Solution for Peter Knoppers' Eighteen Eights puzzle

These images depict the assembly process of Peter Knoppers' Eighteen Eights puzzle. This puzzle has six solutions that are very similar.

The pieces

There are two different kinds of pieces used in Eighteen Eights;
10 copies of the figure 8 piece (shown in green).
8 copies of the figure 3 piece (figure 8 with two units removed) (shown in red).

The assembly process

(Images created with POV-Ray by Peter Knoppers.)
Take six figure 8 pieces and two figure 3 pieces:

Insert each piece of type 3 into three pieces of type 8 (but leave them one unit away from the center):

Build a sub-assembly consisting of two pieces of type 3 and one piece of type 8:

Slide the new sub-assembly over the four outermost figure 8 pieces of the assembly that you built before.

Slide two pieces of type 3 one unit in to lock the sub-assembly in place:

Get two more pieces of type 8:

Slide each one over the outermost, standing pieces of type 8:

Get two more pieces of type 3:

Slide them into the top holes of the standing figure 8 pieces (but not quite to the center):

Use the remaining pieces to make another sub-assembly like before:

Slide the sub-assembly over the outermost standing pieces of type 8:

Lock the sub-assembly in place by sliding the figure 3 pieces in:

That's it.

The result

How to take it apart

It can be a little bit difficult to find the first move. You'll have to identify a pair of type 3 pieces with the gaps facing outward that can slide in the same direction. These must be moved one unit (not two) to unlock a sub-assembly.