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
Qty 4 - Limit Switch model: V-153-1C25
Micro Limit Switch Long Straight Hinge Lever Arm SPDT Snap Action
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.
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)
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.
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)
Y-Axis_Limit_Switch_Holder_V2.STL is the only part that prefers 60% infill since it sticks out a bit, this avoids flexing if you bump into it accidentally. You could print everything else at 20%, but it does not really matter.
Assemble the T-nuts by pressing in an M3 nut into the plastic part. Depending on your printer & settings, you might need to sand/file the part for it to slide smoothly in the aluminum extrusion channels.
Install the Right limit switch on X-Axis_Limit_Switch_Holder_V2.STL as shown above.
Bottom view of the Right side limit switch assembly. The M3 nuts should press in with your finger, however if it is too tight, you may need to press them in with a pair of pliers.
With the T-nuts installed in the aluminium extrusion, alight the M3x12 screws (showing the Right X-Limit switch)
Adjust the location of the limit switch until it switch trips before the X carriage hits the side wall, or some other component. Tighten the two T-nut screws firmly and test again.
It is important that there is a gap between the switch arm and the stepping motor otherwise there might be inconsistent results as the switch sometimes catches on the motor vs the plastic mount. You may need to carefully bend the arm a little.
Build and install the Left X-Limit switch the same way but flip the switch over this time.
Assemble, install and adjust the Front Y-axis limit switch in a similar way to the X axis. It will touch against the end of the table to detect the limit.
Wire the X and Y axis limit switches in parallel as shown.
Install the serial driver
Unzip the download from the previous step and run:
Upgrade Firmware Version 1.1f
These are the settings that are supposed to be used to upgrade the firmware.
note: if you have the offline controller it must be disconnected for this to work.
Note: the COM port depends on which COM port the board shows up on your computer.
Launch the GRBL Control Software
Run this control software
.\Software\Grblcontrol (Candle_1.1.7 )\Grblcontrol (Candler).exe
Note: the offline controller must be disconnected for this to work.
You can now connect using "Grblcontrol (Candle)" using the previous COM port and Baud 115200
Enable hard limits switches to CNC
Issue this command:
$21=1 turns on hard limits (which disables the machine if any of the limit switches are tripped.