Adjusting Cutter Height on the Router Table

Router Woodworking

The four 1/4" lifts accommodate an 1" of cutter height change. They are pretty much stuck on the shoulder bolt; keep it simple!

In my view, managing the depth of cut on the router table should be done with the fence when large diameter cutters are in play and with simple 1/4" lifts when the cutters are narrow and spindly. In either case the cutter need be set only once per session: at its end point.

In the example shown, the setup is for an open ended mortice with the cutter at full and final extension. A pass at full depth will break or burn out the cutter. A stack of 1/4" lifts surround the bit and lift the work so only a 1/4" of the cutter will be cutting/pass. The lifts are trapped on a shoulder bolt so no clamping is necessary. Pull one off after each pass to complete the cut.

Expect good cuttings as the cutter is always in the same place. Sometimes changing the cutter depth, (by whatever means), will change the axis of the cutter and produce "steps" or other anomalies along the profile. Given a good fence and well prepared material your cuttings should be laser crisp when routed on lifts.

That oak sample is on the way to its second cut; one lift is missing. For best results: mill squarely and use a fence that is square to the table top.

For large cutters the fence should be moved to change the depth east/west. The threaded hole in the out feed fence will accept the same shoulder bolt so the the lifts can be used on-edge. The lifts on-edge will effectively move the fence. Removing one after each pass will get you 1/4" closer to the cutter. In no time the cutter will be fully exposed and the cut completed. The lifts, now spacers, should be designed to handle your biggest cutter.

Big cutters are a safety hazard and require more than just casual attention. And although I hold the contrarian view, I would avise against using cutters greater than 2" in length or diameter in a simple 110 volt router table.