A stent delivery system includes a wire collection device which is constructed with a thumbwheel coupled to a collection spindle that is rotatable to collect a retraction wire about a varying collection diameter of the collection spindle. A proximal end of an outer stent-constraining sheath is coupled to the collection spindle by the retraction wire and a distal end of the outer sheath retractably surrounds a distally-disposed self-expanding stent. The collection spindle includes a substantially constant outer diameter greater than the varying collection diameter, and the varying collection diameter increases from a first end of the spindle towards a second end of the spindle along a spiral groove formed between the varying collection diameter and the substantially constant outer diameter in a manner that provides substantially constant rotating force on the thumbwheel, thereby accommodating changing resistance as the outer sheath is retracted and releases binding force of the stent.
