I needed to fit some shelving into a space that was too small for standard sized shelves and I could not be bothered making shelves from scratch so decided to use IKEA Expedit bookcases and modify them to fit the space.
The Bookcases were about 350mm to wide for the space I was filling so I cut them down to size. I also wanted one of the units to be suitable for holding CDs so I added some extra shelves on one of the bookcases using leftovers from the other two.
I am not going to show all the assembly steps. The key thing here is shortening the thick outside frame of the bookcase.
Basically I had this
Step 1: Goal
But I wanted this.
And I wanted shelves halfway each section as well
I assembled the thing first to mark where I wanted to cut.
Step 2: Cut Off End
First thing I did after that was make a test cut off the end so I knew what to expect. As you can see the frame is hollow with a cardboard honeycomb filling and a chipboard inner frame. I did the cut with a circular saw and although it wasn't as straight and square as the IKEA cuts, it was good enough.
Step 3: Inner Frame
There is an inner frame made of chipwood that runs around the inside of each section. At the places where the dowel lugs go it is double thickness.
Step 4: Inner Frame Double Thickness
The double thickness of the inner frame can be seen in this next photo
Step 5: Inside
The inside of these units is just a honeycomb cardboard filling which gives it a little support.
Step 6: End Sections
This is what it looks like at the ends and on the outside you can see the double thickness where the screws tap into.
Step 7: End Section 2
You need to pull this part of the inner frame out and re attach it to your cut down section. This is what it looks like when you pull it out.
Then you need to cut this down a bit because it is too wide to fit back into the hole (if you cut it off at the right place). Cut it shorter than the gap it is going to fit back into, that way you get a bit of adjustment when you fit it all together and things don't quite line up.
Also make sure you take all that cardboard off that is stuck to it or it won't fit back in nicely. I used a belt sander to do that.
Step 8: Rebuild the End
Then just knock the end bit back into place. So you end up with a shortened version of what you started with.
Step 9: Finished Shelf
The final Result looks like this.