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Registered Member #2431
Joined: Tue Oct 13 2009, 09:47PM
Location: Chico, CA. USA
Posts: 5639
Chris Cristini wrote ...
Nice hope you upload a video Mosfet as a switch to cut off battery power simple but clever.
Yeah at the academic competition I attend every year, we need a absolute kill capability, and when I noticed a code bug I knew it needed to be a off-microcontroller operating solution. I can't have my machine going Cylon and chasing people down.
Registered Member #2431
Joined: Tue Oct 13 2009, 09:47PM
Location: Chico, CA. USA
Posts: 5639
It flies!!!
pic tricopter as flown in video.
its a bit wobbly due to the PID defaults, and the tail yaw not being free until it clears the ground. But all that will be fixed shortly. I have class and work so cant do much today, but I will post you tube video soon.
I need a child's pool noodle flotation thing for landing skids.
Registered Member #2431
Joined: Tue Oct 13 2009, 09:47PM
Location: Chico, CA. USA
Posts: 5639
BigBad wrote ...
nice....
Yep, I'm real happy. Now I just need to get the STM32F4 to be a good pilot for the autonomous features.
Also, having been given a lot to think about, I still want to Include efficiency gains we've talked about, but I also want to investigate fuel cells. The lipos batteries as good as they are, are the limiting factor to duration, lift, and distance capable of being flown.
Registered Member #2431
Joined: Tue Oct 13 2009, 09:47PM
Location: Chico, CA. USA
Posts: 5639
Ash Small wrote ...
Patrick wrote ...
I also want to investigate fuel cells.
Are fuel cells really going to have a power to weight advantage over LiPo's?
I imagine you'd have to scale things up quite a bit before fuel cells demonstrate any real advantages, but I'm only guessing here.
Nice work, by the way.
but it's either fuel cells or a tiny piston and generator onboard... We need 45 to 90 minute flight times. 5 to 8 minutes just isn't practical for police or forest fire fighters.
Registered Member #2529
Joined: Thu Dec 10 2009, 02:43AM
Location:
Posts: 600
If you really want long hang time you need excellent aerodynamics.
You might be ultimately better off with boomerang type vehicles; just one big spinning wing, with no fixed body at all. Sort of like a glider wing, but spinning. Maybe a low speed ducted fan to push the whole thing around.
Registered Member #3414
Joined: Sun Nov 14 2010, 05:05PM
Location: UK
Posts: 4245
BigBad wrote ...
If you really want long hang time you need excellent aerodynamics.
You might be ultimately better off with boomerang type vehicles; just one big spinning wing, with no fixed body at all. Sort of like a glider wing, but spinning. Maybe a low speed ducted fan to push the whole thing around.
Or just a powered glider.
You need really excellent L/D ratios.
Now you're talking. A VTOL 'glider' could have a lot of potential (but not for Patrick's competition). Use the motors for take0off and landing, and maybe for some propulsion in 'glider mode', and just glide and use thermals as much as possible.
It wouldn't take a lot of expanded polystyrene/balsa wood/ carbon to modify Patrick's design to glide as well.
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Electric Motor Effciency (Density / Watt / Losses)
Mosfet as a switch to cut off battery power simple but clever.
