Some recently-discovered c/4 diagonal spaceships include accessible sparks, which can be used to make alterations to other active or stable patterns
in passing. Recent discoveries include alterations that reflect gliders 180 degrees, or convert a single glider into multiple gliders — along with
a c/4 wickstretcher with a wick that can be ignited by gliders, where the resulting fuse can be timed to burn out without harming the wickstretcher engine.
David Bell has used these results to complete an adjustable clean c/4 rake, with periods of the form 4508+32N. Bell's description follows:
The rake has an engine convoy at the front, two convoys forming lines behind
that, and a V-shaped convoy at the back. The recipe to create the next rake
in the series is:
Move the top line convoy orthogonally right by 6 cells.
Move the left line convoy orthogonally down by 6 cells.
Move the V-shaped convoy diagonally back by 6 cells.
This will increase the period by 32 generations.
The modifications can be be made in the opposite direction to form the
earlier rakes in the series. Moving the convoys by 300 cells creates the
first rake in the series, having the period 4508.