Depending on the design, you can know in advance how many turns are going to have to be unwound. Lifting a 7-foot door by winding a cable on a 4-inch diameter (about 1 foot circumference) drum requires about 7 turns, plus one extra turn to maintain cable tension at the top-of-travel. Maintaining tension at the top-of-travel is critical; without it the cable will jump off the drum, requiring a serious repair.
Modern garage door openers include basic to advanced features that improve safety and deter break-ins. Examples include an automatic stop if a descending door encounters a solid object such as the hood of a car and light beam sensors that detect the presence of an object -- or a person or pet -- and stop a garage door's downward movement before accident or injury can occur. Available security options include remote lockouts for when you will be away from home for an extended amount of time, remote codes that change after each use, and lights that turn on automatically when your garage door opens or if movement is detected inside.
The inside of the door panels bear a few dings, since filled with Bondo, from my teenage boys shooting hockey pucks. The streaks on the right that look like dinosaur claw scratches came from operating the door inadvertently when the rear doors of a van were open. The responsibility for these scars is all mine; they have also been Bondo-filled. We tend to use a lot of Bondo around our house. The crud on the walls and ceiling are cobwebs and dust infiltrates.
Traditional One Panel: These doors consist of one large panel which tilts to open by employing a spring mechanism to swing upward. The wood version is popular in the South and Southeastern US, where a milder climate keeps the wood from rapidly deteriorating. Traditional garage door designs include Cape, Colonial, Ranch, Tudor and Craftsman. The disadvantage is these doors require a lot of clearance to operate correctly. Sometimes repairs can be difficult because of the heaviness of the door or its inaccessibility. Average cost to repair tilt-up doors is $172.
The most common grade of torsion springs have an expected life of about 10,000 cycles. The hardened and tempered steel experiences tremendous forces each time the door opens or closes. Gradually, the steel fatigues with each flexure, and eventually cracks and breaks, usually releasing its stored energy in an instant with a horrific "sproing" noise or bang. If you average about two car trips per day, opening and closing the door a total of 4 times daily when you come and go, then that expected life becomes 2500 days, or only about 7 years. If you have an automatic opener, then if you're like me, you tend to cycle the door even more frequently, and can expect the need for spring replacement even sooner. Moreover, my three-car garage has three doors, so on average I can expect a repair job every few years. Over a lifetime, it is very economical to do these repairs myself.
Trading diameter for length: Observe that in the spring rate formula in the table above, factors D (diameter of coils) and N (number of coils) appear together in the denominator of the spring rate formula. Algebraically, given equal wire sizes, this means that the product of the coil diameter and overall length produces the spring torque, not the diameter or length alone. Physically, this means that you can trade off torsion spring coil diameter versus overall length in inverse proportions to maintain the same torque rate. Trade-off example: A spring with 2-inch diameter coils that is 36 inches long equals a 1.5-inch diameter spring that is 48 inches long, because the product in both cases is 72 (inches squared). This assumes that wire size is equal in the trade-off, and that you have not counted dead coils in the length. Service technicians use this principle to make quick substitutions for what's on their truck versus what you need. But if you understand this, you're ahead of many technicians who don't know this trick. Maybe now you can educate the next one you hire.
Sears garage repair technicians are fast, with same-day, emergency repairs available in most areas. We can replace garage door broken springs, rollers, cables, hinges, sensors and weather seals. We can also adjust garage door tracks and springs to make sure your door operates smoothly. Having problems with your garage door opener? We can repair or replace that too. Check out our line of Craftsman Garage Door Openers. Craftsman is America’s #1 brand of garage door openers! 1