Home Pull Up Bar
Here is a home pull up bar that I constructed from some floor boards that were hanging around my home and I purchased 2 meters of steel tube and cut it back to a suitable length.
The wood is about an inch thick so it does not flex easily and the bar is a nice diameter to grip on and can handle my weight. I used long screws to attach the boards to the wooden framework in the corner of my workout room. The left side of the steel tube is screwed down to the wood and the right side is clamped down between the wood, so it does not move around.
So here are the photos of this home made pull-up equipment:

Detail of the technology involved:

You can maybe see that I used a 90 degree support on the right side bottom area to support the structure on the tatami mat. Also, I screwed a plank to a rib of wood in the shelving unit that extended out to anchor the vertical support plank. Well, I hope you get the idea. I live in an old Japanese home so I don’t have the luxury of strong door frames to hook a chinning bar to.

