For your 29-inch long, 3/4-inch diameter slow rise shade that is not retracting, the internal spring mechanism likely needs replacement. We recommend the Irvine Large 3/4" Spring, which measures 23 3/4 inches in length and is designed specifically for 3/4-inch diameter slow rise shades. Additionally, the Irvine Shade (Auto-Stop) 3/4" Position Fixer can help ensure proper shade functionality and smooth operation. These parts are compatible with your shade and will help restore smooth retraction. If you need guidance on installation or further assistance, feel free to contact us.