Introduction: String Trimmer Winding Tool

You CAN wind trimmer spools by hand; lots of YouTube videos. I find that it is difficult to wind evenly, and my fingers hurt from maintaining tension. My tool winds both halves at once - saves time, and improves consistency. And it’s less likely that you’ll slip and let the spool come undone.


Empty trimmer spool
Trimmer string (check diameter for your trimmer)
2 pieces of scrap wood - size is not critical as you’ll see
1 bolt with 2 washers and a nut, the diameter of your trimmer spool and at least 3” long

Step 1: Make the Tool

My tool is very crude; I whipped it up from scrap in about 20 mins in desperation. Anyone can do better; watch for new posts like “reclaimed pallet wood String trimmer winder,” or “live edge resin filled wood trimmer winder,” or even a 3-D printed project. ;)
So here are the basic parts:
- larger piece of wood (2x3) as the body;
- small piece of wood as the winder
- large bolt through the body and winder
- a few washers to minimize binding
- 2 small nails in the winding handle, to engage the trimmer spool.

Drill through the handle and the winder, so the long bolt will fit. Mine happens to be 1/2”

Now, the ONLY important part about this device are the nails: they must be centered relative to the bolt hole; AND they need to be far apart enough to engage the ratchet grooves under your trimmer spool. Not critical dimensions, but try to be close.

To be clear, on the winder, you need to measure out from the center so that your nails will catch the trimmer spool ratchets. Mark these points and nail the nails, leaving about 2 mm / 1/4” of the head protruding.

Step 2: Assemble Your Winder

Now that you’ve drilled the handle and the winder, and put your 2 nails in the winder, put it together as shown. You may need to enlarge the hole in the winder so it twists easily.

If your bolt is NOT a right fit through the handle, I suggest you add some glue: it is much easier if this bolt isn’t waiting to drop out all the time.

The 2 washers aren’t critical, but the reduce frriction and make it easier to twist.

Step 3: Wind the Spool

If you have a double string spool or single, it’s the same thing: measure out about 10’ of line ((or 2 lines) and attach it to the spool.
If you’ve never done this before, a simple overhand knot is enough, if you snug it down with pliers or your teeth.
Set the spool in your winding tool. You DID pay attention to the arrows on the spool, which tell you which way to wind the string? Me neither; you MUST twist your winding handle the OPPOSITE direction from the direction to wind the string. With the spool in your hand, this should become more clear.

I made 2 little notches at the end of the handle to guide the strings and help tension them evenly. Like this whole project, I’m sure there are more elegant solutions.

Twist the winder, just like all the videos about winding your own spools. Tie off the ends when you’re done.