The one excuse that makes the most sense is, "if we sell springs to a do-it-yourselfer, and he gets hurt installing it, we could get sued." I can sympathize with someone who wants to sell only to the trade and not bother with the risk of a spurious product liability lawsuit from an ignorant member of the public. But the lawn-mower dealers have figured out how to manage that kind of exposure, so this is not an absolute barrier to retailing garage door parts to the public. It doesn't explain why torsion springs at retail are virtually non-existent.
In my case, removing and replacing the relaxed springs required that I take down the assembly: torsion shaft, lift drums, and bearings. Doing that requires unbolting the center bearing plate from the wall, removing the drums from the shaft, and finally sliding the shaft back and forth out of the end bearings to remove the whole assembly off the wall. I am fortunate to have a lot of clearance in this garage to make the disassembly simpler. Tighter clearance to walls or ceiling would make disassembly a more difficult manipulation.
Insist on having any old parts returned to you, and have that noted on the written order before work begins. An honest and competent technician will not object to this. The evidence will establish whether you really needed the parts or not, and you can consult another opinion if you have any doubts. This tends to deter the parts-upsell scam, and protects you even if you know nothing about what you're buying while under the pressure of making a costly decision. If the old parts mysteriously "disappear", then you have reason to be suspicious.
Garage Door Installation – This includes the installation of a new garage door. Includes the door itself, the track, cables, springs, hinges, handles, locks and rollers. It is the complete service and installation of a new door. We inspect all the parts, make adjustments to fit your garage opening, and service all elements during the installation process. Plus, we check to ensure all parts are in proper working order after installed.
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.
Precision Garage Door of Seattle is the best choice if you are looking for garage door repair, maintenance, replacement and installation in the greater Seattle area. Our vast experience sets us apart from other competitors. Our experienced garage door specialists and our approach to finding and treating the cause of the problem is why we are the trusted name for garage doors in Seattle.
The third stage of garage door opener technology uses a frequency spectrum range between 300-400 MHz and rolling code (code hopping) technology to defeat code grabbers. In addition to transmitting a unique identifier for the remote control, a sequence number and an encrypted message are also sent. Although an intruder could still capture the code used to open a garage door, the sequence number immediately expires, so retransmitting the code later would not open the garage door. The encryption makes it extremely difficult for an intruder to forge a message with the next sequence number that would open the door. Some rolling code systems are more involved than others. Because there is a high probability that someone will push the remote's button while not in range and thus advance the sequence number, the receiver does not insist the sequence number increase by exactly one; it will accept a sequence number that falls within a narrow window or two successive sequence numbers in a much wider window. Rolling code technology is also used on car remote controls and with some internet protocols for secure sites.
You can expect to pay between $130 and $350 for a garage door opener, with most models costing an average of $200. The most expensive openers usually include extra accessories and smartphone controls, though most openers can work with a smartphone if you buy a Wi-Fi adapter such as MyQ. The types of garage door openers in increasing order of average cost are as follows: chain, belt, screw and direct drive.
Are you needing garage door repair? Has your garage door opener stopped working, or are you looking to boost your curb appeal? Whatever your garage door need may be, your local authorized Overhead Door™ Distributor is there to assist. You can find the nearest Overhead Door™ Distributor near you today by using our Distributor Locator to search your area.