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Frequently Asked Questions
Frequently Asked Questions
Here you’ll find answers to the most frequently asked questions we receive from our clients. If you have a question that isn’t answered here, please contact us.
Quotes and ordering
We offer an express, next day dispatch service on SLS, SLA, Polyjet and DLP parts. All final data is required by 4.00pm for express delivery.
We offer these service levels on 3D printed parts:
- Express: Next day dispatch* (if quoted before 4pm and ordered before 5.00pm)
- Standard: in 3 working days
- Economy: in 8 working days
All lead times are dependent on part size and actual build time on the specified RP machine and will be confirmed upon order placement.
Please specify service level and finish level when requesting a quote.
Quote requests received without service level or finish specification will be quoted as express service and basic finish.
All final data is required by 4.00pm for Express delivery.
We offer various finishing levels on SLA, SLS, Polyjet and DLP parts, ranging from a basic finish level, a standard finish level, to a detailed finish level. Click here to find out more about our finishing levels.
Quote requests received between 8.00am and 4.00pm are usually responded to on the same day, depending on the complexity of the requirement. Requests received after 4.00pm will be responded to on the following business day.
For local clients requiring delivery within a 15-mile radius of Royston, Prototype Projects offers a free delivery service using our own vehicles.
For clients requiring delivery outside the 15-mile radius of Royston, delivery will be via Royal Mail guaranteed before 1.00pm service or equivalent, for which there is a charge.
SLS (Selective Laser Sintering)
SLS is an additive manufacturing/3D printing process for rapid prototyping and production of 3D parts with complex shapes and geometries:
- Speed: fast turnaround depending on size and detail requirements
- High accuracy: parts can closely mimic the properties of finished parts
- Complexity: highly complex shapes can be achieved
Most parts are currently made in engineering plastic, most commonly in Nylon (PA12), a synthetic thermoplastic polymer which offers excellent dimensional stability as well as high levels of wear and chemical resistance. Other materials are available, however – see our materials page.
- Isotropic mechanical properties: SLS is a process consisting of a build-up of multiple bonded layers of material (hence the term additive manufacturing) resulting in a part of extraordinary strength and isotropic mechanical properties, making it ideal for the production of functional parts and prototypes.
- Stiffness: If a high level of part stiffness is required, the part must be designed and printed fully solid.
Typical mechanical properties of SLS printed using PA12 are:
| X-Y Direction | Z Direction | |
| Tensile strength | 48 MPa | 42 MPa |
| Tensile modulus | 1650 MPa | 1650 MPa |
| Elongation at break | 18% | 4% |
SLS parts with large flat surfaces may warp, though this can be avoided to a degree by the prototyping engineer. Design engineers can mitigate the effects of warping by reducing part volume.
Escape holes must be designed into SLS parts to allow for the removal of excess (unsintered) powder from inside the part. Ideally each part should have two escape holes.
Various post-processing (or finishing) options can be applied to SLS parts to improve aesthetics, surface smoothness and part functionality. Finishing processes include polishing, dyeing, spray painting and lacquering, as well as improving functionality of the part using a range of coatings.
Using technology from Munich-based specialists DyeMansion, we offer a consistent and repeatable SLS dyeing service. This end-to-end SLS finishing solution offers a high-quality finish with the option to have your SLS parts coloured to exact requirements.
Including Black, which is our standard colour that is run every day, we stock 17 standard colours.
An entire RAL classics palette has also been developed for polyamide 12 (PA2200) parts produced by SLS.
Yes. As well as colouring parts we make for you, we can also dye SLS parts that you have made yourself or had made elsewhere. Contact us to find out more about our contract colouring service and to ask about pricing
Yes. Using our specialist graining process, SLS and SLA parts can be textured, for example giving them the look of leather or other natural materials.
SLS can be used to produce many functional features including axles, threads, tanks and hinges. Achievable complex geometries include undercuts, negative draft and interior features.
Every Additive Manufacturing 3D printing technology has its own distinct benefits and for this reason it is not always easy to provide a like for like comparison.
As an expert prototyping bureau, our is to help every client select the most appropriate prototyping or additive manufacturing process for their specific projects requirements. Your requirements will be determined by:
- The stage you’re at in your product development process
- The properties, functions and purpose of the final part which will, in turn, determine the material to be used
- The speed with which your prototype part is required.
We offer these service levels for 3D printed parts:
- Express: next working day dispatch (not available for SLS parts that have been dyed)
- Standard: in 3 working days
- Economy: in 8 working days
SLA (Stereolithography)
Stereolithography, or SLA rapid prototyping, is a 3D printing technology used for rapid prototyping and additive manufacturing. As one of the most popular and versatile technologies offered by Prototype Projects, concept models, one-off presentation models and masters for use in Vacuum Casting are often produced using SLA technology.
We use a range of Accura materials for SLA parts. Please refer to our materials page to see which materials we currently offer and their respective properties.
One of the main benefits of SLA is speed. Depending on exact requirements, SLA parts can be printed overnight for next day dispatch. The high level of detail realised with SLA is another benefit. It is also a cost effective technology where single parts can be produced quickly and easily.
Yes. Using our specialist graining process, SLS and SLA parts can be textured, for example giving them the look of leather or other natural materials.
Various post-processing (or finishing) options can be applied to SLA parts to improve aesthetics, surface smoothness and part functionality. Finishing processes include polishing, dyeing, spray painting and lacquering, as well as improving functionality of the part using a range of coatings.
Yes. We run an SLA machine in our dedicated medical devices area using 3D Systems’ Accura ClearVue material.
The Projets we use have an Ultra High Definition build mode, delivering fine feature parts via a dual spot laser, as standard. The terms ‘Normal Res’ and ‘Hi Res’, therefore, are no longer relevant for 99% of builds.The dual spot intelligent scanning laser is adjusted automatically to suit the geometry being printed. This applies to the whole bed size:
- Projet 6000: 250x250x250
- Projet 7000: 380x380x250
Both machines deliver fine point scanning for borders and small features and, broader scanning for infill hatching for each layer (slice):
- Fine feature: down to 75 μm (0.003 in)
- Larger feature: 750 μm (0.030 in)
Every Additive Manufacturing 3D printing technology has its own distinct benefits and for this reason it is not always easy to provide a like for like comparison.
As an expert prototyping bureau, our is to help every client select the most appropriate prototyping or additive manufacturing process for their specific projects requirements. Your requirements will be determined by:
- The stage you’re at in your product development process
- The properties, functions and purpose of the final part which will, in turn, determine the material to be used
- The speed with which your prototype part is required.
We offer these service levels for 3D printed parts:
- Express: next working day dispatch
- Standard: in 3 working days
- Economy: in 8 working days
Polyjet
The Polyjet 3D printing process is unique among 3D printing technologies for its range of complex printers which are capable of using multiple materials simultaneously to build a single part.
The Polyjet materials we offer allow us to offer parts with the following properties:
- Rigid opaque
- Transparent
- Simulated polypropylene
- Rubber-like – Shore A 30 > 95
Each part is manufactured with either a primary material or a primary and secondary material.
Where two materials are used, they are mixed to generate different levels of tensile strength, elasticity, flexural strength and temperature durability.
Limited post-processing (or finishing) options can be applied to Polyjet parts. Visit our finishing page for full details.
Polyjet offers a broad range of part properties:
- Rigid to flexible properties
- Thermal resistance
- High level of feature complexity
- Smooth surface finish
- Ultra-thin layers ideal for overprinting
- Parts can be drilled and tapped, sanded and painted
We offer these service levels for 3D printed parts:
- Express: next working day dispatch
- Standard: in 3 working days
- Economy: in 8 working days
DLP
DLP is a 3D-printing technology which is ideal for functional prototyping and very low volume production. It delivers an ultra-high print speed along with quality and accuracy meaning we can print your prototypes quickly while maintaining quality and accuracy.
We stock a number of materials for DLP. Additional materials are also available upon request. Visit the DLP page to find out what materials we currently stock.
A number of finishing options are available for DLP parts, such as applying a primer coat and surface painting. Visit our finishing page for full details.
DLP delivers high quality surface quality at 65 microns. It is possible to texture the surface of these parts in much the same way as the surface of SLS and SLA parts can be textured.
DLP is most suited to small prototype parts:
- Build area: 124.8 x 70.2 x 196 mm
- XY Pixel Pitch (resolution): 65 microns
- Layer thickness: 10-100 microns (material dependent)
- Light wavelength: 405 nm
We offer these service levels for 3D printed parts:
- Express: next working day dispatch
- Standard: in 3 working days
- Economy: in 8 working days
CNC machining
CNC machining is used to produce incredibly accurate, high-quality parts with an excellent finish.
The CNC services we offer mean prototype tools can be injected in-house and production tools can be run by our subcontractors or supplied to you for moulding. We can also provide a full range of tool refurbishment.
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
Other materials are available quickly from our suppliers.
We offer three service levels for CNC machining. Express (3 working days) – subject to criteria, Standard (7 working days) and Economy (12 working days) (.
Vacuum Casting
Vacuum Casting is used for producing small numbers of highly accurate polyurethane prototype parts with characteristics and quality comparable to the final product.
We can produce parts to extremely fine levels of detail and keep concessions to the absolute minimum.
It depends on the material being used but generally a tool can produce 20-25 parts. This number can be affected by the geometry of the part and the PU material being used.
- ABS
- POM
- Elastomers (Range: 25 – 95 Shore A)
- Nylon including glass filled
- Polypropylene
- Maximum casting weight: 1400 g
- Maximum mould size: 450 x 470 x 400 mm
The service level for Vacuum Cast parts is confirmed upon quotation and placement of order.
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