3 ms·

Great idea if you have robust controls! Terrible idea if you don't, because a crash can handily result in a fire or an explosion.

dredmorbius 7y ago
Heavier fuels (kerosen, a/k/a jet fuel, diesel) have equivalent energy density to petrol, but are far less flamable. You might get a small fire, but not an explosion. And there are a lot of RC aircraft already. They are noisy, however. Drone buzz now is simply from spinning fans. Adding a reciprocating motor to the mix is all the louder. The alternative is lighter airframes and solar power. For quads / octos, probably not viable, but for a prop-driven fixed-wing craft, a very small amount of thrust to counter gravity could be quite effective. Expanded polystyrene or similarly light body, solar cells over all horizontal surfaces, and an ultra-lightweighted controls and imaging payload. That would allow for long-duration flights at least in daylight. The low-energy use would also make battery-powered night flights more viable, certainly beyond 15 minutes. The principle cost is loss of hover capabilities.
- i_am_proteus 7y ago
  Yes, but the motor (turbine) to run kero is more expensive than the motor (piston) to run petrol.
  - grogenaut 7y ago
    The motor to run the drones was expensive till they became mass produced and dropped in price. Same for the batteries. DJI Drones aren't exactly cheap either. also I believe if you want to be pedantic, if it runs on combustion it's a engine. if electric then a motor.
    - eitland 7y ago
      > also I believe if you want to be pedantic, if it runs on combustion it's a engine. if electric then a motor. I think that might be less general than you think: General Motors hasn't exactly been known for their electric motors the last few decades. Also see: https://en.wikipedia.org/wiki/Engine https://en.wikipedia.org/wiki/Engine
      - twic 7y ago
        "Motor" is commonly used for rockets too, eg: https://en.wikipedia.org/wiki/Model_rocket_motor_classification#Motor_impulse_by_class https://en.wikipedia.org/wiki/Model_rocket_motor_classificat...
    - dredmorbius 7y ago
      The motor/engine dichotomy is blurry at best. However "reciprocating engine" has a clear usage preponderance over "reciprocating motor": https://books.google.com/ngrams/graph?content=reciprocating%20engine%2C%20reciprocating%20motor&year_start=1800&year_end=2000&corpus=15&smoothing=3&direct_url=t1%3B%2Creciprocating%20engine%3B%2Cc0%3B.t1%3B%2Creciprocating%20motor%3B%2Cc0 https://books.google.com/ngrams/graph?content=reciprocating%...

dredmorbius 7y ago

Heavier fuels (kerosen, a/k/a jet fuel, diesel) have equivalent energy density to petrol, but are far less flamable. You might get a small fire, but not an explosion. And there are a lot of RC aircraft already. They are noisy, however. Drone buzz now is simply from spinning fans. Adding a reciprocating motor to the mix is all the louder. The alternative is lighter airframes and solar power. For quads / octos, probably not viable, but for a prop-driven fixed-wing craft, a very small amount of thrust to counter gravity could be quite effective. Expanded polystyrene or similarly light body, solar cells over all horizontal surfaces, and an ultra-lightweighted controls and imaging payload. That would allow for long-duration flights at least in daylight. The low-energy use would also make battery-powered night flights more viable, certainly beyond 15 minutes. The principle cost is loss of hover capabilities.

i_am_proteus 7y ago
Yes, but the motor (turbine) to run kero is more expensive than the motor (piston) to run petrol.
- grogenaut 7y ago
  The motor to run the drones was expensive till they became mass produced and dropped in price. Same for the batteries. DJI Drones aren't exactly cheap either. also I believe if you want to be pedantic, if it runs on combustion it's a engine. if electric then a motor.
  - eitland 7y ago
    > also I believe if you want to be pedantic, if it runs on combustion it's a engine. if electric then a motor. I think that might be less general than you think: General Motors hasn't exactly been known for their electric motors the last few decades. Also see: https://en.wikipedia.org/wiki/Engine https://en.wikipedia.org/wiki/Engine
    - twic 7y ago
      "Motor" is commonly used for rockets too, eg: https://en.wikipedia.org/wiki/Model_rocket_motor_classification#Motor_impulse_by_class https://en.wikipedia.org/wiki/Model_rocket_motor_classificat...
  - dredmorbius 7y ago
    The motor/engine dichotomy is blurry at best. However "reciprocating engine" has a clear usage preponderance over "reciprocating motor": https://books.google.com/ngrams/graph?content=reciprocating%20engine%2C%20reciprocating%20motor&year_start=1800&year_end=2000&corpus=15&smoothing=3&direct_url=t1%3B%2Creciprocating%20engine%3B%2Cc0%3B.t1%3B%2Creciprocating%20motor%3B%2Cc0 https://books.google.com/ngrams/graph?content=reciprocating%...