With many tools mobile, use flex hose is a must, and 4 inch flex hose is very hard to store. Fastcap come up with the great solution about storing 2.5 inch hose with a reel. Unfortunately they don't sell one for 4 inch hoses.
So I made one for 4 inch hoses. All the stretcher pieces are made from 2x4, can be cut to any length. The reel connects to the bracket by a 4 inch lazy susan bearing. After I made the reel, I realize if I integrate a blase gate into it will be very useful. And since the reel is mounted at the ceiling, I made a pivot blast gate with long handle, so I can still operate it with arms reach.
After couple month of use, I really like the reel, it easily put away the hose when I'm not using it. And I only need to pull out the length I need to reach the tool, so there's no hose on the ground. But to reel it back it a pain, so I cut out some gear and made a motorized one. The first version is using wind shield wiper motor, it is a bit slow and it does not keep track of the position of the reel. So I made the second one out of stepper and arduino. Surprisingly the price of the Stepper+driver is almost the same as the wind shield wiper motor + a speed control board. I'm still working on the code, but now it knows the position, and can move the reel to any position between 0(all retract) to 6 turns (all hose pulled out).