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I have three of the DeWalt 618 routers, two are 3 base kits and one is a two base kit, plus a bunch of other routers of several brands. I use the fixed base of the two base kit one of my router tables because I like how it adjusts with the ring adjustment of the fixed base router. Actually my other router table also has a fixed base router in it right now too. They are quite accurate and easy to set the correct bit depth. I much prefer a fixed base router in a router table, and I don't really understand why you think that a plunge base would work better. To me it doesn't, when used in a router table.
For a 45 degree bevel, I would use a 45 degree bit with a bearing, in the fixed base router, mounted in the router table, and I would adjust the height of the bit so that It produces the width of 45 degree bevel cut that I was looking for. Raise the bit for a wider bevel, lower the bit for a narrower bevel, until you raise the bit so high that the bearing will no longer ride against the flat edge of the wood that you are cutting, or until the widest part of the bit is no longer large enough to satisfy your needs. Once you have adjusted the router to the desired height, it's easy to lock the router at this point and make your cut feeding the board clockwise around the bit. I believe you may be over thinking this.
Without a router table, but still using the fixed base with the router, you would again adjust the router until the bit produced the correct width chamfer, lock the router base and then feed the router along your board counter clockwise to cut the chamfer with the bearing on the bit riding against the edge of the wood.. A plunge base router could also be used, hand held, with the same bit, if you set the plunge depth to stop at the depth needed to cut the chamfer desired. Once plunged to this depth you can move the router counter clockwise around the board in the same way to cut the chamfer.
A plunge base router could be used in the router table, but I much prefer the fixed base for the router table and plunge base for free hand routing. It;s just easier to dial the desired cut in the router table for me.
Central North Carolina
Last edited by CharleyL; 08-28-2017 at 04:31 PM.