I make no recommendations of, and have no connection to, any of the following suppliers. These are just those whom I have learned about from my Web searches, from correspondence with those sending email about their experiences, or directly from the suppliers. I have removed several contacts that were generating complaints to me from dissatisfied customers. I have added this list to this page due to all the email queries I was receiving daily asking where to obtain parts. If you are a supplier and would like to be added to the list, see my email address at the end of this page.
Most doors come with electric door openers. After a while these openers malfunction and need to be replaced. If your opener is broken, you're in luck. These repairs don't cost very much and can be replaced easily. You might even be able to do it yourself. Learn how to replace your garage door opener in 15 minutes https://www.youtube.com/watch?v=HeaR6Yhx6IY.
Speed of a falling door:: Physics tells us that the transit time of a free-falling body is sqrt(2x/g), where x is the length of the fall and g is the acceleration due to gravity (32.2 ft/sec^2). If this typical 150 lb door were to fall an equivalent of 3.75 feet, this falling time would be sqrt(2*3.75/32.2) = 0.48 seconds (480 milliseconds). The terminal velocity is gt, or 0.48 seconds * 32.2 ft/sec^2 = 15.5 ft/sec = 10.6 mph.
Extension spring systems should always be restrained by a safety cable that runs through the middle of the spring, tying off to a solid point at the rear and front of the horizontal door track. Extension springs represent a hazard to bystanders when a spring, pulley, or cable breaks under tension. Metal parts from extension spring systems can suddenly be launched.
And for some extra features, you'll appreciate accessing the system through the MyQ smartphone app. You can set up this Chamberlain opener to automatically close the door after 1, 5, or 10 minutes, which is great for people who are a bit forgetful. We also really like the motion-detecting control panel, which turns on lights whenever it records nearby movement.