I was wondering if all you great minds out there could share your experience and knowledge in  sheet metal progressive manufacturing design. I have a little experience in this area and  it is clear to me that to facilate good design one must have extensive knowledge and experience.

I know that developing the proper sequence to create a finished part from a flat strip can be the most critical step of the design process and is very important to cost effective manufacturing. In my view it can also be the most design and engineering intensive and requires knowledge of many disciplines including material shearing, material forming, material springback, die design, die materials, die build, manufacturing set-up, manufacturing operation, product quality control, secondary process operation and process capability.

A sheet metal progressive die is used to manufacture a flat strip of sheet metal into a completed part. This is done incrementally, or progressively, by a series of manufacturing steps or tools that cut, form, coin or punch the material into the desired geometry.

The steps or tools used in the manufacturing operations generally are different for every part. The die is mounted in a drop hammer or press that moves the die up and down. The press is often configured to feed the sheet metal part through the die, progressing it from one station to the next with each stroke.

The following are some consideration that I am aware of:

• Avoid sharp corners
• Features should be as large as possible as small features add significant cost and tend to initiate manufacturing induced stress cracks.
• Largest bend radius possible. 1.5 to 2 times the material thickness.
• Do not design in dramatic cylindrical transitions (small cylinder to very large cylinder). Try to use transition that are at least 45 deg. between cylindrical features.
• Material selection is a critical consideration.  I know that aluminum tends to be more formable, however stainless steel, when thin, works well for progressive die manufacturing.

Well, this is all I can think of for now.