Anyone who has laid out 100 ft or more of string line knows what a pain it is to wind it back up on those stupid plastic holders.
So I made one with a retractable handle that you can use a drill with any quarter inch screwdriver bit to wind the string up faster than hand winding.
I have put on over 300 feet of string on one of these with no problem.

Step 1: Materials List

You will need a 7 inch piece of 2 x 4 preferably a hardwood (I used a piece of scrap dunnage).
One quarter inch bolt (3 - 3 ½ in long).
One 5/16 inch threaded insert
One 5/16 inch bolt with the head cut off and nut.
One quarter inch screw bit adapter

Step 2: Cut Top Off Screw Bit Adapter

Cut â in off top of screw bit adapter, this will be your insert for the screwdriver bit.
Measure the diameter of the piece you just cut off, this will be for the size of the first hole to drill. (Mine was ⅜ in)

Step 3: Drill Hole

Center the hole on the side of the block of wood and drill a hole all the way through it's width. Don't put the insert in yet, set aside.
This hole will be for your handle.

Step 4: Drill Out Some Waste

Now you're going to drill two 1 ½ inch holes
2 inches on center on each side of the block.
This is to help with waste removal later

Step 5: Making the Retractable Handle

Now we're going to make the retractable handle out of the quarter inch bolt by rounding off the head using the drill press and a file.
You want to file the head down until it's just under ⅜ of an inch so it will slide through the first hole that you drilled easily

Step 6: Install Threaded Insert

Now we have to install the threaded insert.
First we drill a hole with an ½ inch drill bit on one side block through the handle hole a half inch deep.
Now this is where you use the 5/16 inch bolt that you cut the head off of.

Place the nut on the bolt then the threaded insert up snug against the nut then insert into the chuck the drill press.
Place the block under the threaded insert and use the drill press to thread the insert into the block of wood.
DO THIS BY HAND DO NOT TURN ON THE DRILL PRESS.
By using the drill press you will put the insert in straight
Now back out the bolt, by hand and the insert will be seated squarely

Step 7: Handle

Now place the quarter inch bolt through the other side of the hole of the block, it should slide smoothly through the threaded insert.
At this point you can cement the other insert, which you cut off the screw bit adapter (I glued mine in with gorilla glue)
Or you can do this part at the very end after you cut out all the waste and do the final sanding.

Step 8: Cutting to Shape

Now to get the final shape.
I laid out the two centre lines 2 ½ inches from the ends and 4 rough lines that angle out to the sides.
Then I cut out the waste to give me a rough shape

Step 9: Shape Middle

I used a saw to cut a quarter of an inch deep on each side of the middle on both sides. Then I chiseled out the wood between each cut. Be careful not to remove too much wood or the centre will not be strong enough.

Step 10: Finish by Sanding

Now all you have to do is sand off the rough edges and smooth to make it as pretty as you want.
You now have a string line holder with a retractable handle that you can use in your drill to wind back up.