Shapes Toy Box (CNC Router)

For my young nephew's Christmas present I decided to make a toy box with different shaped holes and shapes. Instead of just buying one from amazon or going to a toy store I spent my time in CAD designing my project and then cutting it out on a CNC Machine. The box includes a top with a slot for a lid. I also manufactured shapes for the box. I took inspiration from a design I saw online

There were pieces of 1/2 " and 1/4 " plywood laying around that I used for the box. The 1/2" plywood was used for the sides and bottom of the box but the 1/4 " plywood was used just for the lid of the box.

I made a couple of drawings for different designs of boxes. I had rough drawings of what I wanted to make and a couple of different designs for what it could look like. I included different box shapes and different lid designs. I then made a rough prototype out of cardboard to see if I like the dimensions of the box. The prototype included a small design problem that I fixed. The problem was that the holes in the box had sizes that weren't tested enough. This problem allowed all the shapes to fit into the square hole. To fix my problem I made the square hole smaller and made the pieces taller.

In fusion 360 I started with designing a roughly dimensioned box. I added tabs to the sides of the box for easy assembly. After that I made the lid and the slot in the sides of the box. After finishing the rough design of the box I started to add the holes for the shapes. I used a variety of different shapes, all about the same size, for the shape holes. After putting the holes into the sides of the box I made the actual shapes themselves. For the shapes I dimensioned them a little bit smaller than the holes and I extruded them to a length of 1 1/4 ". These shapes would fit into the holes easily but only in the correct orientation.

After making the 3d model for the box I used the manufacturing section of Fusion 360 to create g code for our CNC Router. I used multiple setups for the different sized pieces of wood. The three setups included multiple contours for the parts. I used 2 2d contours-both using a 1/8 " flat endmill for the cutting tool-for the sides of the box. The two contours ha different depths one for the slots and one for the actual sides and holes in the box. After making the cam for the sides of the box I started the cam for the shapes. The shapes used stock with a larger depth so I had to readjust what tool I was using. I originally started with trying to face the stock down to the right dimension but later on in the process I decided that that was unnecessary. I used one contour for the shapes-this time with a 1/4 " flat endmill for the tool. The lid of the box was the easiest to make and only took a couple of minutes.

After creating the cam for the parts I brought it to our CNC router. I started with cutting the lid out of a small piece of scrap lying around. I used a CNC router to cut out the lid of the box. After cutting out the lid I sanded down the sides and faces on our belt sander. I finished the lid by making sure it was smooth. After the lid I machined the sides of the box. This took a lot longer than the lid, around a half hour of manufacturing time. The CNC router cut out the pieces and I used the pieces left behind from manufacturing the holes as the shapes for testing. I tested the holes and found that the holes on the lid of the box where way bigger than they should be. This made it possible to put all the shapes into one of the three holes on top.

The tabs on the sides of the box had no tolerances on the corners meaning the tabs didn't fit together that great. The tabs were too big for each other and the corners weren't square making the fit for the tabs even worse. By hand, I filed down the sides and corners of the tabs until they fit together snugly. I hammered down the sides into each other removing the need for wood glue. The lid of the box also didn't slide into the slot perfectly so I further sanded down the lid of the box until it could slide easily. I sanded down all the sides of the box and the corners of the box until smooth. The box was now complete and could be used as a toy.