Now 13 pounds of force must be respected when backed by many hundreds of foot-pounds of stored energy, waiting to be released. Holding this torque is equivalent to stalling a 3 horsepower DC motor. But holding and turning these handles does not require extraordinary human strength. Note that this maximum tangential force depends only on the weight of the door, and the radius of the drums, and is divided by the number of springs (some designs have only one longer spring, as mine did originally, instead of two shorter ones). Higher or lower lift distances imply more or less turns to wind the spring (and thus a different spring geometry), but not more force on each turn.

Unmatched or mismatched spring pair: You may find that you have a pair of springs that are different sizes. This mismatch may be a normal application, since the total torque on the torsion shaft is simply the sum of the torque contribution of each spring (indeed, very large doors can be lifted with 4 or more springs along the torsion shaft). The sum of the torque rates determine the lift; and dividing the torque among multiple springs does not change this. Some repair shops even apply mismatched pairs deliberately, since a few stock sizes of springs can be combined to fit a wider range of door weights than only matched pairs. For example, a technician may carry springs in increments of 20 lbs of lift, and when using pairs this allows a 20 lb increment in possible choices instead of 40 lb increments. Or, one spring from a pair may have broken and been replaced with a spring of equal torque rate but different size than the original.

Trading wire size for length, diameter, or cycle life: Now we are really going to save you some money, if you just recall your high school algebra class (and I don't mean that cute cheerleader who sat next to you). If you further understand the role of the 4th power of the spring wire size (letter d in the formulas above) in the numerator of the spring rate formula, and how to increase or decrease d to compensate for changes in length, diameter, and cycle life, then you're qualified for elite spring calculations. Matching springs is a matter of equating the 4th power of the proportion in wire size change to the proportion of change in the diameter or length or the product of both diameter and length. However, it is usually best to only increase wire size when substituting a spring, since this does not derate the cycle life. If you observe that the formula for bending stress is proportionate to the inverse 3rd power of the diameter, then physically a proportionate increase in wire size will result in a dramatic increase in cycle life of the 3rd power of that proportion. Trade-off example: Yawn with me while we ponder my original spring once more. Let's say I was in a fit of engineering mania, and wanted to replace my spring having a 0.2253 inch diameter wire (d = 0.2253) with a 0.262 wire version (d = 0.262). How much longer is the spring with equal torque rate, assuming we use the same coil diameter? The proportion of this change is 0.262/0.2253 = 1.163, and the 4th power of that is 1.83. This means the length must increase by a factor of 1.83 (again, not counting dead coils). Recalling that the length in Example 1 was 102 non-dead coils, the heavier wire spring must be about 1.83*102 = 187 coils, which when adding 5 dead coils and multiplying by the wire size to get the overall length, is (187+5)*0.262 = 50 inches, versus 24 inches in the original. So using this heavier wire more than doubles the length (and thus the mass and thus the cost). While the cost about doubles, the stress goes down by the inverse 3rd power of the wire size proportion, or 1/(1.163**3) = 0.64. Sress is favorably, non-linearly related to cycle lifetime (halving the stress more than doubles the lifetime), so this decreased stress should more than double the expected lifetime of the spring. While the up-front cost is more, the true cost of an amortized lifetime is much less. In short, per cycle it is cheaper. Ah, the wonders of engineering calculations! Conclusion: Observe that the stress formula (and thus the cycle lifetime) depends only on wire diameter (d) for equal torques. Thus the only way to improve cycle lifetime is to use heavier wire. For equal torques, heavier wire size, due to the exponents in the formulas, increases cycle lifetime much faster than it increases mass (and thus cost), physically speaking.


This is the electric opener which operates this door. I'm picturing it here because you pull the rope to disconnect the trolley, run the trolley under power to the fully-open position, and then disconnect power before working on the door. Then you should lock the door down with either the security lock or with Vise-Grips or C-clamps. This avoids the door lifting when you don't expect it as you are applying spring adjustments. It you were to foolishly overwind the spring without the door locked down, you could possibly find the door trying to leap up to the raised position when you aren't prepared. That would likely knock your grip off the winding rods, with potentially disastrous results. I like to work under the safety principle that serious accidents should be physically possible only when you make two or more stupid mistakes at the same time.

The Heavy Duty Chain Extension Kit for 10 The Heavy Duty Chain Extension Kit for 10 ft. High Garage Doors is required for reliable everyday operation of Chamberlain heavy duty chain drive models in 10 ft. garage door applications. Featuring a quick-install extension rail and replacement chain the kit includes everything needed for quick and easy installation. Includes ...  More + Product Details Close


Cost was $88 for 2 pairs of springs, plus $21 shipping. (I had to order 2 pairs to meet the $50 minimum order.) They came with new cones inserted as shown at that price, so I didn't bother trying to remove and reuse the old cones to save a few dollars. The cones are quite difficult to remove from old springs and to insert in new ones, and the spring supplier will have the right tooling to do that easily. That was the best price I could find on the Web at the time, and didn't seem out of line with what parts like this might cost at at the building supply (if they only sold them). Contractors buy these much cheaper in quantities; they're just an ordinary high-carbon steel wire turned on a winding machine. I also found Web sites asking a lot more money, obviously trying to cash in on search-engine traffic from do-it-yourselfers. Others report that some local dealers sell springs at retail, but at a high price that eliminates any economy versus having them installed.

Kevin gave 30 mins advance notice via text before arriving, and he was very friendly and knowledgeable about the Chamberlain garage door opener that we ordered on Amazon. I was pleased with the thorough model description provided, and customer reviews which helped with our decision making, and our package came on the same day that it was ordered! I liked the process of choosing 3 preferred appointment times, and receiving a confirmation email which included Kevin's picture. The install price was very reasonable, and I would gladly use your Home Service again!

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A torsion spring counterbalance system consists of one or two tightly wound up springs on a steel shaft with cable drums at both ends. The entire apparatus mounts on the header wall above the garage door and has three supports: a center bearing plate with a steel or nylon bearing and two end bearing plates at both ends. The springs themselves consist of the steel wire with a stationary cone at one end and a winding cone at the other end. The stationary cone is attached to the center bearing plate. The winding cone consists of holes every 90 degrees for winding the springs and two set screws to secure the springs to the shaft. Steel counterbalance cables run from the roller brackets at the bottom corners of the door to a notch in the cable drums. When the door is raised, the springs unwind and the stored tension lifts the door by turning the shaft, thus turning the cable drums, wrapping the cables around the grooves on the cable drums. When the door is lowered, the cables unwrap from the drums and the springs are rewound to full tension.[7]
Loosening or tightening the set-screws is the moment of most risk, since the end-wrench is a potential missile if you slip, and your hand is close to the cone. When the wrench is removed and only the rods are in place, it would seem that the worst that could happen is that the rod is flung out and the captive spring and cone rattle around, assuming you are keeping yourself clear of the rod's radial disk of rotation, and not leaning on the rod such as to fall into the apparatus were the rod to slip out of your grasp. The torsion shaft design has the virtue of capturing the mass of the spring and cones reliably on the shaft, preventing these parts from launching themselves as projectiles, even in an accident.
Garage door openers make it easy to get your garage open without the struggle or the hassle of facing inclement weather. The latest garage door openers have new features such as timed close, battery backup and improved energy efficiency. Sears carries top-of-the-line garage openers that can run much more quietly and smoothly than old models. With a keypad feature, you'll be able to get into your house using a secure four-digit code. With a few new batteries in your remote, you'll be opening your garage with the push of a button.
Weight and cost: The 24-inch-long spring has a calculated weight of 8.4 lbs, not counting the winding cones. At less than $1/lb wholesale, and $3/lb retail for fabricated steel products, this spring should sell for about $8 to $25 (2005 prices) each, depending on the market and source. Since a pair is required, the expected cost for a pair is $16 to $50.

Mechanical garage door openers can pull or push a garage door with enough force to injure or kill people and pets if they become trapped. All modern openers are equipped with “force settings” that make the door reverse if it encounters too much resistance while closing or opening. Any garage door opener sold in the United States after 1992 requires safety eyes—sensors that prevent the door from closing if obstructed. Force settings should cause a door to stop or reverse on encountering more than approximately 20 lbs (9.07 kg) of resistance. Safety eyes should be installed a maximum of six inches above the ground. Many garage door injuries, and nearly all garage door related property damage, can be avoided by following these precautions.
Garage doors cause injury and property damage (including expensive damage to the door itself) in several different ways. The most common causes of injury from garage door systems include falling doors, pinch points, improperly adjusted opener force settings and safety eyes, attempts at do-it-yourself repair without the proper knowledge or tools, and uncontrolled release of spring tension (on extension spring systems).

AE Door & Window is that company. You don’t survive and grow for more than 30 years of providing garage door repair service and installation without taking care of your customers. Our reputation for offering quality garage door service is unquestioned. It’s why we have an A+ rating from the Better Business Bureau and countless positive testimonials from satisfied customers.

We also offer garage door opener repair service. Many times, what appears to be a problem with your garage door is actually a problem with your garage door opener. Our professional technicians have experience with all major garage door opener brands, including the popular LiftMaster line of garage door openers. Whether your garage door opener is making too much noise, failing to turn on, moving too slowly or not opening or closing your door properly, we can fix it fast.


We’ve earned that reputation by always putting our customers first. When it comes to residential and commercial garage door repair services in northern Kentucky and Cincinnati, you’ll always get our best. That includes reliable installation, quick and responsible customer service, free and fair estimates on our work and 24/7 emergency service when you need it the most. We have designed our installation and repair services to make sure you get the most out of your garage door for as long as possible.


Smart garage door openers aren't as expensive or hard to find as you might think. In fact, no matter what smart home platform you're using, there is an opener that will work for you. Smart garage door controllers add convenience like remote access, voice control, scheduling and vehicle detection to your garage door. You'll never need to wonder if you left it open ever again. 
Establish an alternate entry to your garage or update an existing one with our selection of garage entry doors. With an entry door, you will lose less heat or air when you enter your garage to work. Our variety of garage and outdoor organization materials will help you keep all the items in your garage neatly and efficiently organized while our floor coatings and utility flooring will help ensure your cement garage floors last longer than if they were left untreated.
You depend on your garage doors to provide safety and security at your home or office. They are also great for enhancing your property’s curb appeal and increasing its value. With their many moving parts and how they operate, you must have access to a reliable service company when something goes wrong. Houston residents and businesses trust us to make sure their garage doors will work when they need it to.

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