Climb-Cut Routing, What is Climb-Cutting

Climb-Cut Routing

WARNING! Climb-cutting with a router increases the risk of serious injury. Read, understand, and follow all of the warning messages below:

►The router bit can grab the workpiece at any time, resulting in a loss of control.

►Never attempt climb-cutting with large diameter bits. The larger the bit, the more likely it will grab the workpiece.

►Never, under any circumstances, attempt to climb-cut with a table-mounted router. The workpiece will catch and will be propelled off the table.

►Never climb-cut around an interior cutout in a workpiece. The bit can easily catch in the corners.

►Friction mats alone are not sufficient for securing a workpiece. The workpiece must be fully secured in place with clamping devices.

For the reasons stated on this page, Festool recommends against the practice of climb-cutting with a router, especially for inexperienced users.

What is Climb-Cutting

Climb-cutting is feeding the router in the same direction as the rotation of the bit. The primary cut is made as the tip of the cutter enters the edge of the workpiece (as shown below) instead of exiting the edge of the workpiece. The result is that the wood fibers are being compressed and sheared during the cut instead of being pulled apart. This compression during the cut results in less tearout of the wood fibers, except when cutting end-grain.

When climb-cutting end-grain, the fibers are compressed longitudinally before being cut, and this will result in an uneven surface and damaged fibers. For best results, do not climb-cut end-grain. Carrying this concept a step further, if you are routing a non- rectangular workpiece, such as a circle, then best results will be achieved with a combination of climb- cutting and push-cutting. In the example circle shown to the right, note that the transitions between climb- cutting and push-cutting do not occur at 45° positions as you might have expected. This is because climb- cutting has a greater benefit in the end-grain-to-edge- grain transition, and push-cutting has the greater benefit in the edge-grain-to-end-grain transition.

Aside from the increased risk for loss of control, a drawback to climb-cutting is that the router bit will tend to push the router away from the edge of the

workpiece. This can have two consequences regarding the quality of the cut. First, the router will not cut as deeply as expected. Secondly, the routed profile will tend to have a scalloped surface, called chatter (see page 17). To overcome these conditions, it is typically necessary to make a second, clean-up pass across the cut. This second pass can be either in the climb-cut or push-cut direction.

Notes and Tips

►As with any power tool, respect the danger, but do not operate the tool if you are afraid of the operation. If you are afraid of the tool or the procedure, your reactions will be controlled by fear, not rational thought, and your reaction may actually create a greater danger.

►Do not rely on your reaction-time to control the router feed rate, use friction. By holding your forearm (while grasping the router handle) firmly to the workpiece you use friction to assist in keeping the router under control (see the image and discussion on page 17).

►You will have greater control of the router when you route away from your body (with the router pulling against you, versus pushing into you) with your arms outstretched.

►When routing a multi-sided workpiece, first push-cut the end-grain, and then climb-cut the edge-grain. The end- grain tearout will be removed by the edge-grain profile.

►Make multiple shallow passes when feasible.

18	OF 2200 EB Router