- either lightning strike- using a renderable spline that glows and jiggles about,
- or Particle-flow that emits long cylinders lke sparks which are attracted to the bunsen.
The second seems the most promising, both are quite a bit of setting up to render a scene of only about 4 seconds. Partcle flow is the most entertaining to use, it makes you think in a logical way rather than a visual one.
cycling: finally got those wretched gears working properly. The gear change is now quite good, earnly up to Campagnolo standards.