Mark I Results

The measurements are satisfactory but not great, so I've moved on to the Mark II design. It achieved 1.7 m/s using just the first coil. Image the projectile going about four feet, when fired from a tabletop about four feet high.

Connecting the next two coils did not help -- sometimes it would shoot faster, but usually they would slow or even stop the projectile. It is very unreliable. If the results were consistent then timing could be adjusted for better performance, but it's frustrating to work on something that behaves differently with every shot.

I think the problem lies in the open-loop design. Each coil really needs to be energized exactly when the projectile reaches a certain position. Using a fixed timing method just isn't adequate because it doesn't adjust for small changes in each firing.

Also this design is too complicated to build and debug.

So... the Mark II design will simplify things as much as possible! Just keep reading...