When considering a Contract Manufacturer for a Precision Sheet Metal Fabrication Process for a part to be fabricated out of sheet metal you need to know the processes available to understand how you will design your sheet metal fabricated part to be the most economic manufactured. Each process has its positives and negatives. Many fabricators will force feed you what is easier for them not necessarily what is the best for your product in quality and cost. Let us summarize the major process; Laser Cutting, CNC Turret Punching, Press Brakes, and Traditional Stamping using a mold, pointing out the positives and negatives of the processes together.
Laser cutting is a simple process using a laser to cut a pattern out of a sheet metal sheet/plate. A sheet metal plate is put on a table and either the laser is programed to move or the table is programed to move to cut the shape required. This is the go-to for many products because it can be quickly and easily programed from a 2D drawing to cut any simple to very complex shapes.
Positives:
Negatives:
Summery, if you have a low quantity, very complex shape precision sheet metal fabricated parts, stainless steel material or thick material this is a very good option. However, laser cutting is easy to set up for the fabricator also so be aware they might force feed you this process if they are not equipped or specialized in other processes.
The CNC Turret Punch Press process that uses a turret that will quickly change tools to cut the desired shape while normally the table is programed to move to accept the punch tool. The tool rapidly goes up and down and nibble’s the cutout. Think of a 2” square hole, you would use a ½” cutter to nibble the cutout along the cut line until the cutout is complete.
Positives:
Negatives:
Summery, if you are looking at a routine production parts in Carbon Steel or Aluminum between the production quantities of 100-1000 or be able to do design changes on the fly, this is an excellent process to use.
When a part is cut utilizing a CNC punch or sheet metal laser cutter, when A bend is required, and sheet metal press brake is used. There are typically 4 types of press brakes, fully manually, CNC, robotic and automated to bend sheet metal to various bends profiles and designs.
These Press Brakes are set up to complete only one operation or bend at a time then the tooling is changed for the second operation. These are mainly used in prototype, very small production or for hobbyist.
CNC Sheet Metal Press Brakes take a 3D part file were the operator will input the required bends and bend angles in a sequence down the break utilizing preset separate tooling for each bend to complete a finished part. This increases the speed and accuracy of the production.
This simply a CNC sheet Metal Press Break replacing the human with a robot. The is another step to increase speed and accuracy of production however there is an increased cost in set up therefore and increase is quantity, MOQ, depending on the number and complexity of bend is required.
This Press Brake is a one system that moves the cut sheet metal part and then automatically changes the tooling and moves the part to the required position. These are used only for parts with and significant number of bends and with a high MOQ.
Traditional mold stamping is a process that requires a mold to be made to replicate the parts. Depending on the exact punch process you can punch martial of copper, nickel, aluminum, steel and stainless steel to great thicknesses. For small simple parts a single mold can be used to cut and bend the sheet metal without the need of a press brake. The larger and more complex the part becomes 2+ molds are used. To increase efficiency over multiple molds a “progressive die” mold can be used. This is a single mold were a long strip of material from a coil is feed into one end and as it goes through the mold from one end the material is punched in steps as it is pushed through the mold at the far end/exit the final step cuts the material off and a finished part is dropped off.
Positives:
Negatives:
Summery, if you have a high production quantity sheet metal fabrication with a long-life cycle that allows you to amortize the mold cost, this is the process of choice.
Other areas you should consider when at your design stage but not limited to are:
For sheet metal fabrication it all comes down to cost depending on your product and quantity. To understand more clearly think of a 2” x2” x2” open ended box out of 16 Gauge aluminum .A Laser cut and Brake bend would take less than 2 minutes to produce. On the other hand, a CNC Punch and Brake Bend would take less than 1 minute to produce. Last a standard punch press would take less than seconds to produce.
The last two items you must consider are a “Cradle to Grave” and a FULL-SERVICE COMPONENT CONTRACT MANUFACTURER.
FULL-SERVICE means the contract manufacturer can provide you with a finished part including machining, PEM/Fastener installation, Powder Coating, Plating (anodizing, Chromate, Alodine and so on) &silk screening/engraving, a “one stop shop” This eliminates having to resend out your part for a secondary process to a separate multiple vendors. The significant advantage to this is you now only have one source responsible for your quality and on time delivery needs.
“Cradle to Grave” means as your product matures, we will continually give you suggestions, (process changes, material changes, sub-assemblies) to reduce your cost giving you an improved sales advantage. Ionthis can do both!
For a DFM/Analysis of your Sheet Metal Fabricated component or assembly, feel free to contact Ionthis at engr@ionthis.com
