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.
Lift cable placement: On the standard residential door mechanism, the loops at the lower ends of the two lift cables loop over the two bottom roller shafts which project from the bottom bracket on the door. The upper cable ends fasten to the drums using one of the methods described above. The drums are positioned along the torsion shaft such that the inner edge of each drum is approximately over the edge of the door. The cable winds onto the drum from outside in, so at the top of travel the cable is winding onto the inner edge of the drum, vertical from the edge of the door where it is looped over the roller shaft. As the door is lowered, the cable winds out to the outer edge of the drum, and thus is a bit out from the vertical, but the cable still falls in the gap between the guide rails and door edge. My cables rub and slap on the rails a bit, but after 30 years and many 10,000s of cycles, they don't seem to have worn at all.
Looking for something powerful but don’t want it to be too loud? This garage door opener from Chamberlain is a great option. Featuring an exclusive Motor Vibration Isolation System which eliminates vibration for reduced noise, this is a good choice especially you have an attached garage with rooms above the space. It also has MyQ enabled technology that allows you to monitor and control the opener via your smartphone with an extra purchase of the product. You can set the opener’s timer to close the door one, five or 10 minutes if you forget, and it has sensors to make sure it won’t close if something is in its path. It comes with a lifetime motor, lifetime belt, five-year parts, and one-year accessories warranty.
Note the left winding cone with red spray paint. This shpritz of paint is applied to create fear and doubt in the mind of the do-it-yourselfer. Sometimes it is a color code for the wire size (using a DASMA standard, red indicating 0.2253 inch diameter wire). Sometimes it indicates the winding direction: red may indicate right-hand winding, but don't rely on that; do you own independent analysis. Sometimes it is a manufacturer's private code for another dimension than wire size. This color code is for the installer's information when the spring is new; I would not depend on interpreting the color code properly on an old spring, since one can't be certain of a correct interpretation without documentation from the original supplier.
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.
Even if one could somehow stretch and clamp the springs to the proper extra length, the process would still be more trouble, and there would be little or no reduction of risk. Lifting the full weight of the unsprung door by hand and clamping it in the raised position is dangerous in itself, and creates the same amount of stored energy as winding the springs, ready to slip out of your hands. Many doors won't travel far enough up the track to provide clearance to access the springs. You're also going to have to deal with winding stiff steel cables onto both lift drums at once without any resistance to maintain tension. Finally, even if you managed to complete the installation with the door raised, you then have to lower the massive door against an untested balancing torque. If you've made a mistake, then that massive door has nothing but your skeletal force applied through your meat clamps (hands) to prevent it from falling down and crushing whatever is in the way (perhaps your feet?).
Checking if the lift drums need resetting: The old position of the lift drums on the shaft may have slipped or otherwise lost the the proper position, requiring a reset of the drum position on the torsion shaft. You will also reset the drums if you are replacing the lift cables, since the new cables will not exactly match the length of the old ones. Problems like uneven tension on the cables, or a tilted door, or a door that doesn't easily stay aligned with the tracks, can be due to an improper "set" of the drums on the shaft. So one shouldn't assume the old positions are correct. Setting the drums on a "fresh" part of the shaft will avoid the possibility of damaging the shaft from retightening in the same dimples.
The "safety issue" trick: Another tip-off is the use of language like "safety issue". This is meant to trump any objections you might have to a costly repair bill. Don't be manipulated by the suggestion that you are risking disaster if you don't buy something expensive. Even if you think the risk is genuine, get another estimate, and tell the second repairman you are skeptical; every technician loves to prove the competition made a mistake.
The parts, parts, parts trick: You might be told you need new rollers, cables, drums, bearings, etc., when you don't, or at highly inflated prices. Good questions to ask when first calling for service include, "How do I know you will only charge me for the parts I actually need?", and "If you don't have all the parts I need, what will you charge me to come back?"
We are a family owned and operated, local garage door company in the Carlisle area that believes in attention to detail and an emphasis on customer service and satisfaction. We even offer same-day service because we know that when your garage door isn’t working the way it should, you need it fixed fast. We offer affordable rates that will fit your budget, and we’re confident you won’t find another garage door installation company in Carlisle or the surrounding areas with the same dedication to our customers and the quality of our work at the affordable rates we offer our clients.