If you missed part one of our series on roll forming automation, you can click here to read it.

Technology to the rescue: Automation

Technology is becoming the answer in many industries, particularly the automation process in manufacturing. Today we are all in a global economy and companies are in competition with not only domestic suppliers but those abroad. Companies are looking to technology to create repeatable and efficient processes to compete. Automation technology is the answer.

Replacing the expert will never be completely accomplished, but creating tools for the novice will help reduce the stress. The feel is one big obstacle to overcome. When a person uses feeler gauges on the roll tooling they are actually feeling the pressure of interference with the feeler gauge between the flanges of the roll tooling. This is a process that has been done for years in the roll forming industry and takes years of experience to understand the proper interference. If the machine is older and has wear, it feels different, than a new machine.

The adjustment of the roll former is simple. The bearing block has a threaded rod attached to it and the block is moved up or down to create the proper distance or gap between the top and bottom form rolls. The bearing blocks set the rolls in the desired vertical gap, which creates pressure on the material and bends the material to the desired shape. The tooling not only bends the material but also pulls the material through the point of pressure. This forming progression can vary from being very simple, with a few stations, to complex, with a lot of stations.

The process seems simple, but as time goes on the machine begins to wear and the interference of the threads begin to decrease creating slop. The result of this is when the roll tooling is set without material; thus, the top roll is pulled down by gravity. Once the material enters the roll the slop is taken up in the threads and the feeler setting is no longer valid. The end result is the tooling is set with improper roll gaps that often require the expert to reset the pass to the proper settings. This action is where the feel comes in. If the threaded rod has increased friction or decreased friction then the expert has to determine if it is the roll former or the pressure on the material.

Teaching the feel is very difficult. To overcome this, the application of automation technology has presented the industry with options. One option is to use the techniques that have been used in the tube and pipe industry for years.  Anti-backlash screw jacks are used that have minimal backlash. This tolerance is typically better than many or all the experts feel in the industry. Taking it a step further and connecting the inboard and outboard adjustment the pass becomes a single point adjustment (SPA). The advantage of the SPA removes the feel and keeps the roll stand parallel, which reduces twist and other undesirable results.  A traditional SPA also has a digital readout, which provides confirmation of position, which can be recorded, for future setup reference.

The automation advancement for the SPA is to add a servo motor. This allows the novice to adjust the roll former from a control panel. The adjustment is the same as using the feeler gauges, but instead of using a subjective sense of pressure, the measurement is the vertical distance of the top and bottom roll shaft positions, which can be programmed to match the engineer's precise tooling dimensions that were developed in CAD. This change in the measuring method allows for a distance that can be documented and recorded, and programmed, for insured repeatability. The recording is done through the control with the positional feedback.

By adding servo motor adjustment with positional feedback, the roll tooling changeover process now looks like this:

• Roll Former Operator used the HMI Operator station to put the roll tooling in the load position
  • All the shafts are adjusted to the top vertical distance to unload the tooling. The shafts are moved in the vertical direction by motors instead of a human.
• Roll tooling is changed to the next product
• The operator or set up personal calls up the program for the tooling at the Operator Console HMI.
  • Roll tooling is set to the desired setting
• The material is fed into the roll former
  • If any of the passes go out of tolerance range the passes will adjust themselves back to the desired setting.

With process above one can see that technology is filling the gaps and eliminating Black Art. The demand for the expert with the feel is being replaced with actual real-time and measurable data. Metrics and history of the roll tooling can be tracked through the machine controller for future reference.

Single Point Adjustment (SPA) technology eliminates the need for the feel. Keeping the roll shafts parallel through the adjustments and the production run has many benefits. The novice can adjust the pass individually and risk of offsetting the tooling is eliminated. This reduces product distortion and tooling breakage. The SPA fitted with a digital readout and the HMI display the vertical position allowing the adjustment movement to be displayed.

The automation and positional feedback of the roll shaft position is very useful. All adjustments to the roll form line are documented and saved in the PLC. This allows for historical data on the roll former as well as the roll tooling set being utilized. Since the adjustments are automatically recorded by the controller, the operator error of not documenting the change is eliminated.

The use of the SPA and the servo motors create repeatability. The tooling is positioned to the same location on each setup. This eliminates the different feel that can vary from one operator to the next. The positional feedback ensures that the distance between the top and bottom shafts are within the mechanical tolerance of the SPA’s.  

This roll former also adds the benefits of historical and real-time data. The information gathered from the roll form line is recorded and documented for future use. When an adjustment is made by the operator the operator enters their code and the adjustment is recorded. With the positional feedback, if the roll pass drifts out of adjustment, the smart feature is activated and the servo motor corrects the pass. This movement is also documented. This type of information gathered from the roll forming process will allow process engineers to have data to make future decisions on process issues.

The manufacturing industry continues to demands skilled workers of which there is still a shortage. To overcome this gap, the industry has a mechanical, electrical, and documented automation solution. The elimination of black art and feel allows for a monitored process which is not being done in the roll form industry. Automation is replacing the wrench and feeler gauges with motors and controls. The days of the roll former being a mystery are over. Technology and measuring devices are putting the light on the process and the result is an efficient, repeatable, and monitored roll form process. This increases the benefits of the roll forming industry.