

Filter Reviews:
Shane P.
United States United States
Simple install, doubles capacity

In about an hour, this was installed and working (including a separate spindle upgrade). Very pleased with this kit.

Francois O.
Strong and quality build !

Strong build and excellent component. Great and fast service. You can trust SainSmart and Genmitsu !

United States
Outstanding product

Perfect fit, easy assemblu.

Alex g.
Canada Canada

These came quickly and were super simple to attach! Defiently recommend to anyone looking

Tim R. Rosencrans
United States

Good price quick setup. I Purchased the expansion with the base model so I had most everything set up before the extension arrived and just had to finish that up. Very sturdy.

Richard L.
United States United States
Great expansion

The extension installed with no trouble. All pieces fit well and the new expansion works well.

Greece Greece
Extension kit CNC 3018

Excellent quality, easy to install and quite useful for upgrade. I hope an even larger ugrade on both axis will emerge soon after!

United Kingdom
Super-sized 3018 pro

Made the mistake of ordering the wrong set so had to drill out the ends to accommodate the two guide rails. Works absolutely fine though but make sure you order the right one. Used a few times now so very happy with my super-sized 3018 pro.

Do not listen to these reviews.

People that don't know the difference between part numbers and what they have are putting bad reviews. This kit is for flush mount 3018Pro. The longer shafts are for the counter sunk 3018PROVer.

R. Torres
United States
The extension is GREAT! But what is better is the customer support?

The product is perfect, I would almost say if you are serious you need this.. They are cut exactly and a simple swap. What honestly was better was what defines a company, there was a problem. Sainsmart actually took care of the problem no questions asked. What is worse is it may have been my fault (embarrassingly understood later) and I think they knew it. Made a customer for life!! THANKS HONG!