Bookcase for ring binders

project: , published: by Maarten Tromp.

My dad was looking for a very specific bookcase. It had to be tall enough for 2 rows of ring binders, yet fit under the window sill. The bookcase had to go in the corner, but leave some walking space next to it. Such a bookcase is hard to find in a store. Right about that time I was looking for a woodworking project.

Since ring binders are wedge shaped, the bookcase could be made quarter round. That would leave the maximum amount of room to walk next to it and I loved the unusual design. Plus the whole thing would look like a quarter of a pizza, when looked at from the top. A maximum of 6 ring binders would fit that way. (A ring binder is 30 cm deep and 8 cm wide, so with r = .3 and w = .08 the number of binders that will fit on a shelf is: 2 π r 4 w 5.8 )

To squeeze in a few more ring binders, I moved the binders about 10 cm outwards and make the shelf a bit deeper. To prevent binders from being pushed all the way in, I raised the shelf behind the binders. Now a shelf would would hold 8 binders and I was at the maximum acceptable size of the bookcase.

The top of the bookcase, by requirement, acts as a side table. I have made a raised edge to prevent pencils from rolling off.

In industrial design I have always liked form follows function, where the contents dictate the shape of the container. In this design that translated to me as where the is no support needed, you could remove it. So I removed the shelf behind the binders. The shelves are now banana shaped. Then I realized that as long as the binders were supported on the edges, I could leave out out the centre section of the side panels.

With nothing left to remove, I started thinking about how to cut all the pieces. Cutting arcs with a jigsaw is tricky and I didn't want any wobbly sides. But recently I had bought a router (woodworking equipment, not a network device) and this opened up some new opportunities. So I used the opportunity to make router jigs for cutting all the arcs and side panels.

The bookcase is made of 15mm birch plywood and finished with linseed oil. To create raised sections behind the binders and around the top, I used an additional layer of plywood.

The bookcase turned out lovely, but the fact that I'm not a professional was obvious in some aspects. Ring binders are wedge shaped, but only when they're empty. Once they start filling up, they approach a block shape. And when the bookcase is filling up with heavy ring binders, the centre of gravity moves forwards quite a bit and the whole bookcase tips over to the front. That was now 'fixed' by making an additional support in the centre under the bottom shelf.

While the bookcase was designed for a constraint space, it has now moved to another room where there is a lot more space available.