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Making a Handle for the Ratcheting Screwdriver

This page documents how I designed and made a handle for the WoodRiver 7-Function Ratcheting Screwdriver. Woodcraft sell a "Turning Kit" for $8.50, Item # 163336, Model JS4300A-4, that includes everything you need except the handle material. The instructions (follow the link on the product page) state that 2" x 2" x 6" turning stock is required, which you can buy separately or make up from what you have on hand. In my opinion, 1½" square stock will be fine as a comfortable handle will be 1¼" or a little less in diameter. The tools that you will need are also listed, but I have made a few changes to this in my design (see below).

Designing the Handle

Reviews of the screwdriver kit sometimes complain about the lack of a ferrule. This metal band's purpose is to hold together the wood where it surrounds the mechanism so that it does not split apart when a large twisting force is applied. The woodcraft instructions have you drill a ¾" diameter hole 7/8" deep in the end of the handle. For comfortable operation of the ratchet control ring, the diameter of the wood here will be about 1 1/8", which leaves just 3/16" of material around the hole. Presumable, Woodcraft feel that with a "liberal amount" of epoxy this will hold together, but I am not confident of this. For appearance, comfort and balance, I want to begin necking down the handle not too far behind the ratchet control ring and this will make things worse. So, I'm changing slightly the way that the mechanism fits into the handle to increase the thickness of the wood surrounding it. This change also drastically reduces the amount of epoxy needed and lowers the chance that it will end up where it shouldn't be (for example, in the control ring).

Prepare the Turning Blank

• There's no point in starting with a turning blank that is vastly over-size just to remove a lot of wood on the lathe. In fact, I used to use my table saw to make the blank octagonal and further reduce the lathe work, but as I've gained a bit of confidence I now leave it square. For this project, the blank needs to be 1 3/16" to 1¼" square and 5¼" in length. I made my guide for marking the holes (see below) to be 1.215" square (for no good reason) so I try to be close to this.

Making the Hole for the Screwdriver Mechanism

• Mark five points on each end of the blank using a carefully prepared guide. Align the guide with the end of the blank, insert a 1/8" brad-point drill bit through each hole in turn and give it a tap with a small hammer. If the marks look to small to work with, enlarge them with a center punch after removing the guide.

• At the headstock end only (the end of the handle that will receive the mechanism), drill holes at the four outer marks with a 1/8" brad-point drill bit to a depth of 3/8".

• Drill the center hole at the headstock end to a depth of about two inches with a drill that will make a suitable guide for your 5/8" Forstner bit in a following step. For me, this turns out to be a 3/32" drill. Don't drill so large that the bit flops about in the hole; that's no use at all.
• Drill the center hole at the footstock end to receive whatever center device you're going to use. For me, a 1/8" drill to a depth of about 1/8" works. Don't drill too deep or you'll end up with a hole in the bottom end of the handle. However, if you do, you can use an idea my wife came up with and insert a brass screw, chop it off and sand it flat so it looks like a deliberate design feature.

• Bore out the center hole at the headstock end with a 5/8" Forstner bit to a depth of 13/16".

• Deepen the center hole at the headstock end with a 7/16" brad-point bit to a total depth of between 2 1/8" and 2 1/4".

Loading the Blank into the Lathe

• The wood blank is now ready to turn, so it needs to be loaded into the lathe.

The lathe headstock is shown in closeup in a photograph on the right. The drive widget can be clearly seen with the spur drive engaged at left and insertion into the handle blank at right.

The lathe footstock (tailstock) is shown in closeup in a photograph on the right. In an earlier step, I drilled a shallow 1/8" diameter hole in the middle of the workpiece. The center spike engages in this hole to hold the tail end steady and allow the workpiece to rotate about the axis. Before running the spike into the hole, I fill it with a dab of Minwax paste finishing wax to act as a lubricant. I advance the spike until it exerts firm pressure but don't tighten it too far. I set the jam nut to prevent the spike from loosening due to vibration. From time to time, I check that the tail is still firmly held and that heat is not being generated by excess friction.

Turning the Handle

• The first step in turning the handle is making the blank round. Here I am doing exactly that in the photograph to the right. When this is done, it will be necessary to move the tool rest inward.

• Once the blank is round, it needs to be reduced to the desired diameter. For my design, this is set by the section of the handle just behind the ratcheting mechanism and also the parallel part of the handle that sits in the palm of the hand (they are the same as there is no reason for them to be different). For easy access to the ratchet control ring, this diameter needs to be about 1 1/8" and I seem to end up at around 1.17" which works out fine. Depending on the starting diameter of your blank, you may need to move the tool rest inward again before continuing. I start with blanks sawn to about 1 3/16" square so I do not need to do this.

• Now the desired shape of the handle needs to be established. There are only two differences from a simple cylinder. One is the "neck", which allows the thumb and fingers to be closed tightly so as to push forward on the "shoulder" of the screwdriver. The other is the round base which will sit at the bottom of the palm of the hand. Both shapes are whatever is comfortable to hold and pleasing to the eye. The diameter of the handle at the narrowest part of the neck is about 0.89", which is as close as I got to my informal goal of 7/8".

• When the shape is complete, the handle can be sanded (while spinning on the lathe) with 150, 270, 320 and 400 grit sandpaper (or some similar sequence). I then stop the lathe and make a few passes along the length of the handle with 400 grit paper to finish off.
• As the round base is formed, a nub is left for the spike of the footstock to continue to support the workpiece. I find a ¼" chisel useful (in place of a proper parting tool) to reduce the diameter of this nub to ¼" diameter (or less, as I gain experience). Then I remove the handle from the lathe and carefully saw off the nub. Next, I present the bottom of the handle to my belt sander with 220 grit abrasive to remove what's left of the nub and smooth out the shape. Finally, I hand sand with 270, 320 and 400 grit to give the same surface as the rest of the handle.

Finishing the Handle and Mounting the Mechanism

• Having sanded the handle down to 400 grit, it is ready for the application of a finish. At present, I use Danish oil.
• After the oil has dried, the handle can be assembled to the screwdriver mechanism. But, first, the mechanism needs to be modified because of the design changes in how it fits into the handle. The part that goes into the hole in the handle is a cylinder about 5/8" in diameter with four sets of protruding fins. In the original design, the whole thing went into a ¾" hole and the considerable empty space was filled with epoxy. In the new design, the hole is reduced to 5/8" and closely fits the cylinder. The four fins closer to the ratchet control ring fit into the slots left by drilling four 1/8" holes before boring the main hole. The second set of fins further from the ring need to be removed. I just file them off as the material of the casting isn't very hard to work. While I'm at it, I file off the casting seams and generally clean things up.
• Cut chamfer inside neck to clear structure also act as well for excess epoxy.
• Epoxy.

Notes

The first handle I made was curly maple. It weighed 33 grams and the screwdriver felt badly balanced when the mechanism was fitted (too light at the handle end) so I've not epoxied it in.

The second handle I made was cherry. It weighed 45 grams and had a better balance, so I have epoxied this one in.

The third handle I made was from glued-up canarywood with padauk and walnut accents, supposedly to hide the glue line. It weighed 46 grams. I found it more difficult than the earlier two, perhaps due to the wood's workability but perhaps just due to incompetence. I repeatedly got an unintentional spiral cut from the very bottom up the curve to the sides.