Awhile back my wife bought a bow for our 5 y/o boy at a fair. All it was was about 2 1/2' of 1/2" pvc pipe with some twine and spray paint. Arrows were dowel rods with gigantic odd randomly shaped foam tips glued on. Well he had fun with it for about half an hour cause he couldn't hit anything consistently with it. I let him use one of my spare carbon arrows without a tip and he went to town, hit my deer bag target dead center at about 10 yards! I saw someone else here post about making a pvc bow and quickly I began to think of reshaping my son's piddley plinker. I stripped off the pipe insulation grip and hot glue, ditched the twine, and heated up our electric stovetop. I didn't have boards to make the limb jig so I used a couple wooden cutting boards to shape them. I had to reheat one limb because I didn't get part of it hot enough and it didn't take shape well, so it wasn't drawing back evenly on both of them. I gutted some paracord and after some trial and error, fixed my bowline knots (think that's the right knot name), trimmed and singed the excess, covered the limbs in camo cloth tape (more for safety if they shatter), and the grip in OD green duct tape. With my carbon 28" arrow and a 100grn field tip, and about a 10" partial draw, it penetrate my bag target about 2 1/2" to 3".
I'll be giving it back to him tomorrow after school, I'm pretty sure he'll dig it. I might see about posting some pics and/or video of him shooting it later.