i need to rout wide grooves to accept router inserts i am doing this on my existing router table when i move the fence to widen groove the next cut is a bit deeper or shallower any ideas why this is happening.
-Larry
Rogers, MN
Portable Router Table
Our Expert
When making multiple passes with a straight bit it is typical to see slight variations in groove depth. There are a number of factors that contribute to this. For example, a router table top that is not flat, a router base that is not perfectly flat, deflection of the workpiece or slight unevenness in the stock being routed can all create minor variations in cutting depth. In fact, variations of as much as .003" to .004" in adjacent grooves are not unusual when hand routing. Greater precision would require a computer controlled router (CNC).
If you're experiencing more than .003" or .004" variation it could be caused by debris between the workpiece and the registration surface. Try using dust collection and sweeping the top of the router table between cuts.