CUSTOM SYSTEMS ::: Mill Turn

This is a cell designed to make various turned and milled parts within a specific size range. The parts may be all the same, or all different, depending on the orders. The cell contains a Vertical Turning Center (VTC), a Vertical Milling Center (VMC), a pallet robot, a fixturing station, and pallet storage. The parts in this cell are generally round, but can be any shape if desired.

To begin the process, the operator receives a pallet on the fixturing station with specific on-screen instructions of what material to load and how to fixture the part. Any special checks or procedures can be included in the instructions, and they are supplied and maintained by the customer for quality control. The pallets here are modified manual chucks to make fixturing quick and easy. The station has the same clamps as the machine beds, and is mounted on a precision rotating bearing for quick indication and easy access. The operator can fixture non-stop during each shift, eliminating the down time normally associated with machining.

Once the part is fixtured to the pallet and checked with either a CMM arm or indicator for runout, the robot puts the pallet back into storage while bringing the operator another pallet with the second arm. The operator, like the machines, never has to wait long for another pallet. The pallet station and the machine beds have high precision pallet clamps that accurately locate the pallet to within 0.0001”. Once the part is fixtured to the pallet and checked on the fixturing station, it will be located accurately until the part is removed.

Once the VTC is free, the robot retrieves the pallet and part, and loads it onto the table using high precision pallet clamps. The part program is automatically loaded, and the machine begins the cycle once the robot is clear. The part is turned and retrieved once again by the robot to be sent back into storage. If the part needs to be turned over or removed, it will remain in storage until the operator is ready. If the part needs a milling process, it will be sent to the VMC. The number of pallets is set by the customer, and reflects their desire to operate one shift per day, and cut non-stop.

Each machine has a tool magazine and automatic tool changer. The cell controller tracks tool life and can use tool probes to detect broken or worn tools. If nobody is available to change broken tools at 2am, the robot can be designed to incorporate tool pallets to automatically change out tools as needed. Giving the operator every broken or worn tool in a group instead of dealing with each one as it happens.

All parts and the cell status are tracked on the cell controller by the operator, as well as management and production through the customer’s network. Any computer on or off the network can view the progress of any part or the status of any machine with a simple logon. The order in which the parts are loaded and cut is determined by the priority of each order, and is automatically controlled by the system. Priority can be adjusted on the fly, and orders can be inserted and pushed through quickly on demand.

As capacity increases, the cell can easily increase the number of machines, pallets, and fixturing stations as needed. The robot can be modified to operate with machines on both sides of the track for more capacity, or reduced to only one arm to save money at the expense of machine downtime. Nearly any type of pallet can be used as long as the size and capacity are known during the design process. Many machine types can be used, and even some existing machines can be integrated into the cell if a custom machine is not desired. The robot can be removed from the system, and each machine is a standard machine capable of normal operation.

Once the parts are done, they can be measured with a CMM directly on the fixturing station if required. Exact directions are again displayed on screen and measurements are automatically stored and checked to verify part geometry. Instead of transporting the part around the shop for different operations and eventually to a CMM for inspection, the part is totally finished in a short period of time without ever leaving the system. The operator can average only a few minutes of work per part, though the machines may spend hours machining them. The system also gives feedback on the efficiency of the system and the production. Systems similar to this have consistently proven to pay for themselves quickly with their low operating costs and high production capabilities.