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Old Oct 10, 2011, 07:34 AM
Retardedly intelligent
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beavercreek,ohio
Joined Jan 2007
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Quote:
Originally Posted by leadfeather View Post
If you can control yaw with the motors in forward flight would you prefer no rudder/servo or would you prefer to keep the rudder?
probably keep the rudder, but its not a big deal. its just a bit of redundancy incase of a motor failure. Its one of the reasons why I cringe when I see the concept for the QTR. they'll most likely go into a flat spin if they have an engine failure. and that it looks a little retarded without a vertical stabilizer
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Old Oct 10, 2011, 07:47 AM
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Originally Posted by foam and tape View Post
probably keep the rudder, but its not a big deal. its just a bit of redundancy incase of a motor failure. Its one of the reasons why I cringe when I see the concept for the QTR. they'll most likely go into a flat spin if they have an engine failure. and that it looks a little retarded without a vertical stabilizer
So far, there are two versions that have been tested and proven in the F-35. Dual tilting front rotors and tail controlled yaw. Your Quad should be a fairly simple modification of the code...I think. Cass3825 is the man (genius) to do this. I'll help if I can.
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Old Oct 10, 2011, 11:42 AM
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Old Oct 10, 2011, 10:19 PM
Design, Build, and Fly
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Pleasant Grove, Utah
Joined Nov 2001
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Are you guys aware of UAV Forge? This would be a strong entry. I've been thinking of entering this, but like foam and tape, too much school in the way.

http://www.uavforge.net/
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Old Oct 11, 2011, 07:26 AM
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From post #1



Basically I have 3 flight modes:

1: hover (quad mode)
gyro gains active
flight controls active (or not) I really don't care
switch off

2:transition
gyro gains active for 5 seconds, it would be ideal for the values to be turned down to 0% in a slow motion function. After the gains are set to zero the motors only respond to ch3 or throttle
flight controls active
switch on

3: forward flight (airplane mode)
gyro gains off (motors only respond to throttle only)
flight controls active
switch on

4: transition back to HOV
gyro gains transition from 0% to 100% in a 5 second duration
flight controls active
switch off



In your flight mode 2, I would recommend leaving the gyros active. It doesn't cause any problems and... if you slow down; nose high; you can actually slow down to the point the control surfaces won't have enough air speed to control the plane and in this case the motors will keep the plane stable. The programming is simpler too without fading the gyros on and off.
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Old Oct 11, 2011, 12:46 PM
Retardedly intelligent
foam and tape's Avatar
beavercreek,ohio
Joined Jan 2007
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Quote:
Originally Posted by leadfeather View Post
From post #1



Basically I have 3 flight modes:

1: hover (quad mode)
gyro gains active
flight controls active (or not) I really don't care
switch off

2:transition
gyro gains active for 5 seconds, it would be ideal for the values to be turned down to 0% in a slow motion function. After the gains are set to zero the motors only respond to ch3 or throttle
flight controls active
switch on

3: forward flight (airplane mode)
gyro gains off (motors only respond to throttle only)
flight controls active
switch on

4: transition back to HOV
gyro gains transition from 0% to 100% in a 5 second duration
flight controls active
switch off



In your flight mode 2, I would recommend leaving the gyros active. It doesn't cause any problems and... if you slow down; nose high; you can actually slow down to the point the control surfaces won't have enough air speed to control the plane and in this case the motors will keep the plane stable. The programming is simpler too without fading the gyros on and off.
that could work, We can always try it I'm just not sure how badly its going to affect forward flight? maybe once the motors pass 45degrees the gyros can shut off as past 45 any movement from the quad mode seems to have ill effects on its flight performance.
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Old Oct 11, 2011, 08:25 PM
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Originally Posted by foam and tape View Post
that could work, We can always try it I'm just not sure how badly its going to affect forward flight? maybe once the motors pass 45degrees the gyros can shut off as past 45 any movement from the quad mode seems to have ill effects on its flight performance.
That's what we did for the F-35. In hover and fast hover (motors tilted about 45) gyros active on motors. Forward flight no gyros on motor.

I started calling it fast hover because calling it transition started to sound confusing...transitioning to transition.

In flight testing, anything much greater than 45 degrees of motor tilt and it starts to yaw with control inputs. 45 and less tilt on the motors and the craft rolls with control inputs.
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Old Oct 15, 2011, 09:47 PM
Retardedly intelligent
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beavercreek,ohio
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ok, round two this time I shortened the fuse a bit and moved the wings closer to try to get better flight performance as the last one had too much vertical area upfront.

hovering has exponentially gone up though, since its now setup as a slanted H copter with the bottoms wider than the front, the leverage of the motors has changed. this in turn has caused a bunch of problems as the board won't compensate for the different parameters.... I really don't know if this is solvable, maybe if the sensitivity of 11 and 9 could be turned down on Roll and Yaw it should fly fine. If not I guess i can live with it.
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Old Oct 15, 2011, 10:04 PM
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Joined Feb 2005
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The new PIDMIX in V1.8 and up makes is easy to tweak the sensitivity of the motors individually. We're finalizing the tweaks on the Tri now, and should have a quad model defined for you to test in the next few days. What pin are you using to tilt the motors?
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Old Oct 15, 2011, 10:09 PM
Retardedly intelligent
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beavercreek,ohio
Joined Jan 2007
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currently no pins, its straight off the RX. Thats great news to hear about the awesome code you're developing! I was starting to have second thoughts about this project/design. The final design will change though as this fuse doesn't match the wings.
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Old Oct 16, 2011, 02:18 PM
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There is now a VTOL_QUADX model defined in the code, which can be downloaded here. The sensitivity of motors 11 and 9 have been set at two thirds of the front motors to compensate for the longer arms in the rear. I'm curious to see how well this works! You will need a y-cable for the rudder still, as it is not defined separately in the code. I included yaw authority with throttle in forward flight, so you can test how it handles with and without the rudder servo. We've had good luck without a rudder servo on the F-35, hopefully you will experience the same. Download it, take a look around, and let me know if you have any questions. Good luck!

Billy

EDIT: Servo pins are:

Pin A0: left aileron servo
Pin A1: right aileron servo
Pin A3: motor tilt servo
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Old Oct 17, 2011, 03:34 AM
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Originally Posted by foam and tape View Post
ok, round two this time I shortened the fuse a bit and moved the wings closer to try to get better flight performance as the last one had too much vertical area upfront...
Looks good. This one should perform well.
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Old Oct 18, 2011, 08:02 PM
Retardedly intelligent
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beavercreek,ohio
Joined Jan 2007
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ok, I tried the code out and it seems to be working pretty good! I also removed all of the wing in the prop wash to improve power consumption as alot of power is wasted in hover. I also added the servos in and I cant get them to work? one of them is glitching pretty badly and the other one moved to its fullest position and is now frozen. Rudder works fine and what should I do now to get it to go into FF flight mode, the switch I want to use to transition is coupled to pin 7 on the arduino.
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Old Oct 18, 2011, 09:21 PM
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Originally Posted by foam and tape View Post
ok, I tried the code out and it seems to be working pretty good! I also removed all of the wing in the prop wash to improve power consumption as alot of power is wasted in hover. I also added the servos in and I cant get them to work? one of them is glitching pretty badly and the other one moved to its fullest position and is now frozen. Rudder works fine and what should I do now to get it to go into FF flight mode, the switch I want to use to transition is coupled to pin 7 on the arduino.
Which radio will you be using?

With the plane powered up and connected to the GUI, you will need (or should) set the travel on Throttle, Pitch, Roll and Yaw so that the graphics go from 1000 at the low end to 2000 at the high end +/-5. Make sure your props are off in case you accidentally arm the motors. During this step.

Your tilt channel will need to go from about 1250 to about 1750. The servo stretching distorts this . I think cass3825 may try to change this so that the settings are about 1000 to 2000 like the other channels. On my radio I start with the flap at 50% at both high and low ends and I trim a little from there.

Once you have this done see if the servos behave the same way and we can go from there.
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Old Oct 20, 2011, 01:40 PM
Retardedly intelligent
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beavercreek,ohio
Joined Jan 2007
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ok, I'll try this later today, i'm currently using the DX7. What kind of servos did you use Leadfeather on your F-35?
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