Hand-held Router Accuracy

Routers are not perfectly centered from the factory, and require tuning. You'll notice it on fine-tolerance work such as dovetail joinery.October 4, 2011

I have an 890 Porter Cable router and am using a Leigh D4 jig. The issue I have is the guide collar on the router. I can never seem to get it perfectly centered. I have tried different collars with the same results. I have to hold the router exactly in the same position in and out of the fingers in order to avoid gaps in the joint. I suppose I could rout the joint with the router one way, then turn it 180 degrees and go through the fingers again to be sure the cut is centered, but I shouldn’t have to, should I? If the router turns even a little, gaps appear between the tails and pins.

Rather than switching bits back and forth, can the joints be cut using a setup with two routers and still get a good fit? I don’t have that second router, but would buy one if that would work. Is Porter Cable the way to go?

Forum Responses
(Solid Wood Machining Forum)
From contributor D:
Half the routers we've bought are out of center. There is play in the face plate of the base, the retaining ring and collar, and the base itself as it's tightened around the motor. It's a time consuming pain loosening, tightening, and banging things around to get a collar centered, so when one was set up for a certain task, like routing hinge mortises, everything was reefed down extra tight and we left it alone. My guess is overtightening the aluminum base warps it as well, but I've seen plastic bases out of whack too.

From contributor S:
Contributor D is exactly right. The plastic base has to be centered to the bit. One other thing - do not sand any parts until you have dovetailed them. Before you assemble is when you sand. When you sand the inner faces, stay 1/2"-1" away from dovetails. Also make sure the template sits of the jig sits flat on your stock. Remember anything that does not line up or is 1/128" off doubles with dovetails. Try and designate your router only for drawers and do not bump it or bang it. These are the two most well cared for items in my shop.

From contributor M:
As an old door hanger, I always preferred the Bosch routers, as the bushing mounts in the metal base and not on the plastic base plate. I was never a fan of the PC bushing setup and that stupid screw-on ring. Basically I am saying, try a different router!