The machine in Figure 1 can cut either cut one long piece of extrusion into three equal length parts or cut one end of an extrusion a precise length from a molded detail on the other end of the machine. The machine is equipped with a fan, a work light, and an air hose.
The part to be made is selected by a switch on the control panel. If the part with the molded end is being trimmed, only one of the four cylinders that carry the cutting knives advances. For the other part all four knives advance to trim both ends and make two cuts to divide the remaining extrusion into three equal parts.
Figure 2 shows the one end of the loading tray, which rolls on linear bearings in the forward position. The extrusion is loaded onto the tray, the part of the tray with handles is folded down to capture the extrusion and then the tray is rolled into the machine. When the tray is fully inserted, sensors initiate the cycle. First the tray is locked in place until the cycle is complete. Then the appropriate knives advance to make the selected cut. Only then is the tray unlocked to allow the operator to remove the tray from the machine and remove the trimmed parts.
The sequence of operations is controlled by a PLC controller located in the control box shown in Figure 3. The controller first checks to see if the raw extrusions are positioned properly. Then when the loading tray is properly positioned, the PLC advances the locking pin to secure the tray in place. Then it directs the rest of the operations, checking to be sure that the knives complete the required cuts before it unlocks the tray and allows the finished parts to be removed