Simple holder for extra soldering iron tips. This one was made specifically for the diameter and length of Hakko tips, but may work for other irons. The holes are 7mm in diameter.

The Hakko Soldering Iron Kit I use this with: https://amzn.to/2MQaQZd

The center has a recessed opening for a small can of tip tinner like this one on Amazon: https://amzn.to/2SLz5bZ

*I would recommend not using the tip tinner while it is in the holder as the tinner can become warm enough to melt the plastic while using.

This base on this design is not flat. If you wish for a completely flat base, sink the Z by 3mm below the slicer bed or cut 3mm off of the bottom in Slic3r (unless it already appears flat in your slicer. Some auto sink the 3mm since I exported it that way, some do not.)

If you want to mess with the design or adjust the dimensions, it was designed in Tinkercad. Here is the link: https://www.tinkercad.com/things/iCVpx21a2yd

Print instructions

Print with what ever settings you see fit.

I would recommend printing 'External to Internal' perimeters to preserve hole size tolerances.