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Registered Member #816
Joined: Sun Jun 03 2007, 07:29PM
Location:
Posts: 156
That’ll be 2.5 minutes flying time then if you can use nearly all the batteries capacity, and about the same power as an average vacuum cleaner motor. Are you building a quad with some more of them? I take it this is for the flying robotic challenge, seen your other posts on it, lot of respect to you Patrick for taking on what is such an immensely difficult task.
Registered Member #2431
Joined: Tue Oct 13 2009, 09:47PM
Location: Chico, CA. USA
Posts: 5639
AndrewM wrote ...
The project is... purchasing a fan and ESC?
So mission accomplished then?
well, spending money, mission accomplished there too! it ran for 13:30 at 25% throttle, by calculation it should run for about 3 mins at 100% i think...
Electra wrote ...
That’ll be 2.5 minutes flying time then if you can use nearly all the batteries capacity, and about the same power as an average vacuum cleaner motor. Are you building a quad with some more of them? I take it this is for the flying robotic challenge, seen your other posts on it, lot of respect to you Patrick for taking on what is such an immensely difficult task.
I was planning on making a tri-copter, or maybe a bi-copter, but im still doing the math on the free body diagram. I wanted to use the above ducted fan, but its throttle response (spool-up time)is too slow for my PID/Kalman loops, so i think ill just use a 8 inch prop with a fiberglass/CF duct wrapped around it. Yes it is for IARC mission 6 this year, i got the flight club up and going on campus too, so ive been busy... i have calculus 121 class too.
Registered Member #65
Joined: Thu Feb 09 2006, 06:43AM
Location:
Posts: 1155
The KV of these ducted fans is usually double that of regular out-runners for a prop setup. These are great for small high velocity airplanes, but do not perform well for vectored thrust setups.
That battery's days are likely numbered if the ESC isn't setup to regulate the drivers.
Registered Member #2431
Joined: Tue Oct 13 2009, 09:47PM
Location: Chico, CA. USA
Posts: 5639
Carbon_Rod wrote ...
That battery's days are likely numbered if the ESC isn't setup to regulate the drivers.
Cheers,
It will cut out, yet keep the recieverand servos going, so the battery will be quite happy.
Anyway, im going over to a Power 10 E-Flight with a prop 10 x 3.8... that ducted fan just wont respond fast enough to be useful in this app, even at 40,000 rpm.
Registered Member #65
Joined: Thu Feb 09 2006, 06:43AM
Location:
Posts: 1155
Most EDF VTOL platforms have an inertia control lag issues:
A 4 cell pack tends to allow EDF units to actually reach the correct rpm for the turbine.
Have you considered a small variable pitch quadrotor with a low center of mass? You could try 4 large belt drive helicopter booms with tail rotors, and fast brush-less mini servos. That way the single engine rpm stays almost constant, and movement can be very rapid.
Registered Member #1643
Joined: Mon Aug 18 2008, 06:10PM
Location:
Posts: 1039
I know in battlefield 2, vertical take off jets had a turbine in the back...once in the air, it rotated 90 degrees, to turn into the main propulsion jet. Im sure one could do similar with a vtol, to move quicker :)
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69mm Electric Ducted Fan, 2.8 lbs Static Thrust...
