Custom Roll Forming

Description

Custom roll formers manufacture roll formed parts under contract for others. The custom roll former normally owns a number of roll forming machines. These manufacturers will provide bids for roll tooling and cutoff dies along with the material and labor to produce a certain number of parts. Customers typically come from the appliance, furniture, and automotive industries. Normally, contracts call for a large number of pieces in a short period of time.

Because of tolerance constraints, most roll forming machines in the custom roll forming industry are controlled by gauge bars.

Industry Concerns

A custom roll formers primary concerns are part quality and productivity. Customers demand tight tolerances both in length and shape of the part. Custom roll forming is a highly competitive business that demands high production rates with minimum material scrap and few production delays.

Since most custom roll form jobs are of relatively short duration, the machines must be capable of quick changeover.

Common Problems

The most common problem facing a custom roll former is the tradeoff between quality and productivity on machines whose length is controlled by gauge bars. The gauge bar insures accurate lengths because the part is trapped between the die and the gauge bar. However, the end of the part must collide the gauge bar for each cut. This collision limits the speed of the line if damage to the end of the part is to be avoided.

A second problem with a gauge bar is the excessive maintenance required on the mechanical components of the machine. When a cut is made, the material is being compressed. This leads to increased die wear and added potential for jam ups. Also, gauge bars may often get out of adjustment and can require frequent checking.

How AMS Can Help

The ideal product for the custom roll forming industry is the AMS Controls Tru-Trac Closed Loop Die Accelerator System. Tru-Trac consists of a linear actuator, servo motor, and electronic controller. The gauge bar is removed and the actuator is attached between the machine base and the moving die.

With Tru-Trac, the material is measured electronically. When a cut is to be made, the controller accelerates the die to material speed and maintains that speed while the press is cycled. The die is then returned to its home position to await the next cut.

Since the die is moving at the same speed as the material, the cut is made as if the die and material were standing still for a very clean cut. Since the gauge bar is removed, the leading edge of the material is free, and the part is not being compressed when the cut is made. The result is no damage to the end of the part and no distortion of the roll formed shape.

Since the collision between the material and the gauge bar has been eliminated, the line speed can be greatly increased. Double or triple line speed is common when Tru-Trac is added.