Which brings us to our next thing: upgrading to a real spindle.
This is the 4/5hp spindle assembly from an X2 mini mill. The cast iron has been chopped down a bit to reduce weight, and the gear drive replaced with a belt drive for reliability and sound. There are a ton of advantages to a real spindle over a crappy router, too many to list, but here are a few big ones:
1: Play. There is almost none, so chatter is cut down drastically. This is better for your finished product and better for your bits.
2: Torque. A trim router has none. A VFD controlled motor maintains most of its torque at any rpm.
3: Collets. Rather than a crappy, 1/4" only 'collet' (which is really a badly designed chuck), this uses R8 collets (I also have an adapter to go to ER32 collets). This means flexibility in what bits I can use, less chance of them coming loose, and less runout.
4: Sound. Routers sound terrible, this has a pleasing hum to it.
5: Motor placement & type. Since it's far enough away from the business end, and mostly sealed off from the elements, this will make running coolant much easier.