After watching this video, you can download the free PDF document and make it easily. There are many 90 degree corner clamp videos on youtube. But this is a little different from what I did, let's see, do you like it?
Making Video :
Go to this video's Youtube page and make a comment.
PDF Download : Right Angle Corner Clamp Making
Important: If you want my PDF documents to continue to remain free, please like and comment on the Youtube video.