[SOLVED]CC3D throttle problem way too high to start with
« on: April 08, 2018, 08:39:12 pm »
Hello,

I am new to CC3D and I have setup the CC3D on my quadcopter. But there is some problem with the throttle.The motors dont slowly and gradually start from min and go linearly to maximum though the it is set to default linear throttle curve. But when I use the output tab in GCS and set the neutral points then the throttle works gradually increasing with the sliders in the output tab(all set to neutral at 1082). Also in the input tab the throttle value are set such that the minimum is at 1000 and max to 2000 and neutral at 1400. So instead of starting at 30% throttle or 40% throttle how do I make my transmitter stick gradually increase throttle. Also what I tried is setting the TxPID tab in GCS with throttle range minimum at 0.01 and max at 0.2. I dont know if it would work. Could some one please tell me how to solve this throttle problem?

Update:
More specifically channel 3 and 1 on the libre pilot have the motors starting at may be 70% of throttle. I disconnected all the ESCs and took one ESC with motor and tried 1-4 output channels on the CC3D board. 2 and 4 start gradually but 1 and 3 start at 70 of motor speed. So how do I also getting gradual throttle /speed of the motor on channles 1 and 3. Or since the quad is in acrobat mode these start at high throttle? I think there is no barometer sensor on the CC3D such that after the quad takes off the throttle gets adjusted automatically with height...Please let me know.
« Last Edit: April 12, 2018, 05:41:02 am by youthreewire »

Re: CC3D throttle problem way too high to start with
« Reply #1 on: April 08, 2018, 09:17:04 pm »
Be aware that when you move the transmitter stick just a tiny little above bottom, the outputs instantly go from min to neutral.  For thrust, your neutral should be much lower, very close to min, but up enough for the motors to all be running slowly.  Set your Input Thrust neutral to be say 80 above min before you do anything else.  So if min is 1000 then neutral should be about 1080.

There are several things, that can cause what you describe.  If you follow these instructions, the throttle stick should work correctly:
https://librepilot.atlassian.net/wiki/spaces/LPDOC/pages/12058743/ESC+Calibration

On a quad, any time you have motors that are diagonally installed that go very high, that is a sign that the quad is trying to rotate in the yaw (spin like a top) direction.  There are some different possible causes.  Is your yaw trim where you had it when you did transmitter wizard?
« Last Edit: April 08, 2018, 09:23:51 pm by TheOtherCliff »

Re: CC3D throttle problem way too high to start with
« Reply #2 on: April 09, 2018, 06:49:32 am »
There is a problem with the transmitter wizard. There is one step in the wizard which says move the Tx stick to their limits, when I do this I do not see the animated motion of the transmitter sticks. And also in the last step it asks are your Tx sticks in the matching position showed in the picture.Even then the animated sticks do not move but the when I check the input tab the limits are properly set and even the neutral positions. I also did manual calibration where the min max values are fine.

I am attaching a picture of the input tab and things look fine there I guess.Also the ESCs are calibrated fin because when I plug the same ESC into a channel which is behaving normally then the motor speed is normal. Only the diagonal motors are starting to spin at 70-80% of throttle. Some time what I observed is that even if they start slow their speed automatically increases. What shall I do now?
« Last Edit: April 09, 2018, 07:02:49 am by youthreewire »

Re: CC3D throttle problem way too high to start with
« Reply #3 on: April 09, 2018, 07:08:24 am »
As I recall, there is a problem with the visualization of the transmitter in the GCS wizard if you don't have a flight mode switch.

The problem is only the visualization.  The actual calibration works.  If you make carefully sure that you move each control to it's limits and pretend that the visualization is working, it actually works.

@f5soh knows more about this, but I believe that this is an accurate description.

The slow windup is normal.  It is trying harder and harder to be level, but it doesn't move because it is solidly on the ground.  If it were free to move freely in the air, it would move a little with the small amount of motor difference, and the motors would stop increasing.  So ignore this effect.

Re: CC3D throttle problem way too high to start with
« Reply #4 on: April 09, 2018, 08:08:02 am »
Ok I will try to fly it and see...

Re: CC3D throttle problem way too high to start with
« Reply #5 on: April 10, 2018, 08:05:37 am »
I ran two test flights. In both test flights the drone starts tipping. There may not be much yaw but the drone tips to one side. I thought the CC3D flight controller would stabilize it and maintain level flight. So what is going wrong..could you please see that attached video and tell me..

(theothercliff fixed video link to be youtube.com instead of youtu.be)
« Last Edit: April 10, 2018, 10:25:28 am by TheOtherCliff »

Re: CC3D throttle problem way too high to start with
« Reply #6 on: April 10, 2018, 06:33:02 pm »
Great setup for testing without breaking it!

Have a look at this post:
https://forum.librepilot.org/index.php?topic=4236.msg28758#msg28758

Re: CC3D throttle problem way too high to start with
« Reply #7 on: April 10, 2018, 06:51:34 pm »
I am not confident about the connections to the motors are in right order. The CC3D I purchased is a black board with yellowish translucent case.I have not mounted the motors in the order shown in the wizard because I checked each motor would speed up or slow down in the right way when I tilt the UAV platform either to left or right. I followed the description about setup here.
https://www.dronetrest.com/t/cc3d-flight-controller-guide/830

My CC3D does not have the same color of wires for the input channels of yaw ,pitch and roll as shown in the above link.  My colors of the wire are starting with the 3 pin connector white,brown,orange.red,white and yellow. Now my transmitter is set to mode 2 throttle on left. Earlier when I connected the motors and the input channels on the CC3D as per the order shown in the page my craft would tip over. Right now it is not tipping that badly. Could some one give me a reliable connection diagram for this CC3D's colored wires....

@Cliff..hey thanks I just got some bricks and tied plastic ropes and the first time they a little loose and the drone tipped. So now I have them a tighter. Also on my CC3D case the arrow is on the front and the ESC connector pins are on the back (arrow in north side and ESC pins on the south side).
« Last Edit: April 10, 2018, 06:57:28 pm by youthreewire »

Re: CC3D throttle problem way too high to start with
« Reply #8 on: April 10, 2018, 07:21:44 pm »
I did some changes as per the instructions here
http://opwiki.readthedocs.io/en/latest/user_manual/cc3d/cc3d.html#coptercontrol3d-cc3d-and-atom-and-coptercontrol-introduction

I will test this tomorrow morning and let you know.
« Last Edit: April 10, 2018, 07:26:26 pm by f5soh »

Re: CC3D throttle problem way too high to start with
« Reply #9 on: April 10, 2018, 07:27:49 pm »
The following assumes a normal full sized CC3D with yellow case.  I have one.

There are configuration settings to change these things, but the easy thing to do is:
- FC must be mounted with arrows forward and ESC connectors on top right side (or search "rotate virtual" in wiki)
- ESC connector numbering is critical, #1 is in front, etc.
- You MUST follow the GCS motor numbering on the Vehicle page
- Motor spin direction / prop type is critical for a quad, two wrongs do not make a right
- Motor spin direction is not so critical for a tricopter, but can cause extra trim offset for the tail motor (and other small issues)

Re: CC3D throttle problem way too high to start with
« Reply #10 on: April 10, 2018, 07:32:43 pm »
Here is the arrow on the case and inside the PCB also the arrow points towards receiver port on the CC3D as front. Picture attached. This CC3D is differently marked interms of the arrow.So I have assumed that as front and made fresh connections now. I maintained the same order of pitch,yaw and roll irrespective of color on the receiver port. Let me see if this works now.

f5soh

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Re: CC3D throttle problem way too high to start with
« Reply #11 on: April 10, 2018, 07:35:00 pm »
If you mount the board with a custom orientation, you need to adjust the Virtual Attitude Rotation in Configuration Attitude tab.
Right orientation is printed on board, this case looks wrong.
Take a look here
A quick check can be done using the PFD in flight data tab.

Please note all the config panels are documented into the Wiki, you just need to click into the small blue "?" icon.

Re: CC3D throttle problem way too high to start with
« Reply #12 on: April 10, 2018, 08:45:45 pm »
Even the blsck PCB has the arrow in the same direction as the case .

f5soh

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Re: CC3D throttle problem way too high to start with
« Reply #13 on: April 10, 2018, 09:01:59 pm »
Looks like this is a new CC3D version :)
Check the orientation using the PFD (look video linked above), just to be sure.

Re: CC3D throttle problem way too high to start with
« Reply #14 on: April 11, 2018, 07:38:31 am »
As per the new orientation,I connected the motors and now I tested each of the motors individually and they are appropriately speeding up and slowing down as per the tilt of the quadcopter. But two motors are initially starting at very high speed (motors 3 and 4 as per the wizard's connection) but when I tilt the frame around the motors then get adjusted. If these motors do not start with high starting RPM then I am set. I will do a test flight this evening and let you guys know.