• CNC Milling 1500x800x800mm 
• CNC Turning Ø800x1000mm

Maximum part size depends on your machine size; giant machines can produce parts bigger than 2mx0.8mx1m, five-axis CNC machines have a smaller volume.

• Metals: Minimum 0.8mm Plastics: Minimum 1.5mm
• Absolute minimum 0.6mm

Thin walls on a part allow for more opportunity to break, no matter what the material. Wall thickness is proportional to the stiffness of the material, so thinner wall thickness leads to vibrations when machining. As a guideline, keep this in mind: for metals, try not to go below 0.8mm, and plastics not less than 1.5mm. Try to design your part from sheet metal instead or use another manufacturing method if required.

• Typically Maximum: 4 x part length

Vibration becomes a problem when machining tall features. Try to work by the ratio of max height is 4 x the length to minimize machine vibrations.

• Standard: ±0.125mm
• Minimum: ±0.001mm

Tolerances are necessary for a design; excess tolerancing only increases machining time and cost. Tight tolerances should only be specified where essential and should keep with the CNC machines tolerance ability. Some standard tolerance to stick by for most CNC machines is ±0.125mm, whereas down to ±0.001mm is feasible. Tolerances should be defined on all critical features.

• Maximum: Hole length = 4x Hole diameter

Try to work with the ratio hole diameter is less than 4 x the length of the hole. If the hole is too deep, this results in the tool deflecting and makes it difficult to remove the chips, leading to tool fracture. An example is a hole 10mm wide that should not be more than 40 mm deep. Deeper holes need to be machined with larger diameter cutting tools; bear this in mind.

• Maximum thread length=3 x hole diameter
• Recommended: M6 or higher
• Smallest: around M2

Strong threads are formed in the first few turns, so long threads are pretty unnecessary; as a rule of thumb, try to design your thread three times longer than the hole diameter. Choose larger threads if possible; they are easier to machine.

Not all features can be machined on a CNC. If one sticks to some simple guidelines when designing, the part will be redesigned before machining.

One needs to understand the machine’s capability; for example, A 3 axis machine cannot machine negative angles. Another example is one cannot machine curved holes on a CNC; to do this, one would have to split the part into two and reattach the two halves. EDM is a better process for this.

When designing, try to think about the machining processes involved in creating the part; one needs to think practically about how the machine will move and if the part is to be machined on a three-axis or five-axis machine. Three-axis machines can only work with simple geometry and curves, whereas five-axis machines can manage more complex parts.

• Minimum: 2.5mm
• Smallest: 0.100 mm

Most CNC machines use a minimum of a 2.5mm tool diameter; this can be considered when designing. It is feasible to develop features smaller than 0.1mm, although this should be avoided.

One needs to think of the surfaces that can be machined with the CNC tool, internal geometries such as a curved hole are impossible to machine, and such a part would need to be split into two separate parts machined separately and then combined to produce that geometry.

The vertical parts of a machined part will always have a radius due to the tool geometry – drills are always round and can only cut radii.

The geometry of the part decides how it is held in the CNC machine; this impacts the cost; if it can’t be bolted down, it would need to be clamped in place, which could add to a positional error when completing subsequent runs.

Workpiece stiffness can change when thin walls are machined into the parts leading to the vibration of the part. Take this into account when designing.

Read Geomiq’s CNC Design Guide > 

CNC (Computer Numerical Control) machining is a manufacturing process where computerized systems control the movement of cutting tools to shape and cut materials with precision. The process starts with creating a digital design or CAD (Computer-Aided Design) model, which is then converted into machine-readable instructions. These instructions guide the CNC machine in accurately cutting, drilling, milling, or turning the material to create the desired shape.

CNC (Computer Numerical Control) machining is a manufacturing process where computerized systems control the movement of cutting tools to shape and cut materials with precision. The process starts with creating a digital design or CAD (Computer-Aided Design) model, which is then converted into machine-readable instructions. These instructions guide the CNC machine in accurately cutting, drilling, milling, or turning the material to create the desired shape.

CNC machining services are widely used in various industries, including aerospace, automotive, electronics, medical, engineering, prototyping, and manufacturing. These industries rely on CNC machining for precise and efficient production of parts and components.

CNC machining is known for its high accuracy and precision. Modern CNC machines can achieve very tight tolerances, typically ranging from a few micrometers to a few hundredths of a millimeter, depending on the machine and the specific requirements of the project.

Yes, CNC machining is capable of producing complex and intricate designs with great precision. The ability to program the movements of the cutting tools allows CNC machines to create intricate geometries, cavities, undercuts, and fine details that may be challenging or impossible with traditional machining methods.

When selecting a CNC machining service provider in the UK, consider factors such as their experience, expertise, reputation, capabilities, equipment quality, turnaround time, pricing, and customer reviews. Look for companies with a proven track record, certifications, and a commitment to quality control to ensure reliable and consistent results.

Common CNC machining services include milling, turning, drilling, grinding, and EDM (Electrical Discharge Machining). These services cater to a wide range of applications and materials, such as metal, plastic, wood, composites, and more.

Yes, CNC machining services can accommodate both small and large production runs. CNC machines are highly versatile and can be programmed to produce a single prototype or thousands of identical parts with consistent quality and precision.

The CNC machining process typically involves the following steps:

• Designing the part using CAD software.
• Converting the design into machine-readable instructions (G-code).
• Setting up the CNC machine, including securing the material and loading the necessary tools.
• Preparing the CNC program and transferring it to the machine.
• Running the program and monitoring the machining process.
• Inspecting the finished part for quality and accuracy.