Collective jumping
« on: March 18, 2018, 06:01:07 pm »
I have set up the heli, ever thing seems to be working properly,except...
When i move the collective it moves up to mid stick, then jumps to the bottom and starts moving up again. It is really weird. Throttle is on 6 pitch is on 2.
(link fixed by TheOtherCliff)
Video link.   

Does anyone have any ideas?

Thanks Brad
« Last Edit: March 18, 2018, 06:37:17 pm by TheOtherCliff »

Re: Collective jumping
« Reply #1 on: March 18, 2018, 06:33:43 pm »
Looks like it stripped the video link.



Thanks

Re: Collective jumping
« Reply #2 on: March 18, 2018, 06:35:18 pm »
I can imagine that happening if you have "idle up" function enabled on your transmitter.

LP assumes you are using a simple transmitter type without using a throttle or collective curve.

Look at GCS Input->RCInput page while you are doing this.  Does the collective channel move like you describe?  If so, your transmitter is actually sending that.

(you must use youtube.com, not e.g. youtu.be etc.)

Also, if using PPM, you must be careful to keep pulse widths from being too long and not to use more than 9 channels with PPM.  Individual control channel width should be 100%, not e.g. 140%.  It can be that it jumps to the next channel so that for instance your collective is sometimes actually connected to the yaw (or other) control.

I have a mismatched set of transmitter brand and receiver brand where it gets full left rudder when I give full throttle, but works fine at 85% throttle.
« Last Edit: March 18, 2018, 06:45:24 pm by TheOtherCliff »

mr_w

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Re: Collective jumping
« Reply #3 on: March 18, 2018, 07:56:46 pm »
Actually had same problem, and solved it by making curve2 (which I assume is collective curve) be V shaped instead of lienar / see here https://forum.librepilot.org/index.php?topic=4190.msg28466#msg28466

This I have figured  out by observing the channel values and movement. Not sure about the magic involved, but somehow the mixer that handles collective does not like the the rc channel value going from -1 to +1.

I suppose this could be solved with TX side curves too.

I should also mention I have "collective passthrough" option enabled.
« Last Edit: March 19, 2018, 12:42:20 pm by mr_w »

Re: Collective jumping
« Reply #4 on: March 18, 2018, 09:40:09 pm »
I am using SBUS and the the the collective and throttle curve are a straight linear progression, no fancy curves. Should i let the CC3D handle all the curves? I have the option to change to PPM would that be better for the controller?

Checked the radio output and it seems it it is sending the proper outputs.

Thanks, for the quick response. I really want to get this working on this little 180cfx.

Thanks,
Brad

utoedter

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Re: Collective jumping
« Reply #5 on: March 18, 2018, 09:54:09 pm »
I have set up the heli, ever thing seems to be working properly,except...
When i move the collective it moves up to mid stick, then jumps to the bottom and starts moving up again. It is really weird. Throttle is on 6 pitch is on 2.
(link fixed by TheOtherCliff)
Video link.   

Does anyone have any ideas?

Thanks Brad

Hi Brad,

Did you set the center value of the collective channel near to minimum? Thats mandantory, if you do not, the swash plate usually jumps. And i recommend to set the swash plate travel during the swash plate adjust procedure from -20 degree to + 20 degree.  if you dont do, you will not have enough travel, because all values are mixed together with a 50% factor. And no curve on the remote, as cliff said.

Udo

Re: Collective jumping
« Reply #6 on: March 18, 2018, 10:49:22 pm »
I set the collective through the process but it never recenters after the min step? Not sure what is going on with this thing?

Re: Collective jumping
« Reply #7 on: March 18, 2018, 10:53:43 pm »
Seems to be having an issue around mid stick. ONLY on this heli. Mid stick is working fine on every other heli i have with no glitches.

karla

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Re: Collective jumping
« Reply #8 on: March 19, 2018, 01:43:16 am »
I set the collective through the process but it never recenters after the min step? Not sure what is going on with this thing?

Can you upload your uav file here?

Re: Collective jumping
« Reply #9 on: March 19, 2018, 01:48:54 am »
Looks like it is already attached to first post.  :)

karla

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Re: Collective jumping
« Reply #10 on: March 19, 2018, 01:54:52 am »
 :)

karla

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Re: Collective jumping
« Reply #11 on: March 19, 2018, 03:19:13 am »
@attituderc,

Try this
. in GCS, Config, Remote control, on the settings for Collective: set the Neutral value to 205 (or just slightly higher than your Min value of 205, like 207).
. in Vehicle, Helicopter, Basic settings, CCPM options, un-check the Link Roll/Pitch option.

... thats basically what Udo said previously.

Re: Collective jumping
« Reply #12 on: March 19, 2018, 09:55:40 am »
Here is what I have tried.
Switched to PPM (thinking SBUS was an issue) No help but had to reset all the values.
The Min is 1000 max is 2020 with PPM
Set the neutral on the collective to 1002 (as described, no change)
Unchecked link picth and roll. (no change)

The collective climbs to mid stick then resets to the bottom and starts moving again. No curves set up in the radio. Could it be software version?

Thanks for your help,

Brad

Re: Collective jumping
« Reply #13 on: March 19, 2018, 10:02:01 am »
new uav file


karla

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Re: Collective jumping
« Reply #14 on: March 19, 2018, 10:37:38 am »
What I see is in your file
. the Collective Neutral is still way too large (1509, and min is set to 994, put the Neutral to 994 or 996)
. the Link Roll/Pitch is still checked.

Please chek it?
« Last Edit: March 19, 2018, 11:13:49 am by karla »