Frequently Asked Questions

CNC (Computer Numerical Control) machining is a subtractive manufacturing process that produces parts by cutting material away from a solid block using computer-controlled machines. It’s ideal for producing accurate, functional parts in a wide range of materials.

Numerous types of metal and plastic material can be machined using CNC machining. We keep a stock of commonly used materials in-house, including:

• Aluminium alloy 6082
• Stainless steel, AISI grade 304
• Stainless steel, AISI grade 316
• Acetal (Delrin)
• Acrylic (PMMA)

Other materials are available quickly from our suppliers including a large array of different engineering plastics. If you’re unsure which material is best, our team can advise based on performance, finish and function.

CNC machining is well-suited to parts that need high accuracy, excellent surface finishes or strength in production-grade materials. 3D printing is often used for complex geometries and rapid turnaround, while CNC machining delivers precision parts with robust mechanical properties.

Our general quoted tolerance is ±0.1mm. In reality, CNC machining is usually accurate to much less than ±0.1mm, and critical dimensions can be held to tight tolerances depending on the material and geometry. We always check your drawings and requirements before machining.

For our low volume production work and 3-day production work, we typically use our 5-axis VMCs. These machines are configured to handle two main billet sizes: 150mm x 100mm x 90mm and 150mm x 50mm x 40mm. However, we can accommodate smaller parts with a range of billet sizes available.

We also have a wide array of 3-axis machines which can produce parts up to approximately 450 x 350 x 150 mm, subject to geometry. See our Plant List for full details.

If in doubt, it’s best to speak to us about your specific needs.

We typically offer flexible production speeds for CNC parts, depending on part complexity and quantity, as well as our capacity at the time. Timescales will be confirmed as part of the quotation / ordering process.

While we do not offer in-house plating and anodising services, we do have a sub-contractor that we work closely with to ensure you receive the finish you are looking for. Common requests are black, clear and hard anodising, surtec 650 and nickel plating. Other finishes are available on request just contact us on 01763 249760 for more information.

Vapour honing is a type of finishing that can be applied to parts after the machining process to both clean and provide a more uniform surface finish. It is a technology that involves blasting the part with a mix of abrasive material and pressurised water. It is effectively a ‘wet’ version of dry blasting however the water softens the blow of the material and washes dirt and debris away.

We vapour hone CNC machined parts as standard unless instructed not to, or it is not suitable for your part.

Yes, we can machine free issue material. This is dependent on part geometry and material, but please contact us to discuss your needs.

Browse our finishing options.

Yes. Our CNC expertise underpins not only the production of standalone parts, but also the manufacture of mould tooling for our injection moulding service. This gives us complete control over tool accuracy, timescales and modifications.

We provide CNC machining for clients in medical, aerospace, automotive, consumer products and more — for both prototypes and production-quality parts.

CNC turning rotates the material on a spindle while a cutting tool removes material to create cylindrical parts. It’s perfect for shafts, pins, and other round or symmetrical components.

CNC turning is most effective for:

• Shafts and spacers
• Bushings and housings
• Threaded components
• Cylindrical parts with precise dimensions

We routinely achieve ±0.05 mm or better in CNC turning, ensuring a precise fit for assemblies.

We typically offer flexible production speeds for CNC parts, depending on part complexity and quantity, as well as our capacity at the time. Timescales will be confirmed as part of the quotation / ordering process.

SLS (Selective Laser Sintering) is a powder-based 3D printing process that uses a laser to fuse layers of nylon material together to create functional prototypes and production parts. It is well-suited to complex geometries, lightweight structures and parts that need strength and durability.

SLS is widely used for functional prototypes, jigs and fixtures, and end-use parts. Its ability to produce complex shapes without the need for support structures makes it ideal for lightweight components, housings, enclosures and assemblies. Because SLS parts are strong and durable, the process is also well-suited to low volume production runs.

Absolutely. SLS parts possess mechanical properties suitable for end-use applications, including high strength, durability, and thermal resistance. They are often used in functional components, housings, and assemblies that require long-term performance.

SLS vs. SLA: While SLA offers superior surface finish and detail, SLS provides better mechanical properties and doesn’t require support structures.

SLS vs. DLP: DLP is faster for small parts with fine details, but SLS is more suitable for larger, functional parts with complex geometries.

SLS is widely used across various industries, including:

• Automotive: For prototyping and producing durable components.
• Medical: Creating custom prosthetics and anatomical models.
• Consumer Goods: Manufacturing complex and customized products.
• Aerospace: Producing lightweight and strong parts for aircraft and spacecraft.

SLS commonly utilises thermoplastic polymers like Nylon 12 (PA12), known for its strength, durability, and thermal resistance.

We offer Matrix PA12 CR – a carbon reduced nylon. To learn more about Matrix PA12 CR, visit our Materials Datasheets page.

SLS is very versatile, but we recommend a minimum wall thickness of 0.7 mm for rigid parts and 1 mm for larger components. Features such as snap-fits, clips and living hinges are possible, but it’s always best to check your design with our team if you’re unsure. We can advise on adjustments to optimise strength, detail and finish.

We offer a range of production speeds to suit your project needs. SLS 3D printed parts can be delivered via our Overnight service, or you can choose from 3, 7, or 12 working day turnaround options depending on your timescales and budget.

Yes. Our online Matrix system allows you to upload your files, get an instant quote and place your order directly for SLS 3D printed parts (as well as for SLA and DLP parts). You can also select your required production speed and finishing options, making it quick and simple to manage your projects.

DLP (Digital Light Processing) 3D printing is a resin-based process that uses a projector to cure entire layers of liquid resin at once. This makes it faster than SLA while still delivering excellent accuracy and fine details. It’s particularly well suited to small, highly detailed parts such as medical devices, micro components, and intricate prototypes.

DLP is fast, accurate, and excellent for highly detailed designs. It is particularly useful for projects where surface finish, resolution, and speed are equally important.

DLP is best for small, detailed parts rather than large models. While surface quality is excellent, parts are generally less strong than those produced with SLS or CNC machining.

DLP is widely used for applications such as microfluidics, dental and medical models, and intricate prototypes in consumer and industrial product design. Its speed and fine detail make it ideal where time-to-market is critical.

We offer a range of resins for DLP, each suited to different applications, from clear and rigid resins to those with enhanced mechanical properties. The best material will depend on whether your part needs optical clarity, strength, flexibility, or fine surface finish.

DLP and SLA are both resin-based technologies with excellent detail and surface finish, but DLP is generally faster for small parts as it cures entire layers at once. SLS, on the other hand, uses nylon powder to create stronger and more durable parts but with a slightly rougher surface finish. The best choice depends on whether speed, detail, or strength is your priority.

DLP parts can be produced with very fine resolution, with feature sizes down to around 50 microns. To achieve the best results, small features should have a minimum wall thickness of 0.5 mm, while larger sections should be at least 1 mm.

Because DLP builds upside down, each layer is cured against a clear membrane and then lifted before being recoated with resin. This process means that thicker wall sections (over 5 mm) can increase surface tension and the effects of gravity, raising the risk of print failure. To counter this, additional or stronger supports are often required, which can leave more witness marks than SLA.

In general, if a part has been designed for injection moulding, it is likely to be suitable for DLP.

Our team can provide guidance on optimising designs for DLP to achieve both strength and accuracy.

DLP parts can be supplied as-built or finished in-house. Finishing options include hand-sanding, painting, lacquering, and detailing to enhance appearance or functionality.

DLP parts are typically used for prototypes and detailed models, but some resins are suitable for short-term functional testing. For more durable, load-bearing parts, SLS or CNC machining may be more appropriate.

Yes. DLP is often used for producing small batches of components, particularly where detail, accuracy, and speed are important.

Filament 3D printing uses a spool of thermoplastic material that is melted and deposited layer by layer to build a part. At Prototype Projects, we use a Bambu Lab X1 Carbon printer to produce robust, cost-effective prototypes, ideal for early-stage design validation.

We stock Matrix ABS and Matrix PLA for our Filament 3D Printing service.

From our supplier, we are also able to quickly source PLA, ABS, PETG, ASA/ABS, PC/TPU, PA/PET, PPS and Fibre Reinforced.

Filament 3D printing is ideal for early concept models, jigs and fixtures, or functional parts where aesthetics are less critical. It offers excellent value for rapid prototyping, particularly when turnaround and cost are key factors.

SLS delivers stronger, production-like nylon parts, making it better for functional testing.

SLA and DLP offer finer detail and smoother finishes, which are often required for presentation models or assemblies with tight tolerances.

Filament printing is more accessible and cost-effective for basic prototypes, though it is not suitable for highly detailed or high-precision components.

Using our Bambu Lab X1 Carbon printer, we achieve good dimensional accuracy and surface finish for a filament-based process. However, if your part requires very fine features or complex geometries, one of our resin-based processes (SLA or DLP) may be more suitable.

Yes, depending on the material used. PETG, ABS and TPU are often chosen for their mechanical properties. If you need guidance on material selection, our team is happy to advise based on your requirements.

We produce a wide range of models including concept models, display models, architectural models, engineering models, and highly detailed presentation models. Whether you need a one-off showcase piece or a functional model to demonstrate design features, our team can bring your ideas to life.

Our model makers use a variety of materials depending on your requirements, including resins, plastics, foams, wood, metals and 3D printed parts. By combining traditional craftsmanship with advanced prototyping techniques, we can achieve the right balance of strength, detail, and finish.

Yes. Our in-house finishing team can hand-paint, spray-finish or detail your models to match branding, colours and textures. We can also apply surface textures, decals, and logos to ensure the final model is presentation-ready. In our early days as model makers, many of the models we produced were photographed for use in catalogues, so creating visually flawless, highly detailed models has always been part of our expertise.

Absolutely. Many of our models incorporate 3D printed or CNC machined components to achieve fine detail or functional accuracy. This hybrid approach gives you the best of both worlds: handcrafted quality combined with the precision of digital manufacturing.

We work across a wide range of industries, including medical, automotive, aerospace, consumer products, architecture, and marketing. Models are often used for product launches, exhibitions, investor presentations, and internal design reviews.

Our models are highly accurate to the CAD data or sketches provided. Depending on your needs, we can create realistic replicas or simplified versions to highlight key features.

Every model is unique, and timescales vary depending on complexity, size and finishing requirements. We’ll discuss your project and confirm a timescale when we provide your quote.

Yes. Where required, we can build models with working features, moving parts, or lighting. This is particularly useful for demonstrations and trade shows.

Yes. We frequently produce models for clients developing new products and understand the importance of confidentiality. We’re happy to sign NDAs to give you complete peace of mind.