A wire collection device for a stent delivery system includes a plurality of nested wire collection drums with a first drum concentric in a second drum. A thumbwheel coupled to the first drum can rotate to actuate rotation of the first drum to collect the retraction wire around the diameter of the first drum. A catching mechanism can rotate about the first drum to engage a catch portion of the second drum and actuate rotation of the second drum to collect the retraction wire around the outer diameter of the second drum. This increases the collection diameter of the retraction wire to provide a mechanical advantage for sheath retraction.
