What HP router are others using to cut half blind dovetails? I currently use a Dewalt 610 1 1/2 HP router with a PC Omni jig and we break a bit on almost every job. I have tried 6 different brands of bits with the same results. We use 5/8" poplar for drawer parts and we do get some chatter. We like the Dewalt 610 because of its smaller size, but would a more powerful router work better?
I ran one 1/4" 2 flute down spiral at 630 IPM through 3/4" treated plywood on a full run of 18,240 inches without breakage, in my CNC Router. I suspect that the problem is the router or the operatorís technique.
Router tooling breaks for a variety of reasons. You can push even small tools pretty hard if the conditions are right, but even a 15% increase in feed rate would not have made up for the cost of breaking, and the benefit would have been negligible.
The most common reason for a tool to fail is chatter, either in the work or the tool spindle. If either moves/vibrates/chatters, you are really pounding the tool and spindle to death. Some common causes for chatter are: poor work holding, worn collets, spindle runout (bent spindle, worn bearings, cheap router, etc) and bent tooling (solid carbide doesn't "bend"). Overfeeding the tool will lead to bogging down of the router, and probably a severe chatter just before the router stalls, and/or the bit breaks.
Using a larger router will help, as the additional mass will help cut down on chatter. Try a Porter Cable router, and try both common sizes. The 1-1/2 hp is pretty easy to handle, and is a fine hand tool. The larger 3 hp unit will add mass and power, and maybe a variable speed.
Always remember to thoroughly clean the tools shank, the collet, and the spindle every time you change tools. Any junk left behind may prevent the tool from seating properly, and it will not run "true", adding to the chatter/breakage problem.
Unless you are noticing a lack of power, you should look at the tool and work holding factors as the primary issues, and that may mean that your DeWalt is no longer rigid enough for the job. I have a lot of respect for some of DeWalt tools, but I do not know anything about your particular router. I do know that Porter Cable makes a good quality hand router that is very popular among cabinet makers.