This is not a new idea, but was searching on how to use the empty space in my 80/20 aluminum extrusion (used in my gentry) as an air tank. I am using pneumatic cylinders to assist in the heavy Z-column weight. Not wanting to run plastic lines all over my shop to get to the air tank reserve tank, I find a product that allows MiniTec series of aluminum extrusion (90x90, 45x90, etc.) to be used as an air chamber. Go to web site "minitecframing.com/Products/Pneumatic_Connections/Pneumatic_Connections.html" and there will be some Pneumatic Connections. I asked MiniTec what was the maximum air pressure with these Pneumatic Connections end caps. Their answer was 7 Bars (or 101.5 psi). That was good enough for me.
However, I made my own end caps (1/4" aluminum plate) and a rubber gasket (old bicycle tire inner tube), and threaded a mounting holes in the end of my 80/20 stock (3030, or 3" x 3"). Then, I drilled and tapped a hole in the center of the end cap, which I use to connect an air pressure gauge, an intake valve stem, and an outlet to my pneumatic cylinders (the reason for the air in the first place), all connected together. Pressto! I now use the 3030 on my machine as a pneumatic tank, which acts as the reserve air tank. When the pneumatic cylinders are compressed, the large volume reserve air in the 80/20 adsorbs in small change in the air pressure, thus keeping the air pressure in the pneumatic cylinders ranging from 75 psi to 76 psi in my setup -- essentially the same pressure thanks to the large air volume reserve in the 80/20.
Hope this helps someone.
However, I made my own end caps (1/4" aluminum plate) and a rubber gasket (old bicycle tire inner tube), and threaded a mounting holes in the end of my 80/20 stock (3030, or 3" x 3"). Then, I drilled and tapped a hole in the center of the end cap, which I use to connect an air pressure gauge, an intake valve stem, and an outlet to my pneumatic cylinders (the reason for the air in the first place), all connected together. Pressto! I now use the 3030 on my machine as a pneumatic tank, which acts as the reserve air tank. When the pneumatic cylinders are compressed, the large volume reserve air in the 80/20 adsorbs in small change in the air pressure, thus keeping the air pressure in the pneumatic cylinders ranging from 75 psi to 76 psi in my setup -- essentially the same pressure thanks to the large air volume reserve in the 80/20.
Hope this helps someone.