Pen cup holder

Cut out the required parts. Make sure the flexible wall is nice and flexible without defects or it may break during assembly.

You can add text or image on the full circular piece for a nice message if making as a gift.

The two pieces with notches are the same. Add the other two full pieces to each one and clamp them together. These pieces hide the joints and make for a nicer overall look.

This is the most difficult part and it will require a bit of patience and possibly force.

First, shape the wall in a roughly circular part. I used some tape to hold it together.

Add glue to the bottom bracket where it will join the wall.

Then slowly start adding the wall. I started in the middle of the wall part and inserted one end first and then the other as in the picture. At one point you will likely need to remove the tape to open up the part.

Some parts will be difficult to join as the wood doesn't want to bend in a nice curve. You will need to push back, out from the middle and from the top to press the tabs of the wall in to the notches. It will require a bit of force but be very careful so you don't break the wall.

If it is too difficult to insert the wall you can try sanding the corners of the tabs. This will make it a bit easier to press in. Make sure you also press from the middle out, to keep a nice circular shape.

The design needs to be done this way otherwise you won't get a nice rounded part once assembled. But this makes the assembly a bit more difficult. As mentioned, light sanding will help.

Once the wall is inserted, turn around the part and press on the bottom bracket. This will join the two pieces nicely.

The wall will hold together quite well at this point. This step is similar to the one above but a bit easier. Start pressing on the top bracket. Starting at the middle of the wall as before is probably the best option.

Go slow and press the top bracket on to the wall.

Once done turn the part around as before and firmly press on the bottom. This will align everything and press the parts together.

As before, if it is too difficult sanding the edges of those parts will make it easier to press together.

If you see the wall bulging out at the joint, you can add a bit of glue in to the joint and use string to hold it together. I used tape which also worked but I think wrapping some string around tightly would be the better option.

Set aside and wait for the glue to cure.

As an optional last step you can paint or stain the cup for a nicer look.