Prototyping is a great way to reduce the costs and reduce the risk of the product development process. However there are some limitations depending on the process chosen due to the difference in processing and materials. Another issue is that more often than not a product may go through many versions of prototypes only to find that further changes have to be done to the design before it can be manufactured or the part have not been designed to achieve the required 2nd operation. With our many years of manufacturing experience we can offer advice to help you avoid this happening to you.
Description of Rapid Prototyping Processes
This is a subtractive process i.e. material is removed from a block of material to leave the desired 3D shape. Due to the lower labour rates in China, CNC prototyping is the most popular of out of all the processes:
• General tolerances that can be achieved = +/- 0.1 mm (smaller tolerances may be achieved on request)
• Excellent surface finishes achievable. Parts can be polished to a high gloss.
• Wide range of production plastic and metal materials available including engineering materials such as PEEK, PEI (Ultem), PBT, Aluminium, glass filled nylons and plating grades of ABS. Please contact us for material availability.
• Materials with excellent clarity such as automotive lenses etc.
• Excellent detail can be achieved (0.2 mm)
• Small to large volume production capabilities.
• Wide range of 2nd operations possible (chrome plating, vacuum metallising, anodising, ultrasonic welding, screen printing, pad printing, hot stamping and painting).
• Some limitations on the part design. Please contact us for more information.
• Cannot machine soft materials.
- SLS: Additive manufacturing process that uses a high powered laser to fuse powdered material particles together one layer at a time to create the desired 3D shape. This process is excellent for mechanical function testing.
- SLA: Additive manufacturing process is similar to SLS although the parts are created by a UV laser and a vat of UV-curable photopolymer “resin”. Another difference is that support must be created to prevent the parts distorting due to gravity. These supports must be removed manually.
PU – Rapid plastic (Silicone tooling): The first step in the process is to create a detailed master in order to make the silicone tool. A wide range of material simulants may be used to mould up to 20 parts using the vacuum casting process.
Prototyping Process comparison chart:
|Characteristic||CNC||SLA||SLS||PU - Rapid Plastic (Silicone tooling)|
|Material selection||Large variety of production materials available. Soft materials cannot be processed||Simulate materials available (please contact us for more details)||Nylon and glass filled nylon.||PU materials (polyurethane) in durometers from Shore A 30 to A 95|
|Transparency||Clear (high polished to create lenses is possible)||Semi-transparency||Not available||Clear (lenses etc.)|
|Fine details||Very good||Good||Average||Very good|
|Tolerance (approx.)Tolerance (approx.)||Up to +/- 0.05 mm||Up to +/- 0.3 mm||Up to +/- 0.5 mm||Up to +/- 0.|