That being said, I use a plunge router on my small portable table. I have a cheap set up but I can do anything for a guitar that I want on it. It is smallish so can flip it over to do the adjustments. It usually takes the most time to get it set exact. It has a safety cap to stop the bit if it breaks.
![Image](http://bestnetworx.com/uploader/files/141/router%20table.jpg)
Get the height set with these controls first. It is easy with the small table because I can push it down and measure on my lap.
![Image](http://bestnetworx.com/uploader/files/141/height%20router.jpg)
Once it is to the correct setting, lock everything in place with these bolts. Routers are notorious for vibrating loose with the plunge stop only.
![Image](http://bestnetworx.com/uploader/files/141/router%20lock.jpg)
Also, set the bit in the collet as deep possible to start. Then it can't move on you either. For what you are doing, and with your setup, you want a good bit. Like this:
![Image](http://bestnetworx.com/uploader/files/141/bit.jpg)
![Image](http://bestnetworx.com/uploader/files/141/downspiral.jpg)