so a while ago I made a prototype of an rc cannon thingymajig. the idea was to make two and have all functions (fire swivel and tilt) controlled remotely. I would then set them up on opposite ends of the lounge room and line minifigs up next to both. my son and I would then proceed to blast away. sadly, as is always the case, I never made a final model. I did put a short video up on youtube but I guess it was a squeak amongst the roars as it did not receive many views.
. I picked up one of those speed computers a few years ago when I was mad about making gearboxes... it does not count high enough to show speed of final axles (with the firing wheels) but from placing it somewhere else in the drive train they are going well over 4k rpm. ****sorry for long block of text, for some reason "enter" does not start new line**** the loss in power from first to 15th shot is noticeable, over 1krpm at wheels but it was still good enough to clear the width of my (small) house.