Posted December 11th, 2015 at 9:58 am by Dan Musick
Most residential sectional garage doors use standard lift tracking and standard torsion hardware. However, commercial and industrial garage doors frequently use vertical lift tracking. Therefore, determining how to wind a torsion spring depends on many factors, including what kind of garage door you have and the width of your cable drums.
The door rises vertically a short distance and then moves horizontally in the tracks.
These doors use flat cable drums.
On standard lift doors, the formula is (DH/DC)+1, or the door height in inches divided by the drum circumference in inches, plus one. After winding the spring, you may need to add or subtract a quarter turn or more for the door to balance properly.
For example, on standard 4″ cable drums the circumference is equal to pi*4″, which is a little over one foot. As a result, the number of turns for springs on a 7′ high door is (7’/1.05′)+1=7.67, which rounds to 7 and 1/2 turns. On an 8′ high door, (8’/1.05′)+1=8.6, which rounds to 8 and 1/2 turns.
You can find vertical lift doors normally in commercial and industrial applications, such as on loading docks. These doors rise vertically the entire travel of the door.
The cable drums for these doors are fully tapered.
The formula for determining the number of turns on these springs is related to the formula (DH/DC)+1. However, because the drum circumference is not constant, calculating the number of turns to put on a vertical lift spring is much more difficult than for standard lift doors.
High lift doors rise vertically – some times a distance as short as a foot or more, sometimes more than half the door height – and then the door rides in the horizontal tracks. When the door is fully open, the lower part of the door hangs vertically in the vertical track extension.
High lift drums are partially tapered and partially flat.
The formulas for determining the number of turns to wind a torsion springs is based on the drum number, door height, and high lift dimension – that is, the distance from the top of the door to the center of the horizontal track.
As with the vertical lift doors, the formula for the number of turns on the springs is complex. Therefore, we rely on software or drum charts to calculate the number of turns to wind the springs. If you contact us, we can help you with this.
Clopay and TorqueMaster
A 7′ high Clopay EZ-Set door requires 11 full turns. For an 8′ high Clopay door, apply 13 turns. For a 7′ high TorqueMaster door, apply 16 turns, and for an 8′ door, apply 18 turns. Remember that you may need to adjust the number of turns so that the door balances correctly.
Other garage door torsion spring systems also use formulas that are similar to (DH/DC)+1. However, each one has other variables involved that complicate the calculations. If you want help finding the correct number of turns to wind your springs, do not hesitate to contact us.