Since we're using an 18-inch (1.5 feet) winding lever to wind each spring up to 29 foot-pounds, we must apply a maximum tangential force to the end of the winding lever of about 20 pounds. Later we'll see that the actual weight of this rather dense door is 238 pounds, implying a maximum tangential force on the winding levers of only about 13 pounds!
Install the stiffening strut on top of the top section of steel doors with the section lying flat. Then install the opener bracket that replaces the center bracket between the top two sections. While you’re working on the sections, protect them from scratches by putting carpet scraps on top of your sawhorses. Now, slide the rollers into the roller brackets.