Figured as a first attempt to make something in Sketshup and print it I'd try and turn this bow into a crude compound bow. Actually worked well. Just print the parts and affix onto 'Rubber-Band Bow and Arrow by j_siegel'. Some sanding may be required to get the pulleys to move smoothly. Slide the pully holders over the band knobs on the bow and arrow. They fit snug but some krazy glue helps keep them from moving at all when there is a lot of tension on the band. Try and get the center of the pulleys more or less in the center of the hole. Slide the pulley rod thru the hole in the mount and heat the end pushing down a bit to flare it out but not so tight that it doesn't move. There is a lo of leeway here and should be pretty eays to melt in place yet move. Glue the band holder into the smaller hole on the bow originally used to hold the filament guide. There should be a corrosponding hole on the other end to refit the guide rod (piece of filament), may need to be drilled out a bit. You also may need to snad down the rounded back of the clip so it doesn't hit the bow part to get it to fit into the hole. For the band I used thin elastic cord from the arts and craft store, works great. Tie one end to the small knob on he pulley mount and run it down, thru the holder in the middle under, and back up and over the other pulleys (not thru the center holder when going back up). Then run it in back down again thru the center holder. Pull snug and tie to the knob on the other pulley holder. ... also made a "Crossbow" mod which is pretty neat. Will post it soon.