Some 3018 CNCs already have a 12 V pin on the main board that can be used to power a small 12V pump. However, you may already have an external mains-powered air pump or a compressor (e.g. if you have an aquarium) that you can use as a laser air assist. While you could operate it manually, it would be more convenient to have it turn on and off automatically with the laser, just like the original one.
This project aims to create an automatic air assist with an external air pump.
1×
ACO Air Pump
These cheap air pumps are found on AliExpress, usually having ACO in their name. They differ in sizes and air flow, choose one for your needs.
3×
KF301-5.0-2P Terminal Block Connector
2 or 3 of these are required depending on whether you want manual bypass switch or not
1×
SRD-12VDC-SL-C
This relay does all the magic
1×
JST B2B-XH-A
2-pin JST XH wire to board connector is used to connect the 3018
2×
JST XHP-2
2 male JST XH connectors are required to make a control cable
There are numerous ways to assemble this project, and the required components vary depending on your approach. For example, you can directly connect the pump to the controller using a pair of crimped wires, or you might opt to link the controller with a socket, allowing the pump to be connected without rewiring by utilizing its plug. To construct this control box, you may need to acquire additional parts, such as a socket and a 3D-printed housing. Alternatively, you could house the controller in a flush-mounted box or use both a box and a 3D-printed housing. It's also feasible to incorporate a manual bypass (i.e., the capability to operate the pump using a conventional switch). For this, an extra piece of wire and a switch will be necessary. Consult the list of components provided here as a starting point.
For the tools, you'll need:
A soldering iron, solder, flux, etc.
A screwdriver
A wire-cutting multi-tool or a knife
A JST crimper tool is highly recommended to have
2
Making a PCB
This is the V1 of the controller, having two outputs. Later I decided to leave only one.
While you could opt for point-to-point connections, utilizing a Printed Circuit Board (PCB) offers a more reliable method for assembling the electronics.
For those without any prior experience, the simplest way to obtain a PCB is to employ a service such as JLCPCB or PCBWays. I personally have experience with the latter. Simply upload the controller.zip with the Gerbers and you should receive your PCB shortly.
Alternatively, if you're up for the challenge, you can manufacture the PCB yourself, even with your 3018 CNC machine! Use the provided Gerber files and the schematic for your guidance.
3
Soldering the PCB
If you opted not to use a service for PCB assembly, the responsibility falls on you. Simply go ahead and solder it yourself.