Hello all,

I need some help with a revolution problem I am having:

No alarms in GCS, all setups went fine.  calibrated and calibrated esc's again to make sure.

When I arm the board, I apply a very slight amount of throttle to get the motors going and all the motors go to near max kv with that tiny bit of throttle.

Again, all systems seem go

The quad is an flame wheel type with built in pc board from HobbyKing
- ESC's are HobbyKing Blue Series 30A stock (are they BLHeli, One Shot or what? I don't know)
- Motors are Exceed RC Rocket series 2215 1950 Kv (model 86MA07)
- Batt is 3s 5800Ah 25c Zippy Compact
- GPS is installed and correctly configured including home location set
- Radio is Turnigy i10
- Receiver is Turnigy ia10
- All systems seem go in radio and receiver and with GCS as well as setups
   - Including end points, mixes etc, all zero'ed or -120, +120 respectively
   - NO TELEMETRY or SBUS add on's installed
   - Receiver is CORRECTLY BOUND and set up
   - Radio is set to AIRPLANE MODE

Any help would be greatly appreciated.

Thank you,

Scott
smorrison047

f5soh

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    • LibrePilot
Post your config file: File > Export UAV Settings...

Welcome

First of all - you're not going to believe this but we have the same exact name.  Too funny.

Anyway, I had the same issue with a CC3D Mini.  Eventually, I had to simply make sure the FC was pointed forward (dumb mistake on my part) and also that it was calibrated on a absolutely flat surface.  After those two were remedied, it worked much better.

Hope this helps.

Well Scott, then I must say that you have an absolutely freaking awesomely cool name!  Just do yourself a favor though, don't tell anyone you are me, it won't go very good, lol!

I did go over that stuff, over and over, and over and did I mention over again.  I recently found out that the possible problem may be that I am using Hobby King Blue series 30A esc's and have them set in the GCS as 490 Rapid and possibly should be set at 50.

I will get back to everyone with that and will also post the config file.

Thanks Scott,

Scott M

Thanks for the reply f5soh,

I will post that file here shortly.

Thanks,

Scott M

Here is the file, I have tried everything I can thus far, for whatever reason, even changing the esc to standard through the vehicle wizard and setting up the whole thing again, 1 motor (#4) still spins up to max.  I have swapped out esc's and am going to swap it out with yet another one and see what happens.

Thanks guys

Scott M

f5soh

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    • LibrePilot
You set the AlwaysStabilizeWhenArmed to TRUE
You can remove reset this option to False.

This means the board is always stabilized whatever the Throttle value.
For example, if you move your quad around Yaw axis just after arming two motor can go full rpm to compensate the move.

See this post about safety:
https://forum.librepilot.org/index.php?topic=506.0;topicseen

Output tab: you may set the output refresh rate to 490Hz, not 50Hz, for decent results.

I had a similar issue when experimenting with INS13, in that when I touched the throttle to ~1% my motors would ramp up to full throttle. Freaked me out. Combine this with the lack of external mag support in the current release and I disabled INS13 to comp for the time being.

I'll revisit gps modes when the next branch is released, or when I figure out how to compile it. I have no experience in software builds.

By the way, if anyone has a really dumbed down tutorial on compiling next branch, please do share!

I have the same situation with my build.  Its specifications are:
1.   SK Lightning 480 quadcopter frame kit
2.   Set of 4 Multistar Elite 2216 920 KV motors, 2 CW and 2CCW
3.   Open Pilot Revo 32 bit F4 based flight controller with integrated 433 mHz Oplink 
4.   4X Afro Slim 20A ESC with SimonK firmware
5.   Orange R1020 V2 2.4 gHz DMS2/DMSX compatible receiver
6.   Ground Control Station software downloaded from Librepilot.org running on an old Sony laptop
7.   USB cable with micro b connector
8.   Futaba 9C transmitter with Orange DMSX/DMS2 converter module.
9.     4000 mA 3C Nanotech lipo
For testing and setup, I've tethered my quad to a large piece of plywood to prevent it from lifting off more than a couple of inches.
When the throttle is "cracked" the motors start to spin up like a "soft start" sequence, but, after a few seconds, go to high speed
It's set up using the standard Wizard, with default settings, except for moderate exponential on the throttle curve (added in an attempt to control the behavior I'm encountering). 
The alwaysstabilizewhenarmed setting is False, and I use channel 5 on my transmitter for arming.
During setup, with no props, the motors seem to spin up smoothly and linearly, but it's hard to tell when there's no load on them.
When I install some old 6X4 props leftover from my 1/2A glow days, it starts up slowly, but rapidly spins the motors up.  They can't generate enough thrust for liftoff, but do jiggle the airframe around a bit.
With putting on the 10X4.7 props, all hell breaks loose, with the soft start followed by high throttle and lots of bouncing around at the limits of the tethers.  The airframe seems to respond somewhat to pitch, roll, and yaw inputs, but it's limited by the tethers.
My next plan for testing is to take the Revo out of the equation.  I'll drive each motor separately directly from the throttle channel (3) on the transmitter/receiver and use a tach to see if they spin up more or less consistent with the throttle stick.
I have a Hobby King KK2.1.5 board that I can swap for the Revo for further diagnosis.
Any other suggestions?
Thanks


Well, you definitely have the same problem as I have described.  I do not see where you have a GPS on your setup.  I just today changed the GPS to basic/complimentary and now it works and has resolved the problem.  However, right now as it stands, the board is basically a cc3d and all the GPS functionality is useless if I actually want to fly it.  I believe it is something with the firmware or in the programming that is afoul.  I do not know much about the software or drivers, but it is the only problem i'm having and everything else seems to work fine.  If I enable the GPS to insi13 (or whatever it is) then the system just spins the motors to max, well 2 of the motors, then the other two follow to compensate.

So, if you have a gps enabled, try setting it to basic / complimentary and that should at least get you flying.

Scott M.

jbarchuk

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For testing and setup, I've tethered my quad to a large piece of plywood to prevent it from lifting off more than a couple of inches.
When the throttle is "cracked" the motors start to spin up like a "soft start" sequence, but, after a few seconds, go to high speed

The 'after a few seconds...' thing. That's an invalid/faulty startup/launch. When you crack the throttle the FC immediately tries to stabilise the vehicle. It's still on the ground so the FC adds a little speed to motor(s) to try to level it. There's not enough thrust to fly so the vehicle stays on the ground and doesn't rotate in any direction, so it adds a little more motor speed, and more speed. Eventually it should flip over.

Back to your first post,

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When I arm the board, I apply a very slight amount of throttle to get the motors going and all the motors go to near max kv with that tiny bit of throttle.

Does that take 'a few seconds' to -start- happening? If yes, then again that's the FC trying to level the vehicle without having enough total thrust to move the thing.

You're overthinking all this. The FC gets reeeeally upset and confused when it can't do its job so it keeps trying harder. :)

A correct launch is to simply punch the throttle to about 50% to get the thing off the ground so the FC can do its job. Or crack the throttle to make sure all props are spinning, which can be seen within 1/4 second, and then punch the throttle to 50%.


Thanks for the tip.  It took a bit of a leap of faith to punch the throttle to get it off the ground, but it did work.  I even managed to get it back down again without major destruction. 
It's pretty jumpy in the air, with lots of motor surging, unintended altitude gain, and rapid descents and hard landings when I cut the throttle back to keep it from getting too high.  Directional control is fair, but not exactly smooth.
I'm sure there are lots of settings that need tuning, so I may go through several props and landing gear legs before I get it sorted out.

jbarchuk

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Thanks for the tip.  It took a bit of a leap of faith to punch the throttle to get it off the ground, but it did work.  I even managed to get it back down again without major destruction.

Awesome!! Rock! Roll! And FLY!!!  ;D ;D

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It's pretty jumpy in the air, with lots of motor surging, unintended altitude gain, and rapid descents and hard landings when I cut the throttle back to keep it from getting too high.

Next step is to add throttle curve. There's really only a very limited range of throttle that's actually 'useful' ESPECIALLY for beginners. Look in the Vehicle screen on the right side. I don't use this chart myself because the horizontal scale is divided into only 4 parts with the first segment at 25%.

The pics below record the evolution my throttle curve has gone through as I learn more.

The first pic notice that at 10% stick throw the throttle jumps to 48%. That's where my quad just barely hovers or even drops a little. Between there and about 30% stick throw is where I land at a slow controlled rate.

The line labeled 5, maxes out at 80% and before that it was 70%!

In the 2nd and 3rd pics over the course of months of learning and getting more comfortable I upped the max speed.

Note that each time I upped the max speed and used it a lot :) I LOST aboue a MINUTE of flight time, dropping from 7 to 6 to 4 minutes. More throttle = 'using more gas in the tank.'

Quote
Directional control is fair, but not exactly smooth.

Add a LOT of expo to slow the action on middle ranges of the sticks. Don't wham on the sticks. The correct way to fly is to not 'move' the sticks but to 'apply pressure.' Later with experience you can turn the expos down to get more reaction, and really -move- the sticks to make the vehicle react sharply. But you need practice first because you need to learn 'what will the vehicle do when I do this?'

Also add a -little- cruise control in Stabilization - Expert to help maintain altitude when inputting pitch and roll. By default Power Trim is set to 100. DON'T adjust it by a LOT!!!. Drop it by ONE point to 99 and try it and you will notice a difference. If it still falls fast in when you input pitch or roll drop it by a HALF point. Mine right now is 98.75 but it's pretty heavy as compared to stock with a gopro and FPV. Don't drop it by a lot or the quad my in a sense 'decline' to land because any stick input adds too much throttle and it's hard to make it descend.