As sections become more complex and the cost of tooling continues to escalate, it is more critical than ever for engineers to make sure the designs they come up with for a product work as expected prior to a major investment in tooling. Even designs created with the best computer programs, FEA’s, and computer models are not always right. With an investment of tens of thousands of dollars in tooling needed to make some of the sections, companies need to be certain all aspects of design, fit, form, and function work for that product.
As a response, ARF has developed some of the most complex and cost efficient prototyping processes to ensure the product will work as designed prior to the need to invest in finished tooling. Through the use of techniques such as soft tooling, press breaking, and turret punching, clients can know exactly what their part will perform like once it’s in a full run by working with ARF to produce “to print” samples of their product. These prototypes can be produced in a much shorter lead time and at a drastically reduced cost when compared to creating expensive tooling just to prove a concept will be effective.
The Need for Prototyping
Many times the parts designed do not meet the manufacturing expectations of clients due to unforeseen issues that were not discovered in the many hours of computer simulation or “stack up” tolerance studies performed. With the economy so tight and margins so slim, clients cannot afford to pay twice for the same tooling, once for the initial tools and then again to modify the tools when they do not make the shape as planned. The time to rework tooling to achieve the desired part may extend from days to weeks depending on the issues, often causing release delays and cost overruns.
For many companies, decreases in project lead times and product roll out times are adding to the complication of accurate prototyping. Although FEA’s can be used to determine the problem areas of forming before the first roll is cut, an actual sample may be the only way to see if the design chosen will actually work. Actual samples can help guarantee the tooling outcome because of what is learned when the samples are made.
Another reason actual samples may be necessary is that many times roll formed samples have other operations that need to be performed on them and other machines that need to be built to complete the final parts. The lead times for finished parts may be unacceptable when additional time is required for jigs or fixtures to be built. In this case, an actual sample made to print is essential to keep the project lead times in the required time frame.
An Example of Prototyping Success
As an example of our prototyping capabilities, ARF recently had a new client send us a design for a complex section they wanted us to produce. The part was previously produced as an aluminum extrusion and they were interested in turning the part into a steel roll formed shape for cost reasons. They wanted to go roll forming but they were not sure it would work as well as the aluminum extrusion. They wanted to give us an order for tooling at a cost of $65,000 (for rolls, pre-punch die, straightner, and cutoff die) but they were hesitant that their design would not yield the results they expected.
The drawing called for a light gauge section made from .035” thick G-90 pre hot dipped galvanized steel. The part had three fairly straightforward 90 degree bends and two trickier complex radius bends. The part also had numerous holes in it along with notches on the end where the radius bends were occurring. The drawing allowed for virtually no end flair or deformation on the cut.
To prototype this part, ARF suggested making “to print” samples of this complex shape to test the product prior to investing in finished tooling. Our engineers and tool making partners put their heads together and decided that the best way to make the samples was with a combination of “Soft Roll Formed Tools” for initial forming and our turret and press brakes for the final forming.
The other benefit of “Soft Roll Formed Tooling” is that softer steel can be used for the rolls. Unlike normal tool steel, this significantly less expensive softer steel is not heat-treated and hardened but instead cut on a lathe and is ready to be put on the mill without any other work being done. Unlike hardened tooling, the lead time can be as short as 1 to 3 weeks as opposed to 10 to 12 weeks for normal hardened tools made from D2 type steel. The soft rolls can be recycled after the proofing session once the part is prototyped to the satisfaction of the client.
Producing the Prototype
Our engineers determined that the roll formed portion of the part needed 8 roll formed passes to get to spec. Turret punching could be used to create the required holes and end notches and press braking for the remaining three 90 degree bends. Based on this prototyping process, the client placed the order for the soft tooling and the rolls were designed and made in just three weeks.
In the meantime, ARF ordered the steel sheets for the galvanized material and brought it in to be nibbled out of the sheet on the turret. This was done and the sheets were nibbled and punched in the turret with the appropriate holes and end slots prior to the arrival of the soft tooling. The punched strips were then welded together so that they would go through the soft tooling as if they were in coil form, ensuring a continuous flow of material through the rolls and simulating the normal roll forming process.
After the parts were rolled to print for both shape and tolerance they were forwarded to the press brake for the final forming of the 90 degree bends. Our quality control department tested the parts to make sure that they were made to the specifications of the print and were ready for delivery to the customer.
ARF was able to supply the customer with 20 samples of each of 6 different length parts to test and try out in their final application. The customer’s test revealed that the roll formed part worked as well as the aluminum extrusion at a much lower cost and the customer placed a production order for the final tooling. Next year’s volume for this part is expected to exceed 750,000 feet of steel.
In the end, this sample run cost the customer less than $8,000 total compared to the $65,000 investment required to build the final tooling before the process was proven as a suitable replacement for the existing extrusion process. This is in addition to the significant per piece cost savings that accompany the switch from extrusion to roll formed parts.
Make Roll Form Prototyping Work for Your Company
If you have ever thought of looking at roll forming as an alternative to another process, let us know. Utilizing processes like soft tooling and our engineering best practices we may be able to provide you with the “to print” samples you need to make an accurate and informed decision!
Call us at 440-352-0753 or visit www.arfpcorp.com/capabilities-and-services/overview to learn more about how we can help you test your products and save money through roll forming.