In terms of roll forming accuracy and roll movement, fabricators actually have more control than they may think — if they have the right machinery and equipment to accomplish the precision standards they need to reach. When feeding coil, choosing the right servo feeder can be the key to achieving your roll repeatability goals. Here are some things to consider when you want to choose a more accurate servo feeder setup for your roll forming operation.
How do Servo Feeders Improve Accuracy?
In many cases, fabricators commonly use a die to form a pilot hole reference, then opening and closing the servo feeder so that you can let the strip move with respect to the additional pilot hole. That's typically done via an encoder on the wheels or the rolls themselves to denote the location. This ensures repeatability by accommodating from the hole to hole location. This pilot hole style likely the most accurate, given that the system has the correct accommodations in the die itself.
However, there are other options utilizing the servo feeder that can achieve accuracy close to that of the pilot hole. One option involves putting the encoder on the material, looking at the revolutions of the servo feeder, and comparing the two to see if there’s slip. By looking at the feedback from the servo feeder, we can see an error code or know that something’s not right, but we can still follow what the encoder on the material is doing.
Another method for improving accuracy would be what we call batching and gagging. It’s not necessarily hole to hole, but it would be used in an application where there are patterns or a groupings of movements that have to follow. Some servo feeders have a feature called programmable pattern control where you are capable of this kind of non-consistent hole spacing. An advantage with the servo feed is the flexibility to provide that type of capability that is not the case with the more mechanical type of feeders. Servos with this feature would be able to reference accuracy at these variable patterns.