CNC 3018 PRO: Build, Control and Program It

The machine has not been used for a long time.

The CNC 3018 PRO is a small desktop CNC router. This guide follows the whole path: unpack the parts, build the machine, wire it, control it from a Raspberry Pi and prepare a job in Fusion 360. It was used to cut wood and thin aluminium.

The parts

The kit comes in bags and boxes. This is the overview of the parts, and how they fit the machine:

The parts one by one

Build the machine

The steps below follow the photos of the build.

Step 1: the frame

Build the frame from the black profiles and fit the linear bearing holders on the rods of the Y axis.

Step 2: the lead screw and the table carriers

Fit the lead screw with its stepper motor and the nut in its holder, then the carriers for the table.

Step 2D: the table

Fit the aluminium T-slot table on the carriers.

Step 3: the side plates

Put the T-nuts in the bakelite plate and fix the plates to the frame as the uprights of the machine.

Step 5: the gantry with the Z axis

Fit the X-axis rods and lead screw with their motor, and the Z-axis carrier.

Step 6: the spindle motor

Put the spindle motor in the clamp of the Z axis.

Wiring the controller

The controller sits in its transparent case on the side of the machine. Its connectors are marked X-MOTOR, Y-MOTOR and Z-MOTOR, and there is a red power connector.

Plug in the motor cables, one to each axis, and route them along the frame.

Tidy the wires

Bundle the loose cables with the cable ties, so they cannot catch in the moving parts.

Control it from a Raspberry Pi

Instead of a laptop by the machine, a Raspberry Pi 3 B runs CNCjs, a web interface for CNC controllers that run Grbl, Marlin, Smoothieware or TinyG. You open it in a browser on any computer in the house.

Prepare the SD card

The screenshots show Raspberry Pi Imager 1.6.2:

1. Choose Raspberry Pi OS Lite (32-bit), the version without a desktop, released on 7 May 2021 at the time.
2. Choose the SD card as the storage.
3. Open the advanced options, set the host name to cncserver, enable SSH with a password for the pi user, and set your WiFi and the time zone.
4. Write the card.

Connect over SSH

Put the card in the Raspberry Pi and start it. After a minute you can log in from your computer:

ssh pi@cncserver.local

The first time, SSH asks you to trust the host. Type yes and then the password that you set.

Start CNCjs automatically

Install CNCjs as described in its own documentation. The service file below starts it at boot, and it expects the program at /usr/bin/cncjs. Save it as /etc/systemd/system/cncjs.service:

[Unit]
Description=A web-based interface for CNC milling controller running Grbl, Marlin, Smoothieware, or TinyG
Wants=network.target
Documentation=https://github.com/cncjs/cncjs

[Service]
Type=simple
User=pi
Group=pi
WorkingDirectory=/home/pi
Nice=5
ExecStart=/usr/bin/cncjs
# Use SIGINT to stop
KillSignal=SIGINT
# Auto restart on crash
Restart=on-failure
# Tag things in the log
SyslogIdentifier=cncjs

[Install]
WantedBy=multi-user.target

Then enable it and start it:

sudo systemctl enable cncjs
sudo systemctl start cncjs

A camera on the machine

A second service streams the Raspberry Pi camera with mjpg-streamer, so you can watch the job. It expects the program at /usr/local/bin/mjpg_streamer and uses the Raspberry Pi camera input:

[Unit]
Description=mjpg-streamer
Wants=network.target
Documentation=https://github.com/jacksonliam/mjpg-streamer

[Service]
Type=simple
User=pi
Group=pi
WorkingDirectory=/home/pi
Nice=5
ExecStart=/usr/local/bin/mjpg_streamer -i "input_raspicam.so"
# Use SIGINT to stop
KillSignal=SIGINT
# Auto restart on crash
Restart=on-failure
# Tag things in the log
SyslogIdentifier=mjpg_streamer

[Install]
WantedBy=multi-user.target

Both files are also in the gists of the author.

From model to G-code in Fusion 360

The repository has an example part, a round flange with holes, as a Fusion 360 file, Example.f3d. This is the path from the model to the G-code file, with the free personal version of Fusion 360.

1. Open the model

Choose File, Open and select Example.f3d. Then switch the workspace from Design to Manufacture, which shows the Milling tab.

2. Create a setup

A setup describes the material and where the zero point of the machine is. Choose the orientation with “Select Z axis/plane and X axis”, and put the origin on the stock. In the example the stock is a box with an offset of 5 mm on the sides and 5 mm on top, which gives a block of 100 by 100 by 17 mm.

3. Make the bit

Open the tool library and add a flat end mill. The bit in the example has these values:

4. Pocket the flange

A 3D pocket removes the material around the part. The machining boundary is set to the silhouette of the model, and the coolant is disabled, since the machine has none. The speeds are low, for a small machine:

5. Cut out the outline with tabs

A 2D contour follows the outline of the part. Tabs keep the part attached to the stock until the end, so it cannot move while it is cut loose, and the contour goes down in steps:

6. Post the G-code

Choose Grbl as the post processor, since the controller runs Grbl, the unit millimeters and a program number. Fusion writes an .nc file.

The comment in the file says that, in the personal use version, rapid moves are reduced to the feedrate of cutting, which can make a job take longer.

Choosing a bit

The shape of the bit decides what the cut looks like. These are the bits that are shown in the repository, each with a cut in wood.

Flat end mill and straight flute

A flat end mill cuts a pocket with a flat bottom. A straight flute bit has flutes that run straight along the bit. The slots in the photo have a clean, flat bottom.

Ball nose

A ball nose bit has a round tip. It leaves smooth curves, which suits shapes that are not flat.

Up cut and down cut

The spiral of the flutes decides where the chips go: a down cut bit forces the chips down, and an up cut bit forces them up. A down cut gives a cleaner top edge, and an up cut clears the chips out of the slot. The wood sample shows both.

V-groove and engraving

A V-groove bit has a pointed tip. It cuts letters and fine lines, and the width of the line depends on how deep the tip goes.

Surfacing

A surfacing bit is wide and flat. It makes the surface of the table or of the material level.

Good to know

• The machine was used on wood and thin aluminium.
• The repository holds the images and the Fusion 360 example, Example.f3d, and is under the MIT licence.
• Wear eye and ear protection and dust extraction when you cut, and never leave the machine alone while it runs.

The project is in the CNC-3018-PRO repository on GitHub.