KP block
thingiverse
When you need to glue up a miter joint you can use your bar clamps and these to ease aligning the corners. There are videos on Youtube on how to do it (search for How to Glue a Miter Joint) or you can go to Amazon and search for KP blocks Anyway, I made my own and they work great!
Download Model from thingiverse
With this file you will be able to print KP block 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 KP block.