Drill Corner Jig
cults3d
This should help you drill holes at a 90 degree angle on corners. I needed to do quite a few and did not want to worry about holding the drill perfectly each time.
Download Model from cults3d
With this file you will be able to print Drill Corner Jig with your 3D printer. Click on the button and save the file on your computer to work, edit or customize your design. You can also find more 3D designs for printers on Drill Corner Jig.