Lock Miter Router Setup

Set the approximate fence depth by visually.

Lock miter router setup.

One is for smaller router bits cutting 3 8 to 3 4 thick stock the other is for the larger bits cutting 5 8 to 1 1 8 thick stock. You need to get both the fence position and the bit height exactly right in order for this joint to work. In an effort to not completely derail that thread i thought it would make sense to have a dedicated thread to discuss tips and tricks to setting up a lock miter joint on the router table. Simple steps for airtight joints.

There are two sizes of the lock miter master jig. In woodworking circles the lock miter is often referred to as a trick bit by a feat of geometric genius the bit creates both halves of a mitered corner complete with interlocking tongues and grooves with a single router table setup. With the lock miter master jig you can set up a lock miter bit in no time at all. A lock miter bit is one of the most challenging router bits to set up.

Set the initial router bit height by using a piece of your stock as a reference. That is the fence would never be set that far back. A lock miter router bit cuts a 45 degree miter with a tongue and groove. Align the midpoint of the lock miter cut with the centerline of the workpiece.

45 lock miter router bit instructions set bit height and fence depth 1. When correctly cut the parts go together at a perfect 90 degree angle and the interlocking tongues and grooves make for lots of mechanical strength and glue surface area. On the thread mentioned above there were many good suggestions for setting up the lock miter. Router bit item 55 502.

First a diagram the numbers shown are for the infinity lock miter jr. Your goal is to have a and b equal to each other.