Review on Apexstone 80N/18lb 7 Inch Gas Strut Cabinet Lid Stay - Set of 2 Gas Shocks Lift Supports Gas Spring by Corey Bigglesworth

Gas springs are ingenious devices that help open doors or covers with minimum effort and maximum safety. I purchased a pair of springs to hold open the doors of two small cabinets (one spring per cabinet) installed horizontally in the ceiling area above the existing wall cabinets in the laundry room. The installation instructions that came with the spring are not very helpful or complete. Doors and cabinets are about 9" tall, so I chose a 7" long Apexstone 80N/18lb spring to physically attach the spring inside. Cabinet. The small lower end of the spring plunger is attached to the cabinet wall at the bottom front of the cabinet and the upper larger end of the cylinder is attached to the door near the hinge. It took a little trial and error to find the correct position for the top pin on the door. Hoping to save others heartache, let me outline the logic and process I used to finally determine the critical position of this door pin: 1. The spring (cylinder) is installed when the door is open (in my case horizontally at the top edge of the cabinet), and the spring is fully extended, holding the door open in a horizontal position of approximately 90 degrees2. When the door is closed by pushing and turning, the weight of the door and the strength of the hand compresses the gas spring and gently closes the door in a vertical position.3. In the closed position, the door is held closed by the action (moment) of its own weight, which is stronger than the action (moment) of the spring around the hinge. In this position the spring has very little resistance.4. The main goal in choosing the correct position of the door pin is to balance the action (moment) of the spring with the action (moment) of the weight around the door hinge. It's like two riders balancing around the axis of a seesaw. One tab represents the weight of the door and the other simulates the force of the spring. The hinge is like a door hinge. The two actions are in equilibrium when the products of each rider's weight (force) and distance from the center of rotation are exactly equal. Applying this balance requirement to my situation, the product of the door's weight (Wd) times 1/2 its height (Hd) or the distance to the hinge must be balanced or equal to the product of the spring force (Fs). in the fully extended condition multiplied by the critical distance (Sd) of the top of the spring from the hinge. This means that the product Wd X (Hd/2) must equal the product Fs X Sd. If three of these quantities are known, the fourth can be found. In my situation, the manufacturer lists the spring force Fs as 18 lbs, a 1/2 door height (Hd/2) is 4.50 inches, and the door weight Wd is 4 lbs. Of the three quantities I can determine the fourth, the critical distance Sd required to balance the action of the spring and the door. The distance Sd is equal to Wd X (Hd/2)/Fs. Calculations Sd = 4 lbs x 4.5/18 lbs = 1 inch 6. Thus the spring pin on the door (critical distance Sd) should be about 1 inch from the hinge.7. I attached the piston end (bottom end) of the spring in the cabinet to the bottom right front corner and attached the top end of the cylinder to the door about 1 inch from the hinge. The bracket that accommodates this top end of the spring has long slots to set the critical distance.8. It turned out that I had to increase the critical distance to about 1.25 inches to allow for damper action in the cabinet hinges. I hope the attached photos help to clarify the wording of this detailed description.10. One final note: to separate the coil spring from its pivots, you will need to insert a small screwdriver under the chrome split ring into one of the two designated locations while pulling to pry the bushing out of the ball joint at both pivots. The springs work. great, almost magical. They prevent accidental closing of the door on fingers. Revain's execution is always top notch. A little tricky to install, but you will be greatly rewarded if you are patient and don't give up.