Here is an easy way to make more string for your Yo-Yo, just like the kind you would buy from Duncan. String is about 38 inches in length. This method can even be modified to make rope.
I did not come up with this method myself, I found a video on YouTube. I just improved the method a bit.
Update July 22 2011:
Wow, I got featured and on the front page. Thanks Instuctable editor(s). To bad I never updated the pictures like I keep planing to do.
Step 1: Gathering Materials
*Block of Wood about 5.5 inches X 8 inches
*Marker or Pencil
*Few nails (Finishing)
*Wood floor or long wood board that you can mark up and nail
Step 2: Preperation
NOTE: use scrap wood or a wooden floor in your garage to mark and nail on , NOT THE FLOOR IN YOUR HOUSE.
Mark out the following;
Start With a Line and Write DRILL next to it. This is where the drill will be placed.
Measuring from previous line and go 107 Inches (8ft 11 inches) and draw a line and write START. This is where the block will start.
From START measure 24 inches (2ft) toward DRILL line and write STOP. You guessed it, this is where the block will stop.
Now from STOP measure 38.5 inches towards DRILL. Write 1/2.
Step 3: Now Nail It!
Step 4: Now to Make the Block
NOTE: Grind off head of nail so string will slip on or off.
Last place hook in drill chuck.
Step 5: Now Lets Make String!
Place drill at drill end.
Now tie the string end to small nail in corner.
Loop string around hook and large nail four times.
Tie end of string together with end on small nail, cut off excess.
Step 6: Twist
Place drill in forward such that it will drive a screw in or drill a hole. Turn on drill and run until block hits STOP line.
Note: Plug drill in. Very Important!!
Step 7: Almost There
Take string off hook attached to drill so that you have an open loop at the end. Keep it taut or it will tangle up!
For help getting string off hook see video.
Place drill in reverse, pinch string about 1 1/2" from hook and run drill slowly until an opening appears. Place finger in and remove.
Step 8: Finishing It Up
Pull string looped around 1/2 nail and continue to keep it taut. Facing block spin end in your hand in a counter clock wise movement SLOWLY. String should naturally want to twist that way.. Twist until string doesn't want to twist anymore.
NOTE: String still might twist around still when you let go.
Measure to length, tie knot and go Yo!
Step 9: Extra
Here is the "machine" I built to make string easier. I have a few improvements to make and will post them when done.