Now is an opportune time to focus on design manufacturability to help set your business up for future success.
The current state of the world can be quite overwhelming right now. There is a lot of uncertainty especially for business owners. Despite worldwide efforts to contain the new coronavirus, hotspots continue to emerge, and the number of cases is on the rise.
It has only been a couple of months since the coronavirus made its first public appearance in Wuhan, China. Since then, the virus has hopped borders and a growing number of people have been infected. The current state of the world is now officially affecting the economy and businesses everywhere. Where does that leave you? What can you do in this unusual time to help your business continue to grow?
At RCI, we see the current state as an opportunity to focus on a design or idea you perhaps have been sitting on and learn how to make it manufacturable. Reflector manufacturability must be carefully considered to avoid performance blunders. We are the experts in making sure your part is manufacturable. Using our expert tips about material selection, manufacturing processes and assembly, you’ll be able to align your reflector design and manufacturability to produce exceptional results from concept through end-use.
When photometric requirements have been determined, there are three material-related decisions to make:
Thickness and Strength
• Choose materials that provide appropriate thickness and strength to support components
• UL or other code requirements may mandate using materials of a certain minimum thickness
• Use materials that are easily available in the desired thickness, strength and finish – you’ll save time and money
• Pay attention to the grain direction or pattern orientation of a specified finish
• Photometry with specific material orientation needs will impact the material selected and manufacturing process used
• Provides material stiffness
• Materials with an embossed or textured pattern will be structurally stronger than those that are flat
Much like design, manufacturing offers a variety of options. Choosing the appropriate manufacturing method for your application depends on a number of factors related to the properties of each process.
Die cutting refers to building hard tooling from steel for custom part creation.
Blanking refers to punching a flat piece part with no holes (the “blank”) out of a raw stock based on the die cut of the outside shape of the part. Blanking is an effective way to cut down large sheets or coils of stock and prepare parts for hard tooling, CNC turret punch pressing, CNC laser cutting or a combination of these processes.
Using custom hard tooling built from steel, a pierce die punches internal features, like round or shaped holes, into parts pre-cut by a blank die. If blanking and piercing are used simultaneously to manufacture parts, the process is commonly referred to as “pierce and blank” die cutting. Pierce and blank die cutting allows for excellent materials utilization and the lowest piece part cost for production, but:
• There is higher startup cost and time investment because of tool design, build and testing needs
• Tooling is not easily revised or changed, although once properly completed order turnaround time is very fast and consistent
Punching and Laser Cutting
Punching and laser cutting use computer numerical control (CNC) programming that eliminates the time and expense associated with specialized hard tooling. The processes are ideal for rapid prototyping or low-volume production.
CNC Turret Punch Pressing
A typical CNC turret punch is comprised of two “turrets” that simulate the actions of a standard punch and die. Each turret offers a selection of up to 60 standard punch tools to create holes of varying sizes, straight edges, common notches and mounting holes, and a variety of complex shapes. Once chosen, the tool is placed in punching position and cut using computer precision-synchronization to align the turrets. CNC turret punch pressing requires minimal startup cost to begin production:
• Once the part is programmed and special punches are prepared, production can start immediately for fast turnaround • Lower volume production can be completed at a reasonable piece part cost
• Program changes are simple, so the part can be easily revised or changed
• Materials utilization is excellent, but some waste is created because of the clamping area required for proper holding during processing
CNC Laser Cutting
As the name suggests, laser cutting uses computer programming and optics technologies to direct a high-power laser to melt, burn or otherwise vaporize patterns into flat-sheet stock. The process is more flexible and often faster than turret punching, and can easily accommodate compound and complex designs.
CNC laser cutting is especially advantageous for prototyping and small quantity runs due to:
• Quick startup lead times and minimal startup costs
• Fast turnaround times due to simple program changes for easy part revisions or changes
• Reasonable piece part cost • Exceptional materials utilization
The continuous bending of sheet metal on rollers, particularly thin stock, is not an exact process. Parts will have some variation in shape and may require assembly methods to hold correct shape. There are four basic rolling techniques:
1. Hand rolling forms straight stock into a single radius form of approximately .75” (19 mm) or larger.
2. Cone rolling produces conic shapes with small openings of about .250” and depths not exceeding 11”. The reflective surface can be on the inside or outside.
3. Radii rolling can blend multiple forms into one pass for fabricators that typically cost less than those made with a series of faceted forms. 4. Parabolic and complex shapes rolling creates complex curves in one pass.
Using a brake press with standard utility or special tooling is the most economical way to create multiple bends in one process with:
• Sharp bends up to approximately .625” radius • High quality and accuracy • Fast turnaround times • Easy changes and revisions
Stretching, bending and punching metal over press-mounted dies provides quality options for long and short part runs.
Steel form dies are exactly that – dies made from steel that have a long life and deliver consistent, high quality forms. Once tooled, steel form dies offer faster order turnaround times but:
• The startup tooling cost investment is higher
• There is significant lead time required to design and build hard tooling
• Forms are not easily revised or changed
Temporary tooling is a short-term, economical solution for prototypes and short-run product. Unlike steel form dies, temporary tools:
• Have a short lifespan that can reliably produce only a small number of forms, from a handful to several thousand pieces
• Can compromise quality depending on the geometry, materials and type of temporary tool
• Are not intended for complex shapes
• Have relatively short lead and turnaround times
• Can be revised or changed for moderate cost
In progressive tooling, a metal strip is formed into a finished part using several individual workstations that perform one or more operations on the part. The part remains attached to a stock strip as it passes through each station and is cut off in the final operation. Progressive tooling combines processes for exceptionally high quality parts and very fast runaround time, but:
• The startup costs and lead time to design and build hard tooling is significant
• Forms are not easily revised or changed
• It is not economically feasible for parts that exceed a maximum dimension of approximately 12” (305 mm) unless extremely high volume production is needed
Rivets, tabs, adhesives, welding and tension assemblies are all viable final production methods, but each has unique properties that may impact fit, finish and performance.
Rivets require material overlap and holes through which the rivets pass.
• Are used in difficult to reach areas as they can be placed by hand and only require access from one side to install
• Protrude from the material, with the tail extending out at least 1/8” (3.2 mm), depending on the exact rivet specifications
• Are noticeable on a reflective finish and create an unattractive appearance
• Are machine-installed for uniformity and fast placement
• Are less expensive than pop rivets • Minimally protrude from material surfaces, usually less than .030” (.75 mm), and the head and tail have equal projection
• Don’t impede the finish appearance
Tabs are less visible than rivets, and can be easily hand-assembled.
• Are two opposing hook-shaped tabs used to join adjacent parts at shallow angles
• Typically interlock common pieces that repeat in an assembly, such as a bowl shape made from multiple wedges
• Are two opposing tabs that are either adjacent or nest within each other and are folded over after assembly
• Join materials without extending beyond edges
Tab and slot configurations
• Are the most common attachments for thin materials
• Join materials by passing a tab on the corner of one adjacent part through the corresponding slot on another, then melting or twisting the tab in place to lock the parts together
• Remain strong
• Are the easiest and simplest to incorporate into the assembly process
Adhesive tapes and sealants require no physical manipulation of the fabricator components.
VHB and Transfer Tape
• Offer the convenience of double-sided adhesion of various thicknesses to join two surface areas
• Can be used where the visual appearance or function of the fabricator cannot tolerate holes or tabs
• Bond strongly, but do not tolerate temperatures exceeding 200°F
• Are expensive compared to tabs and welding, and are also time-consuming to apply
• Can be applied to fill gaps that otherwise allow light leaks or foreign debris intrusion into the reflective cavity
• Generally tolerate temperatures in excess of 1300°F
• Are commonly available in black or clear color choices
Welding Specialized for joining the edges of very thin materials, welding
• Effectively closes and holds conic and other shapes • Has limited strength due to small weld areas
• Occasionally causes small defects in surface finishes at weld points
Some parts are designed to be “open” or “closed” when loose, in order to properly tension the assembly when put together. Tension assemblies ensure all parts configure and hold the desired final shape.
Let us help you with your design and make it manufacturable. Our professional reflector specialists are here to help! Call 866.276.6242 or contact us to request a Free Manufacturability Assessment.