Sparking gimmick
From MediaWiki
Some Transformers toys such as the Sparkabots and Firecons have had the ability to produce showers of sparks, simulating weapons or hot exhaust.
These sparks are produced by a mechanism that, when activated, allows a spinning steel wheel to rub against a flint, similar to that contained in a cigarette lighter.
Sparking mechanisms are notorious for wearing out after prolonged play, and for littering a toy's surface with burned-in crunchy bits, giving the spark-exit area a black-peppered appearance.
Though this gimmick is cool and fun, it isn't one that Hasbro considers any more for use in toys, probably for safety reasons.
