Figure 46. Rub collar set.
Above |
Figure 47. Rub collar mounted above cutter.
Between |
Figure 48. Rub collar mounted between two
cutters.
NOT RECOMMENDED |
Below |
Rub Collars
When shaping workpieces that have irregular shapes, rub collars are a necessity. There are two types of rub collars: solid and ball bearing. They are available in various diameters and can be purchased individually or as sets as shown in Figure 46. Some examples of when you would use a rub collar are raising arched or tombstone door panels, round table tops, or any other cut that needs to have its depth of cut limited. Refer to the set up examples below.
There are three set up positions for rub collars:
1.ABOVE THE CUTTER as shown in Figure 47.
This setup is the safest and produces the most consistent results. The only drawback is that the cut is on the underside of the workpiece, out of view of the operator. However, if the workpiece lifts off the table, you simply run it through a second time to finish the cut.
2.BETWEEN TWO CUTTERS as shown in Figure 48.
This setup has the advantage of making two profile cuts in a single pass. Although you have a rub collar beneath a cutter, this setup is safer than the previous setup. Any lifting of the workpiece will still cause the cutter to make an uneven cut. A second pass will correct the profile on the bottom edge, but the top profile will still have the gouge from lifting the workpiece into the cutter.
3.BELOW THE CUTTER as shown in Figure 49.
This setup allows the cut to be viewed by the operator; however, it is also the most dangerous. Any slight lifting of the workpiece will cause the cutter to make too deep of a cut. There is also an increased chance of kickback.
WE DO NOT RECOMMEND SHAPING WITH A RUB COLLAR BELOW THE CUTTER!