A friend of ours who knits for a hobby, asked me to build some yarn boxes. She gave a link to a web site that sells the style she likes.
The web site sells them for $45 each, not including shipping. Here is a link to the web site.
I went into Sketchup and designed a similar yarn box. The 4 sides will be 1/2" thick stock. The bottom will be 3/16" thick Luan plywood. The lid will be 3/4" stock.
I have made this type of finger joint box before, including using 1/2" thick wood for the walls. On a finger box, for the bottom, it needs a 1/4 x 1/4" groove in the side walls.
You have to make a "stopped" groove that does not extend the whole length of the side board, or otherwise you have to fill the square by gluing in a 1/4x1/4 short length of the same wood.
This box design uses a rare earth magnet to keep the lid closed. I bought the smallest 2 sizes of magnets, and will probably use the smaller one on this project.
Most of the time involved with making a finger joint box is setting up the table saw finger sawing jig, then router table set-ups for the grooves for the bottom...........then any router work for the lid. I decided to make 2 boxes.............one a mix of dark walnut and light maple...........and one all walnut, except with a maple lid.
I used my old jig for 1/2" thick wood, which I wrote on to get.............on the dado set........the 2 outer with 2 inner blades to give a 1/2" wide cut.
The jig gets secured to the miter clamp with a clamp versus screws..............so you can easily adjust the right-left position of the jig with respect to the table saw........depending on whether your joints are loose or tight. I made a scrap piece of pine to use to do trial and error on the jib to set it up right.
I sort of forgot that on previous projects, you do get some tear-out of the wood when the dada blade breaks through the work-piece. When I dado sawed the fingers I got excessive tear-out on 1 side of the outer joint on each piece [the inner tear-out is hidden inside the box]. You can see the excessive tear-out on the RH side of the piece shown below..........
I decided to saw the joints slightly deeper on the side with excessive tear-out, and insert a piece of 3/16" thick Luan plywood behind the work-piece..........as a sacrificial piece. This worked great.
The good news is, my Dado saw blade set is a lower cost set. The bad news is, it does not give perfect joints, with respect to the depth of the joint. The depth cut is not straight across. I am accepting this trade-off of quality versus cost on this project.
My design calls for 1/2" thick fingers, so for a 4.5" tall wall, this would be 9 fingers. If your jig is not perfectly aligned to the table saw, or your saw cut is not exactly 1/2" wide, over 9 fingers you will get some error..............which I got on this project. I positioned the cut pieces to give the full 1/2" thick fingers on the top of the box..............and the narrower fingers on the bottom..............which works ok. If you want exact size fingers on top and bottom...........you should make your blanks taller, with an extra finger...............so you can table saw to exactly 1/2" thick on both top and bottom.
You need "stopped" grooves for the box bottom. If you don't stop them, the groove will be visible from the outside..............and you will have to fill it with a wood plug(s). I was able to do this on the router ok. I used the same approach on the top groove for the lid, that has to be stopped at the back.
Before you glue up the box, you need to drill the 1/4" diameter hole for the rare earth magnet, in the back piece of the box. If you wait until after gluing up the box, it will be difficult to get the bit at 90 degrees because the front side of the box is in the way. I will epoxy the magnet in place later.
I made the Luan bottoms, tested the fit..........then glued and clamped up the boxes.
I used the belt sander and the hand-held router with flush trim bit. The flush trim bit did catch once, and kicked off a walnut splinter, that I had to glue back on.
I used a 1/4" straight carbide router bit to make the edge lips that fit into the groove in the box.
I was going to use a bearing guided chamfer bit to put on the 45 degree chamfer.................until I realized it would not work........because on the RH and LH side of the lid...the wood is recessed and there is no place for the bearing to ride on. Fortunately, I had an old steel 45 degree chamfer bit........that I would use in combination with the fence.
If you want to avoid excessive tear-out, use a 3/16" piece of Luan as a sacrificial piece behind the work-piece.
If you want to end up with perfect 1/2" tall fingers on top and bottom of the box, make the blanks taller with an extra finger........so you can table saw to a perfect 1/2" high joint.
Remember to make "stopped" router cuts for the box bottom to fit into.............and/or the top lid.
There is a lot more man-hours of labor required to build these boxes than one would think. My hat is off to the company that can make a profit selling these for only $48!!