I was going to wait until I had a final version, but decided to go ahead and post pics of the prototype since it is close to a final design.
I picked up some 110V solenoid pneumatic air valves off Ebay. Like most on Ebay they had been removed from some automated machine and came in a block of 10 valves. This pic shows the valve block, one of my 6" manual blast gates, and a homemade cylinder. I subsequently abandoned the idea of making my own cylinders. The gates are operated by air pressure from my shop air- but only need about 20 psi.
These particular valves have threaded outlet ports on the back of the valve body, but the sides have open air passages. While two of the passages are for exhaust ports and can remain open, one passage is for the air supply, so I built covers from some scrap acrylic sheet. I drilled holes for the exhaust and pressure passages and mounting screws, and threaded the pressure passage hole for a fitting.
I purchased double acting cylinders, again from Ebay, made a bracket from aluminum, and mounted a cylinder to one of my blast gates. For testing, I mounted the valve to the front of my jointer just below the blastgate. The solenoid valve is activated by the machine power and controls shop air which then operates the cylinder. I still need to make some refinements, but as it is, it works great. Actuation time is less than 1/2 second using less than 20 psi and MUCH QUICKER with higher pressure. I will eventually shorten the air connection hoses, run permanent low pressure shop air lines, and add a micro switch to turn the DC on (but not off- I don't want it to cycle too quickly). Here are some pics of my freshly painted prototype autogate in action.
I picked up some 110V solenoid pneumatic air valves off Ebay. Like most on Ebay they had been removed from some automated machine and came in a block of 10 valves. This pic shows the valve block, one of my 6" manual blast gates, and a homemade cylinder. I subsequently abandoned the idea of making my own cylinders. The gates are operated by air pressure from my shop air- but only need about 20 psi.
These particular valves have threaded outlet ports on the back of the valve body, but the sides have open air passages. While two of the passages are for exhaust ports and can remain open, one passage is for the air supply, so I built covers from some scrap acrylic sheet. I drilled holes for the exhaust and pressure passages and mounting screws, and threaded the pressure passage hole for a fitting.
I purchased double acting cylinders, again from Ebay, made a bracket from aluminum, and mounted a cylinder to one of my blast gates. For testing, I mounted the valve to the front of my jointer just below the blastgate. The solenoid valve is activated by the machine power and controls shop air which then operates the cylinder. I still need to make some refinements, but as it is, it works great. Actuation time is less than 1/2 second using less than 20 psi and MUCH QUICKER with higher pressure. I will eventually shorten the air connection hoses, run permanent low pressure shop air lines, and add a micro switch to turn the DC on (but not off- I don't want it to cycle too quickly). Here are some pics of my freshly painted prototype autogate in action.