So I need a clamp, specifically a corner clamp jig.
Google finds this:
And I was inspired by this fireball tool mega square but they are $190.00 for a 12 inch. Yes, made of cast iron, but I was curious if I could make this myself. For one, a MDF clamp would be just as straight, but a lot lighter.
It did take 45 minutes to draw in Adobe Illustrator. This was a bit hard because I wanted all the lines to be exact and symmetric. I used the measure tool to verify all the dimensions and locked into their grid to make sure all the angles were correct. The pathfinder tool was super helpful in making the complex shapes.
I exported this as an SVG and set up the toolpaths in Carbide Create and selected a #201 1/4 inch endmill that allowed me to use a 0.3 inch single pass cutting depth at 18000 rpm and 80 inch/min speed. Details here and full tooling support.
My toolpath simulation:
I was blown away with how fast the MDF cut (3/4 inch in three passes) and it took about 6 minutes to make the whole piece.
The final product exceeded my expectations, super clean lines and I tested this on several boxes. It really did make clamping corners easy.