Photo Coming Soon
FEEDTHROUGH CENTERING JIG
Larick’s centering jig allows arching capability on the Model 390 Shaper. Templates for arched rails or panels are installed in the centering jig which is placed on top of the parts, then fed through the machine. The machine’s hold down pressure secures the jig and rails or panels to the conveyor. The spindle moves back and forward with its position controlled by a bearing on the spindle which follows the template as they move through the machine, pushing the spindle back and allowing it to move forward.
The jig’s thickness is one inch above the part which includes a ¾” thick template. Side guides move to center the part under the jig with a knob. For rails, fixtures are installed/removed with 2 screws each. These fixtures control the finished width of the arched rail.
Three template styles are available: Traditional Arched Panels with a 1.5 inch arch height, Eyebrow Arches with a maximum arch height of 1.2 inches, and a Flat Top Arch with a 1.5 inch arch height. Each template set includes 24 templates, 12 each for rails and panels.
To use the jig to create an arched rail, the ‘stop’ fixtures and the desired template are installed in the jig. A rail is laid on the machine’s top, and the jig placed on top of the rail. Turning the knob on the jig moves the side guides in to center the part. The jig is then pushed against the 390’s fence which forces the rail against stops in the jig. While maintaining contact with the fence and pressure on the knob to keep the part centered, the assembly is fed into the machine. After half of the jig is under the hold down wheels, the operator may release the knob and is now ‘hands off’ until the machining is complete. The operator can then place another rail on the infeed table, pick up the jig as it exits the hold down section, drop the part out of the jig, then place the jig over the next part and feed it through to be machined.
To machine an arched panel, the stop fixtures are removed, the appropriate panel template installed, and the feed process is similar to that of a rail. As the jig is placed on top of a panel, allow the panel to extend beyond the jig, then, using the centering knob, turn it to center the panel. Keeping centering pressure, place the panel against the fence and slide the jig over the panel until the template also contacts the fence, then feed the assembly into the machine, maintaining pressure with the centering knob until about half of the jig is under the hold down wheels before releasing the jig.
Larick recommends using a straight hogging cutter to create the arches on both panels and rails. For rails, on the 390, tooling is stacked. Normally, the hogging cutter is on the bottom with a rub bearing with the same diameter above it. A rail cutter is next with a bearing about 1/16 inch smaller than its minor diameter above. This method of first hogging out the rail, then profiling gives a better finish because the profile cutter is only removing 1/32″ of material and the profile so does not burn the part. The 390 machine also has the capability to have its feed rate to be controlled by the shaper’s load, and to have different rotation directions in the raised (hogging) position and lowered (profiling) position. This allows hogging to be done using a climb cut (CW rotation) which does not split the rails because the wood is being compressed as it’s cut. Profiling can be done with either rotation. The 390 will automatically change its rotation direction when the spindle is raised or lowered.