Perler bead board
Update 19th Sept - Learned how to make this use the customiser! Now you can decide the size of board and spacing of pins within thingiverse.... yay thingiverse!
Update - 18th Sept - My daughter tells me that the pins are fractionally too close together - the beads fit on, but are very hard to take off. If you are using the SCAD file you might want to tweak min_gap up a fraction. Let me know in the comments if you try!
Circular pin board for Perler beads (or similar).
circles.stl is a small test board (to see if the beads fit)
circles6.stl is a bigger one (6 concentric circles)
circles.scad lets you make your own :)