I am gonna show you how to make a Bearing Edge to a Drum Shell. It can be a great improvement on the sound of your drums if it is done well, if you want to learn more about Bearing Edges, I'll let you a few links in the description.
There are a lot of types of Bearing Edges, In my case I am gonna go with a 45 degrees inner angle and 30 degrees on the outer side.
You can easily find a lot of flush trim router bits like this with different cutting angles, but don't worry if you don't have any, you can also tilt the Router using the same bit for all the cuts and an easy to make Bearing Follower like the one I made for my Table Saw.
I am gonna use a piece of wood to draw the correct angle, in my this case 30 degrees. And then, tilt the Router Holder.
I need to add a new threaded insert because the one I have is too close to the Router bit.
Change the tilt again, this time to 45 degrees and also setup the bearing to the desired depth.
Use a 120P sandpaper to round it a bit...
...and this is the final result.