This is another tool holder that is specific to my CR-10, but might be of use to someone else. My Printer space is quite cramped at 28" x 30". I've wanted to move the control box under the machine. This requires several modifications.
1) Raise the machine enough. 2) Extend cables to reach the new position. 3) Move the on/off switch to the front of the box.
This also precludes the use of the sit-on-top tool holders, so I modeled this so I can fit one on either side of the control box when places under the printer. It is specific to my most used tools. It bolts from two sides onto the 20x20 extrusion using M5 screws and extrusion nuts. I'll include a .igs file so others can alter it to suit their purposes.