During the Automotive lighting prototype development and manufacturing process, some key components are very critical for the quality of the final prototype, because these components have different function requirements from the design point of view of the automotive lighting. So how to make the prototype function as a molded part? Today, as the leading Automotive Lighting Prototype supplier in China, KUSLA will share the experience of how we make these 5 critical components for only one function prototype.
Bi-Color Outer lens
An outer lens is used to protect the lighting lamp’s internal components and lets the lights from the light source pass through to light the road. The design material is commonly clear PC for headlights and acrylic(PMMA) for taillights. To make the prototype of the outer lens, we took the following actions to make it right.
Use PMMA as the prototype material
We Choose Acrylic(PMMA) both for headlights and taillights. this is because high transparency as molded parts is the top need for the prototype, Acrylic sheets can fulfill this need with mirror polishing. Polycarbonate sheets are hard to polish and their transparency is not as good as acrylic.
Use CNC prototyping
CNC machining can get a high precision result to get the accurate surface of the design, Although 3D Printing also prints clear material but still can not achieve the level of acrylic after mirror polishing.
Make Two colors separately
To make the outer lens prototype function as a molded part, make two color parts separately and then glue them together with invisible glue. some prototype suppliers use painting on a piece prototype, this is not a good way to make the bi-color outer lens.
Bi-color bezel
Here we talk about that kind of bezel which is composed of Milky white(or red) and black parts. the black part function as styling and the milky white material function as diffusing the lights from the light source to get a homogenous lit result. So based on the function analysis, in KUSLA, here is what we took to make the bi-color bezel.
Custom production material block for milky material
In most situations, there will be no available milky material block in the market, because the milky material designed by the lighting optic engineer is always new and only for injection molding, So to make the prototype function as mold parts, Custom the milky material block is a perfect solution to make it.
Use CNC prototyping
there sometimes are optic features on the milky white part that need high precision results, CNC machining can make it.
Reflector
A reflector with optic facets is a common design in automotive lighting to reflect the lights from the light source to the place where the optic engineer wants it to be. So precision of the reflector prototype is very critical to function as a design requirement. here we take the following action to make it.
Use aluminum as the material
Plastic is easy to deform during the CNC machining process, so to make the small facets of the reflector precisely, using aluminum as the prototype material is a good solution. this is because aluminum is much harder than plastic to keep the precision but still easy to machine with CNC prototyping. in addition, using a small radius CNC tool is also important to get accurate results. we use the R0.1mm tool for CNC machining aluminum.
Metallization without a base coat
A base coat could help with the metallization process but it will also change the surface of the optic facets of the reflector, which could lead to light distortion. So metallization without a base coat is needed for the aluminum reflector prototype.
light pipes
To get the best efficiency of the light transmission, optic engineers need to use optic grade PC materials such as PC LED 2245 for the design. In this case, when we make a light pipe prototype, we can use exactly the same optic-grade material as the design.
Custom optic grade PC material block
there will be no available material block for the optic grade PC material, So we purchase the pellet materials from suppliers such as Covestro and then customize the block with these pellet materials.
Use CNC machining
To get the best precision of the optic features on the light guide, CNC machining will be the best for making the light pipe prototype.
Module lens
LED module lens is used for High beams and low beams in the headlights. it reflects the lights very precisely by the micro-optics on the module lens. Usually, the Micro optics are very small, and sometimes, the accuracy of CNC machining can not achieve the requirements. So in KUSLA, we do it as below:
Use single-point diamond turning
Single-point diamond turning can get an ultra-precision optic prototype of the module lens. and no manual polishing is needed for the optic prototype. it can make the module lens micro-optics with very high precision, Surface roughness can reach 4 nm RMS.
Conclusion
Automotive Lighting Prototype requires professional skills to make it at a high-quality level, work with outstanding suppliers will save you time for communications and potential reworks. Contact KUSLA if you have any prototype needs for the Automotive Lighting project.
FAQ
What is the alternative to make the outer lens prototype?
Urethane casting is another method to make the outer lens prototype with high transparency, but it will require one master prototype made by CNC machining, So when you need more than one piece of outer lens prototype, you can consider the urethane casting process.
What is the lead time to make the automotive lighting prototype?
In KUSLA, we make automotive lighting prototypes in less than 10 days.