Two Gas Engines
Today I finished assembling the main helicopter structure and performed the break-in procedure for the second gas engine. The two gas engines are located near the center of the helicopter, so that if one stops running, the other can bring it down for a controlled landing.
On Friday, if I can successfully rent a helium tank, I may try doing a test flight. (The design still uses four helium-filled weather balloons.)
I'm increasingly concerned about the vibration of the gas engines, so I'm going to continue working on building an electric version of the helicopter.
One issue is with having both gas and electric helicopters is that different cameras would be suitable for the different versions. The electric one needs a very light camera, whereas the gas one can lift a heavier (higher-quality) camera.