As Davi approaches 60 years, the world’s largest manufacturer of plate rollers and angle rollers – and the first all-electric plate roller – continues to lead in innovation and by example. FAB Shop Magazine recently spoke with Marco Chiarabelli, North American sales and operations leader, to discover some of the keys to Davi’s success and how it has made an imprint on the industry.
But, first a few statistics. Based in Italy, Davi builds about 300 machines per year with 95 percent being exported, of which North America accounts for about 30 percent. With more than 10,000 machines installed worldwide, Davi has offices in Dallas and Shanghai and a network of more than 100 dealers.
Davi’s plate rolling machines serve a wide range of markets that incorporate a variety of materials. Customers include those in industries such as wind energy, nuclear power, space, aircraft and shipbuilding. Wind energy and nuclear, in particular, present the most challenging applications with the biggest, thickest plate.
Chiarabelli notes the company’s private ownership, strong financial standing and employee satisfaction as key factors for success. Innovative technologies that make plate rolling work for today are additional factors.
FSM: Is plate rolling a challenging process? What are some of the difficulties?
Chiarabelli: Although the rolling principle isn’t that difficult to understand, rolling plate is harder than it looks. It’s more than just bending the material; it involves understanding the different material properties and machine capabilities. Thicker plate can be even more challenging, especially if the operator is inexperienced. For instance, if a plate is overbent, it’s hard to undo that or fix it. Additionally, plate wrinkling, surface damage or deformation can occur if uneven pressure or excessive bending force is applied or if the plate radius is miscalculated during rolling.
Therefore, throughout a typical rolling process, the operator checks the radius on the “can” (cylinder) they just rolled against a template that is the specific radius they need to achieve. Often, it’s necessary to do the same operation multiple times, which means they have to manually check the radius, go back to the CNC, make the adjustment, push the plate a little further and repeat this procedure multiple times until they reach the desired radius. This back-and-forth procedure happens several times, even with the same piece of plate.
Making a mistake in this process can be very costly. One plate can cost $1,000 or more. For an inexperienced operator, the process takes even longer and mistakes are more likely. And, as everyone knows, companies are increasingly dealing with inexperienced operators as experienced ones retire and so on.
How has Davi tried to address the skilled worker shortage?
We have tackled the shortage of experienced operators by providing products that help our customers – and this new generation – be more successful.
One approach from Davi has been to develop smart solutions to help new operators become familiar and, from a certain standpoint, be more successful with the machine. These smart solutions produce results that typically require years of experience. Davi brought in AI through a series of devices that we developed – and are still developing – to help the operator have a more controlled or monitored process.
Our laser radius measuring system combines AI with a specific algorithm, which allows the machine to read or measure the radius of the can throughout the rolling process. By removing the need for manual templates, the system speeds up the process and reduces dependency on skilled operators.
And, on top of that, once a measurement is taken, the system sends the data to the machine’s CNC to automatically self-correct in real time. The machines can now self-learn using data and statistics. The more the machine is used and the more it learns, the more it can provide the right combination of parameters. Up to three or four years ago, this was a dream for many of our customers. But now it’s a reality.
For shops using machines without CNC controls, the iRadius system provides a digital readout of measurements, enabling operators to manually adjust the machine settings as needed. The system is fully retrofittable to existing machines, making it useful for extremely large parts.
How does the AI system adjust for materials with defects?
Unlike traditional single-point laser systems, the Davi laser measuring system utilizes a “laser blade” that scans a wider rounded area, taking thousands of points along the curved surface of the radius at one time.
This means it can read material characteristics, allowing it to detect and compensate for mill scale and other imperfections. Mill scale is basically on every single plate. When reading a specific radius, if the reading is based on only a few points and one of those points is affected by mill scale, it can completely affect the results of a reading. This can lead to overbending or requiring more passes to get the final result.
Instead, with our system, the laser blade reads the points that are statistically off where mill scale is present. The machine understands that something is wrong and automatically removes these few points from the reading, allowing the machine to give the correct reading to the operator.
We’re also developing software to detect cutouts or other imperfections in the plate. The machine will be capable of understanding how to account for that hole, etc. While our software development specifics are proprietary, I can say that all Davi software is designed with a single-piece-batch production strategy in mind. For our customers, the benefit is a machine with high flexibility and capable of managing small batches of identical pieces.
What other types of automation can improve the plate rolling process?
In addition to automation, such as loading and unloading materials to reduce cycle times and be able to process more parts, controlling the parts throughout the process is important.
This is where supports to guide the material during the rolling process factor in, especially for wide, thin materials. This support can be vertical, overhead or lateral. The hard part is the communication between the table, overhead support, lateral support and ejector in such a way that the rolling cycle is completely automated.
Another aspect we’re proud of is our machines are often installed into production lines where the rolling is just one portion of the process. In those instances, we work with the OEMs and integrators to deliver a completely integrated system to the end user.
Can you briefly discuss the benefits of an all-electric plate roller over a hydraulic one?
There are several advantages of all-electric machines over hydraulic ones, including higher accuracy and speed because an electric motor is more accurate than hydraulic.
Also, higher productivity results thanks to the nature of the electric machine, which can have simultaneous movements, making it ideal for automation. Roller movement in hydraulic machines is generally limited to one or two axes due to the finite supply of hydraulic fluid and the mechanics of fluid flow within their systems.
Another benefit of an electric machine is lower power consumption. The electric machine only uses power when the machine is actually rolling. A hydraulic machine is always on to keep the hydraulic oil flowing. All in all, electric machines are much easier to maintain, require fewer parts and no oil system, and have a smaller footprint because no hydraulic cabinet is required.
Currently, electric plate rollers are limited in terms of application and capacity, so they aren’t for every industry, such as oil and gas and wind energy. Industries such as aerospace though already recognize the advantages, and as the machines continue to expand in size and capabilities, more industries will be able to take advantage of them.
What other characteristics make Davi unique in the industry?
What makes Davi different is our approach to installation and integration and our North American team that provides quick response and support. We have a large technical support team here in North America, which translates into quicker turnarounds for customers across the United States and Canada. Some customers even have a dedicated service tech in their facility.
Davi also offers standalone and customized machines. We partner with customers before the machine is chosen to understand which is the right one for them and provide support for the customer after the machine is purchased.
