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Mar 05, 2013, 03:12 PM
Registered User
Discussion

what happens if you change rotation direction of the props midflight? [fp 3D quad]


this!

mwc quad // ultraesc 3d (2 min 53 sec)


my first cautious attempts to fly a 3d capable quad


experimental ultraesc fw.
modded mwc fw [oneshot + 3d] for nanowii board.
modded 8x4.5" cf reinforced props.

ultraesc setup:
- input pwm 125-250Ás oneshot
- motor pwm 32khz
- active freewheeling enabled [synchronous rectification]

more info https://www.rcgroups.com/forums/show....php?t=1799000
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Mar 05, 2013, 03:14 PM
Mmmmmmm!
WiseDuck's Avatar
Alright, that is cool.

I want ALL the info needed to make this work!
Mar 05, 2013, 03:16 PM
Need more props..........
Oso Grande's Avatar
Wow
Mar 05, 2013, 03:21 PM
Don't panic!
Just a thought - as it is being widely considered, quad it doomed once 1 motor is out.

With reversing motors, could the quad land more safely with opposite motor able to reverse to compensate failed side going down?
Considering the fact that even 2 motors combined have enough power to at least decrease negative vertical speed?

By the way, are there any copters with variable pitch rotors?
Mar 05, 2013, 03:35 PM
Out of helis, sanity returning
Bravo! Beautiful innovation.
Mar 05, 2013, 03:36 PM
Head full of foam
OK, stupid operational question:

Does the FC do that automatically? As in, you get it upside down, the FC senses it's new attitude and it turns the props backwards to hover upside down. Or is this something you have to do on the remote, like flip a switch?
Mar 05, 2013, 03:37 PM
Don't panic!
Quote:
Originally Posted by RuralFPV View Post
OK, stupid operational question:

Does the FC do that automatically? As in, you get it upside down, the FC senses it's new attitude and it turns the props backwards to hover upside down. Or is this something you have to do on the remote, like flip a switch?
Or you throttle stick has zero in the center, not at the bottom?
Mar 05, 2013, 03:42 PM
Since 1902. Maybe.
Olivier_C's Avatar
I guess the throttle stick is simply set with zero at THR 50%, same as you would control the ESC for a buggy....
With maybe a little bit of dual-rate for the "reverse", since the props won't be as efficient.
Mar 05, 2013, 03:50 PM
Registered User
Quote:
Originally Posted by RuralFPV View Post
OK, stupid operational question:

Does the FC do that automatically? As in, you get it upside down, the FC senses it's new attitude and it turns the props backwards to hover upside down. Or is this something you have to do on the remote, like flip a switch?
v

Quote:
Originally Posted by vadimus View Post
Or you throttle stick has zero in the center, not at the bottom?
exactly.
throttle stick above center = normal rotation.
throttle stick below center = reversed rotation.
throttle stick at center = very slow normal rotation.
theres no position of the stick were the motors are stopped.

there is nothing else. its like controlling a normal cp heli.
Mar 05, 2013, 04:13 PM
Blacked out 350z - Texas
Wrice4's Avatar
Quote:
Originally Posted by warthox View Post
v



exactly.
throttle stick above center = normal rotation.
throttle stick below center = reversed rotation.
throttle stick at center = very slow normal rotation.
theres no position of the stick were the motors are stopped.

there is nothing else. its like controlling a normal cp heli.
You sir.......ROCK.
Mar 05, 2013, 04:41 PM
serial scratchbuilder
Granted's Avatar
I see a new breed of props in our future.
Mar 05, 2013, 05:18 PM
Registered User
Totally awesome ! ! !
Mar 05, 2013, 05:21 PM
Registered User
brilliant!
Mar 05, 2013, 05:21 PM
Suspended Account
Wow, this is a game changer,awesome work.
Mar 05, 2013, 05:43 PM
hacker
Hello!

I tried to do this early last year, since I added support for this in my tree since Nov 3, 2011, but found that most slow flyer props really suck at reverse thrust (pun not intended). I ordered some non-scooped props from Fancy Foam Models, as I recall, but never ended up getting them, and then forgot to try again. If flat is not available, higher pitch props probably work better. The ones warthox is using there seem to work but don't sound very happy.

For doing this with my code, you just need to set RC_PULS_REVERSE to 1 (which enables RC Car type mode) and perhaps adjust the endpoints, or calibrate them like with an RC car ESC. It will work on any board including without complementary PWM, though complementary PWM does actually help a bit with back-EMF detection and could probably flip directions a bit faster. This eventually led to the start-up improvements and ZC filtering in 2011/2012 that made higher inductance and pancake motors work better and not get stuck spinning the wrong way. I tested with a 2213N with no prop and could flip from full throttle one way to the other in <100ms with COMP_PWM=0.


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