After reviewing many different types of wool pickers I began to put one together. I liked the models that were longer, open ended, and with higher sides.
This box is constructed of 5/8″ plywood. It is 4′ long. The sliding top is approximately 1/3 the length of the box, 16″. Rather than dado a groove by which the slide is guided, I used 1″ lumber (thickness), 4″ lumber on the top and 8″ lumber on the bottom. The dimensions are 11 1/2″ wide and 12″ high sides, which coincided with the partial plywood sheet that I had. At either end at the top are all-thread rods that serve both to strengthen the box as well as to fine-tune the distance along the length of the slide. This allows it to experiences the least amount of play and to function most smoothly. As of tonight it works flawlessly. I also got the last boxes of uncoated common nails in the region, 3″ and 3 1/2″. Tomorrow I will finish this picker by sharpening the nails and adding them to cards, and then attach these on the slide and the floor. I am thinking that I will also add hardware cloth to the floor of the box to allow some debris to fall through during the picking process. This box is made entirely from scraps and used hardware that I had on hand, only the nails were purchased.