Was needing something to help apply magnet to projects.

After you glue your own magnet in the empty slot, you then can use it to hold your other magnets in place as you push it into the 3D printed hole. You get no glue on your finger, just wipe the tool off afterwards.

The slot to glue your own magnet is 12 mm wide by 13 mm deep, so you can use your own size magnet.

You will have to print two of these, one with the magnet flip so you can keep your polarity right.