10 ms·

Google has been experimenting with tailsitters, which I think is a no-brainer. Zipline is, imho, the real out of the box thinker. Catapault launch plus the sna

by kortex 7y ago

Google has been experimenting with tailsitters, which I think is a no-brainer. Zipline is, imho, the real out of the box thinker. Catapault launch plus the snag line is Short takeoff, effectively-vertical landing, main downside is you need ground gear to land without damage. Main upside is weight savings for peak power (takeoff) is reduced, landing gear gone, and your engineering space is shrunk to solely the problem of steady state flight. I foresee the paradigm of winged mothership for last-hundred-mile, plus n-rotor drones for air-to-land leg of delivery.

walrus01 7y ago
Zipline's system is a much lower cost, light weight implementation of what InSitu (now a Boeing subsidiary since they were acquired) designed for the defense market, for their Scaneagle. They were by no means the first to launch or recover a fixed wing drone in that manner. As you point out it provides a lot of advantages in not needing to carry the extra weight for a VTOL, no landing gear, extra energy boost on launch. It's very close to the optimal energy usage in watts for motor, per size of craft, that can be achieved right now. The other advantage of using a single motor fixed wing craft is ability to use lithium ion batteries which are relatively higher Wh/kg density. These are not as capable of instantaneous high amps as lithium polymer are. The best commodity, commercially available lithium ion batteries are in the range of 210 to 248Wh/kg right now. The best lithium polymer batteries are about 178Wh/kg. FPV hobbyist fliers who build fixed wing and flying-wing craft use lithium ion for longer range. https://www.google.com/search?q=insitu+scaneagle&client=ubuntu&hs=uvY&channel=fs&source=lnms&tbm=isch&sa=X&ved=0ahUKEwizuM3nqu3jAhVLrZ4KHZQVDnoQ_AUIESgB&biw=1329&bih=1011 https://www.google.com/search?q=insitu+scaneagle&client=ubun...
wereHamster 7y ago
Zipline only works if you have a single base where you launch from land at. If you need to land at the customers site then you need VTOL capability.
- joncrane 7y ago
  I think the idea is that the full-payload drone is launched via catapult, and the takeoff from the customer's site is without payload, allowing for lower power.
jcims 7y ago
Yeah I've been thinking same, possibly a UAV dirigible for the mothership. That would be cool.

by kortex 7y ago

walrus01 7y ago

Zipline's system is a much lower cost, light weight implementation of what InSitu (now a Boeing subsidiary since they were acquired) designed for the defense market, for their Scaneagle. They were by no means the first to launch or recover a fixed wing drone in that manner. As you point out it provides a lot of advantages in not needing to carry the extra weight for a VTOL, no landing gear, extra energy boost on launch. It's very close to the optimal energy usage in watts for motor, per size of craft, that can be achieved right now. The other advantage of using a single motor fixed wing craft is ability to use lithium ion batteries which are relatively higher Wh/kg density. These are not as capable of instantaneous high amps as lithium polymer are. The best commodity, commercially available lithium ion batteries are in the range of 210 to 248Wh/kg right now. The best lithium polymer batteries are about 178Wh/kg. FPV hobbyist fliers who build fixed wing and flying-wing craft use lithium ion for longer range. https://www.google.com/search?q=insitu+scaneagle&client=ubuntu&hs=uvY&channel=fs&source=lnms&tbm=isch&sa=X&ved=0ahUKEwizuM3nqu3jAhVLrZ4KHZQVDnoQ_AUIESgB&biw=1329&bih=1011 https://www.google.com/search?q=insitu+scaneagle&client=ubun...

wereHamster 7y ago

Zipline only works if you have a single base where you launch from land at. If you need to land at the customers site then you need VTOL capability.

joncrane 7y ago
I think the idea is that the full-payload drone is launched via catapult, and the takeoff from the customer's site is without payload, allowing for lower power.

jcims 7y ago

Yeah I've been thinking same, possibly a UAV dirigible for the mothership. That would be cool.