The CNC router from China commonly referred to as 3018 Pro CNC Router is fairly inexpensive and can be upgraded fairly easily. This Thing will help you install limit switches which help prevent damaging the machine by crashing it.

This thing is intended to be used with the Pro version which is made of both extruded aluminum and CNC routed plastic parts. The standard version is mostly made of extruded aluminum. While this might work with both, I do not have a standard version to test it with.

For the Z Axis upgrades see: https://www.thingiverse.com/thing:3663872

3D Printed Parts

Qty 2 - X-Axis Limit Switch Holder V2.STL
Qty 2 - Y-Axis Limit Switch Holder V2.STL
Qty 8 - T-Nut V2.SLDPRT

Limit Switches

Qty 4 - Limit Switch model: V-153-1C25
Micro Limit Switch Long Straight Hinge Lever Arm SPDT Snap Action

https://www.amazon.ca/gp/product/B07DGX5Q1Q/

https://www.digikey.ca/product-detail/en/omron-electronics-inc-emc-div/V-153-1C25/Z4613-ND/1829013

You can search AliExpress for "V-153-1C25" just make sure you get one with a long arm as specified by the model number. The long arm is is needed for the X Axis.

Note: the Y axis will work with a medium style arm, but the long one works fine.

Hardware

Qty 16 - M3 nut
Qty 4 - M3x12mm screw
Qty 8 - M3x16mm screw
Qty 4 - M3x20mm screw

Here is an example of a kit which includes the the hardware you will need. You could get much cheaper hardware if you take the time to look for it (and maybe wait for it to ship from China)

https://www.amazon.ca/gp/product/B06Y4N8XWG/

CNC Router

You can find this router all over the place, eBay, Amazon, AliExpress, Banggood, etc..

Search these sites for 3018 Pro CNC Router

Here are a couple example links.

https://www.amazon.ca/gp/product/B07GPTGN5J/

https://www.sainsmart.com/products/sainsmart-genmitsu-cnc-router-3018-pro-diy-kit

Note: the SainSmart site shows various models of 3018 router including the Pro and non-Pro version.

The main differences between the different 3018 Pro CNC Router versions you find online is the inclusion or exclusion of options (range: $100 to $300USD):

• Offline Controller (lets you use the machine without a laptop attached)
• Laser (lets you engrave/burn with a somewhat low powered 2W to 5W laser - as opposed to a high powered 50W+ CO2 cutting laser found on laser cutting machines)
• Collet chuck (sometimes called ER11, centres the milling tools more accurately)
• Cutting bits
• Mounting hardware (to hold down your raw stock)