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For much more detail on the design I recommend the Draft FAI World Record Claim they are submitting. (https://dl.dropboxusercontent.com/u/5093348/Draft%20Atlas%20...)

Interesting tidbit:

"The pedaling of the pilot pulls on and reels in four Vectran cords, which are pre-spooled onto each of the four rotor hubs. The action of unspooling the cord and pulling on the rotor hub drives each rotor to overcome the drag force."



Thanks for the link! Lots of interesting info:

Empty Weight: 55.1 kg All-Up Weight: 130.1 kg Flight Power (0.5 m): 450 W Flight Power (3 m): 750 W

I wonder if those wattage numbers are estimates or measurements.


Replying to self, as I just noticed (awesome!) they included a power chart for the record flight.

About 1kw for the first 12 secs, then settling down to 600w for most of remainder. That's a boss ride, especially for a 70kg rider. Dude's a monster.


That's very impressive.

To put that into perspective, that's a chart[1] that some exercise scientists have put together that shows what power cyclists of varying levels tend to be able to produce. The data in the spreadsheet gives an average power of 708W for a minute, which equates to 10.1W/kg at 70kg, which puts him at the level of a category 1 racer or domestic pro.

Keep in mind that the ~1000W spike for 10s at the start of the ride probably harms the overall average, as a more constant power output generally leads to a higher overall average (or, higher power outputs are disproportionally harder).

Edit: according to the photo gallery in the article, Reichert is a nationally ranked speed skater in Canada, which is another one of the "big quads" sports.

1. https://s3.amazonaws.com/cyclinganalytics/static/cycling-pow...


I think that he had to spike at the beginning to get up to the 3m mark and then could "coast" at the lower value to stay level.

Edit: spelling


Yes, there's a chart that shows power and height vs. time, and it certainly looks like that was the case. I bet it didn't feel like coasting though :-)


And he's an engineer, to boot.


To put this in perspective, a fairly typical 1.6kg hexrotor with NO payload will pull around 200W of electrical power in hover[1].

These guys are lifting 130kg with ~750W...

[1]: 6.6Ahr battery @ ~14.4V, 95Whr of power. It'll go through that in slightly under half an hour, so it's pulling ~200W in hover. Small scale multirotors aren't very efficient. http://www.mikrokopter.de/ucwiki/FlugZeit#MikroKopter_als_He...


thanks for the link - I saw the big spools in the video and was trying to figure out what was going on. I presume that means that flight time is limited by cord length (rather than having a circulating loop like a bike chain)?


It would be interesting if they could get a version with six blades where (3) are required to provide lift and it oscillates between spooling/unspooling three of the six at a time such that you fly with 3 whilst spooling the other three - then "shift" between spools.


I like it: a 'pull-only' transmission system to take advantage of the tensile strength of lightweight materials.




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