Building a CNC milling machine is one of the most ambitious and rewarding projects for a maker. Unlike 3D printers, a CNC requires more robust components because it has to handle the cutting forces when machining wood, plastic, composites and aluminium. Extruded aluminium profiles are the ideal base for the structure: light, rigid, modular and easy to assemble.
In this guide we look at all the components required to build a hobby CNC, with details of the products available in the DHM-online catalogue.
1. Structure: extruded aluminium profiles
The structure is the foundation of the machine and determines rigidity, precision and maximum machinable dimensions. For a hobby CNC, we recommend 6-series profiles (8 mm slot) with 30×30 or 30×60 mm sections for smaller machines (working area up to 400×400 mm), and 8-series profiles (10 mm slot) with 40×40, 40×80 or 45×45 mm sections for larger machines or machines that need to process aluminium. The 5-series (6 mm slot) with 20×20 profiles is too light for a CNC: it is fine for 3D printers but not for handling cutting forces.
At DHM-online, profiles are available with a cut-to-length service, which greatly simplifies construction.
2. Guides and linear movement
For X and Y axes, linear recirculating ball bearing slides (type HGR15 or HGR20) are the optimal choice for precision and rigidity. For smaller budget projects, SBR16 or SBR20 guides offer a good compromise. For the Z-axis, MGN12 or HGR15 linear guides are sufficient, as the forces are mainly axial and handled by the screw.
3. Transmission of motion
For the X and Y axes, the options are SFU1605 or SFU2005 ball screws for maximum precision and zero backlash, or the rack and pinion combination for very long strokes (over 1 metre). For the Z axis, an SFU1605 recirculating screw is standard. Trapezoidal screws (type Tr8×8) are an inexpensive alternative but with higher friction and possible backlash.
4. Motors and driver
For a CNC that has to mill solid materials, motors NEMA 23 are the standard choice, with torques from 1.2 to 3.0 Nm depending on the size of the machine and the materials to be machined. The driver DM542 or equivalent (24-48V, up to 4.2A) offer adequate performance. For smaller machines that will only process wood and plastic, NEMA 17 long (48-60 mm) may be sufficient with driver TMC5160.
5. Control board
The most popular options are Duet3D boards (Duet 3 6HC or 6XD for maximum flexibility and the 6XD's opto-isolated IOs designed for CNC applications), GRBL controllers on Arduino (cheap solution but limited to 3 axes), and Raspberry Pi -based controllers with LinuxCNC or GRBL_ESP32. At DHM-online you will find boards Duet3D, Arduino, Raspberry Pi and all necessary accessories.
6. Spindle
The spindle is the component that turns the cutting tool. The main options are the trim router type Makita RT0701 or Kress (inexpensive, 500-800W, up to 30,000 RPM, noisy), the VFD spindle with inverter (professional, 800-2200W, variable speed, silent, air or water cooling), and the Dremel/rotary tool (only for very soft materials and engraving).
7. Screws and fasteners
A CNC requires significant amounts of fasteners: M5 and M6 cylinder head screws for profile fastening, T-nuts for profile slots, M3 and M4 screws for mounting electronic components, grub screws for attaching pulleys and couplings to shafts, and angle brackets and splice plates for structural connections.
8. Electronics and Wiring
In addition to the control board, a switching power supply 24V or 48V sized for motors and spindle, mechanical or inductive limit switches for all axes, an emergency stop button (E-stop), wiring with appropriate connectors and cable chains to protect moving cables are required.
Indicative budget
|
Component |
Indicative budget |
|
Aluminium profiles (structure) |
€ 100-250 |
|
Linear guides + brackets |
€ 100-300 |
|
Ball screws |
€ 80-200 |
|
Motors NEMA 23 (×3-4) |
€ 60-120 |
|
Driver stepper (×3-4) |
€ 40-100 |
|
Control board |
€ 50-250 |
|
Spindle + inverter |
€ 80-300 |
|
Power supply |
€ 30-80 |
|
Screws and accessories |
€ 50-100 |
|
Miscellaneous electronics |
€ 30-80 |
|
APPROXIMATE TOTAL |
€ 600-1800 |
All components at DHM-online
At DHM-online you will find all the components you need to build your CNC: aluminium profiles cut to size, linear and SBR guides, recirculating and trapezoidal screws, motors NEMA 17 and NEMA 23, driver stepper , boards Duet3D and Arduino, power supplies, screws, connectors and wiring.
One supplier for the entire project.
