Leghart and Associates Inc.

Systems designed & built for:

Our team is available to assist you in all your control system needs.

Our satisfied customers

  • Crane Performance Siding
  • Midwest Industrial Supply, Inc.
  • the Timken Company
  • Tring Corporation
  • Corning
  • Gradall Industries, Inc.

Past Manufacturing Control Projects


The Holesaw Blade Forming System is designed to function as follows:
1.) Load flat blades, already cut to proper length, one blade at a time, into a rotary hearth furnace.
2.) Heat the blades to forging temperature.
3.) Remove the blades, one at a time, and place them into a water cooled die set.
4.) Form the blade into a circle.
5.) Remove the blade from the die set and transport it to the next stage of the manufacturing process.

The system is capable of loading, unloading, forming and transporting two blades simultaneously, using two separate loaders and two separate unloaders/formers. Both loaders and unloaders/formers work with a single furnace. When operating both loader/unloader/former groups simultaneously, the system is capable of producing two formed blades approximately every 10-12 seconds.

Overall control of the system is accomplished using an Automation Direct Productivity 3000 PLC. Motion control for the loaders and unloaders/formers is handled by four Emerson/Control Techniques servo systems, one for each axis.

Operator interaction with the system is provided by two Automation Direct 15" color, touch, C-More model human machine interfaces (HMI). Each HMI is primarily dedicated to one of the loader/unloader/former groups, while still providing overall system control and monitoring.

Two communication networks are incorporated to handle the information flow thru the system, Ethernet TCP/IP and RS-485.

The Ethernet network takes care of the following:
--Both HMI's
--Numatic remote I/O valve manifolds and I/O modules for both loaders and both unloaders/formers, four total.
--Development computer connection
--Plant network access

The RS-485 network handles communication with all four servo drives plus receives data input from four separate temperature monitoring devices.

A remote programming port on the main enclosure door allows access to both communication networks.


The machine being controlled is a 2-axis cutoff saw. One axis is used to position the material at the saw blade. The other axis moves the saw blade through the material to make the cut. The axes are independent of one another. Additionally, the saw spindle is run by a variable speed AC drive.

Overall system control is managed by an Automation Direct Productivity 3000 PLC. The PLC communicates via the Ethernet port with a C-More 12" operator interface, the program development computer and the company's plant network.

Both axes of motion utilize Automation Direct Sure Servo drive systems, communicating with the PLC over the RS485 network. The saw spindle uses an Automation Direct GS3 drive, also communicating with the PLC on the RS485 network. For all time critical signals, both servos and the GS3 make use of the discrete I/O available on the units.


The Vinyl Siding Lamination Line is designed to function as follows:
1.) Convey a pre-manufactured piece of foam thru a set of hot glue dispensing nozzles to apply glue to the foam.
2.) Simultaneously, convey a pre-manufactured piece of vinyl siding into position to be applied to the glued side of the foam.
3.) Apply the vinyl siding to the foam using a GE Fanuc multi-axis robot.
4.) Convey the assembled lamination thru a set of pinch rolls to complete the lamination process.
5.) Transport the assembled lamination to an automatic boxing station. The pieces are stacked into the boxing device using a second GE Fanuc multi-axis robot.
6.) Once the appropriate number of pieces is stacked in the boxing device, they are all pushed into a pre-assembled box at one time.
7.) The box is manually closed and sealed and then conveyed to an automatic palletizing station.
8.) At the palletizing station, a third GE Fanuc multi-axis robot loads the boxes on to a pallet in a pre-determined pattern.
9.) When the pallet is full, it is conveyed to an automatic banding station, banded and conveyed to a shipping station.

Overall control of the system is accomplished using an Allen-Bradley SLC-5/04 PLC. All conveyor motors and pinch roll motors are variable speed devices using ABB Model ACS550 variable speed drives.

Operator interaction with the system is provided by an Allen-Bradley PanelView human machine interface (HMI).

Two communication networks are incorporated to handle the information flow thru the system, DeviceNet and Allen-Bradley's DH+.

The DeviceNet network takes care of all the variable speed drives (14 in total) and the three GE Fanuc robots.

The DH+ network handles communication with the HMI and the Hot Glue System PLC.

The SLC-5/04 PLC actually provides control and command of all the variable speed drives along with receiving and transmitting data to and from the HMI. Other discrete I/O functions are managed as well.

Interaction between the PLC with the robots and the Hot Glue System consists of instructing each unit as to which particular model of siding is being processed, along with handshaking information and fault monitoring.