Step 1: Supplies Used
Neodymium magnets (pulled from Magnetix building toys)
Glue gun with glue sticks
Hacksaw (to cut the aluminum)
Drill with 3/16" bit
The length of the aluminum is dependent on how long you want your holder to be and how many nibs you plan on storing on it. Aluminum was used because it is softer than the nibs and will not mar them. Brass could also be used (I didn't because I don't like to look of brass)
How many magnets you need is also dependent upon how many nibs you plan on storing and how long your aluminum is. I found it works best if you use 1 magnet per nib spaced 1 1/2 to 2 inches apart.
I used hot glue because it is easy to use, easy to remove and cheap. You could use epoxy if you choose or even caulk but those all have long drying times.
Step 2: Mount Your Magnets.
IMPORTANT--Let the glue dry/cool before you lay the next magnet down as they will attract each other and lose their positions and likely make a mess when you try to fix them.
Step 3: Final Thoughts
If you pour enough glue in so that it is just over the sides of the channel walls it will prevent is from sliding if you set it on an inclined desk.
The magnets were placed inside of the track so that their power was diminished slightly. If you set a nib directly on a neodyme it will magnetize it and in time start to flatten it out or at least pinch the ink channel closes or pull it apart.