This hot air machine is some form of hybrid steam - sterling engine, it has elements from both.
The main difference to anything else is that the hot air is only used to work/operating/controlling the pendulum.
The bottom of the double pendulum is doing the work.
As the pendulum is free swinging not constraint in any way the only loses are:
• Air resistance
• Friction
• Less than 100% perfect timing
• Movement for work to be done and angle of secondary leg.
Air resistance, not much of a worry moving at 10 km/h or Mph
Friction not much to be done about it, keeping it oiled.
A good way for timing the "strike" to be found over time.
Length of power stoke can be reduced with gearing from the top of the second arm. A 1 cm power stroke is of little use but with a 5:1 ratio that is something to work with. So bottom of second leg only needs to move less than ½ inch, with a 1 meter long pendulum the resulting angle is also only small loss.
Diaphragm configuration was original used because it like them but a small piston of 0.25 inch (6.35 mm) or thereabouts is a better choice as I see it now.
A 10 kg bob with a 1 meter pendulum having a 1 cm long power stroke every second is the aim for at start but there is a lot of things on the to do list as all piled up with this covid junk.
The system has 98 Joule (watt) of energy swinging full 180° (90° angle) 8 tea candles @30 watt is 240x0.4= 96 anything less than 8 tea candles is a win.
I am not aiming for efficacy improvements in fractions of a percent but in significant magnitude.
BTW
The wind turbine design now finished.
https://bitcoinfiles.org/t/a66f9d5c6d63 ... 64a90340f2