Versacopter GR18 PID settings. Stability etc

[mmoore112]

Trying out the versacopter with the Gruapner GR18.

Has anyone tried the Gr18??

My experience is that it has very wild oscillations. Manual say may need to adjust the PID via telemetry. Which is fine.
I wonder if anyone else has had this experience and how did they overcome. Or, even some PID settings

Thanks in advance for any information.

I thought i would give the GR18 a try since Flattest video was using the GR18.

 

[Rickthejetman]

I am having the same issue. At full throttle the quad oscillates wildly. I read the manual and it says to raise the POWER2SENS setting for high power setups. This had little affect. I'm running RMRC 2204 2300kv motors RMRC 20A opto BLHeli ESC's and 6x3 props. Hopefully one of the members here or Flitetest crew can chime in with some advise.

 

[Darkback2]

I have a GR-18 and outside of plugging it in and changing the rate for rate mode so that I can do flips I haven't changed anything...That said, I haven't had any issues at all and all I did was plug it in. The tuning seems really tight, though perhaps a bit soft? I am running a 250 size quad with 20a escs, multistar baby beast motors and gemfan 5045 bullnose props.

I would love to start a graupner gr-18 support group because I haven't really be able to find much information on using it out there.

DB

 

[mmoore112]

So out of the box the GR18 works fine.?

Great, you know i maybe using to big of props 6x45 and 4s battery. Maybe, that is why the thing goes crazy.??
Maybe, i will try say 5045 and 3s.

Is the that what you used Darkback2?

It would be nice if Flittest would chime in. In the build video he goes out and it flies great. I wonder if there were some tweaks he did off camera.?



thanks

 

[Darkback2]

so my setup:

ZMR-250
Multistar baby beast motors2206 2150kv
Afroslim 20a esc with I believe simonk
3s 35c battery
Gemfan 5045 bullnose props

Hope this helps

DB

 

[Rickthejetman]

Nobody else has any experience or advise with this flight control? Starting to think I should not have taken Josh's advice to buy this.

 

[Rickthejetman]

O.K. today I got some flight time in, I maxed out the POWER2SENS no better. so I said screw it and went down with the POWER2SENS got all the way down to 0 it is now flyable but not perfect. Still wish someone from Flitetest would chime in for us.

 

[streek]

Versacopter PID help. Trouble getting it dialed in

I built the versacopter race quad version. I used power pack e and got a mz-12 gr-18 combo. The build went great and it flew good with the default settings on the gr18. I started messing with the pid's and have the pitch and roll locked in. I am having a issue with yawhat and can't find any answers. When I rotate the quad in a full 360 the motors speed up and the quad shakes. I am picky and want it totally rock solid. I went by the manual and first set P to the point when I would not overshoot. I then set D and my pitch and roll are rock solid. I then had to leave I at 5 which seemed really low. But when I raise it any higher the quad shakes when I roll it from side to side. If I keep it at 5 I can roll from side to side and it is rock solid. I am at a loss on why the motors speed up when I yaws left and right. I tries to adjust the yaws pid but it did not fix the problem. Any help would be appreciated. I also have videos with sound and you can hear and see what the motors are doing.

 

[ladykate]

Nobody else has any experience or advise with this flight control? Starting to think I should not have taken Josh's advice to buy this.

So much depends on PID settings and the best bet might be to start by clearing I and D and then bringing P up until it is unstable and then backing down 10%. Then adjust I and D to filter out overshoot and wobble.

I browsed this thread because I wanted to find some PID settings to get me close on 4S with a Versacopter like quad. It works out-of-the-box with 3s (and very well). I'm going to have to take my own advice and start from scratch, I believe.

EDIT: This morning I put I and D at min on all settings and then put P at 10 on all settings. That allowed me to fly. After some fiddling, I backed P down to 7 and right now I have D at 10 and I at MIN. This is with a QAV250, Luminier 2208-9 motors, 4s 1350, 5045 props and 20A escs. I am not tuned but I can reliably fly it. In Attitude mode it is probably good enough, in Rate (Acro) mode it needs a little work - probably more D. It will punch out reliably in both modes. As always YMMV (Your Mileage May Vary).

EDIT2: So... what I learned while flying. Damping and Power2sens interact with the PIDS - a lot. So does Roll Factor % and Agility for yaw. So not only do you have the normal PID interaction, there are four other factors that come into play. My current PID setting (which is getting closer to OK) is Roll/Nick 20, I 5, D 10, Damping 0, Power2sens: 60 (check out the specs on the quad above). Still not tuned great but quite flyable. I arrived at this by setting I and D to MIN and then upping P and decreasing Damping and Power2sens until I got what I imagine to be a reasonable figure. Then increasing D until I got crap and backing off. I is just a guess - I couldn't detect a rise when pulling back at half throttle in Rate (as described by the manual) but I added in 5 just because. YMMV I left Roll Factor and Agility at factory settings but I'm sure both need to be adjusted.

To some extent, one might be able to leave the factory settings as is and adjust Damping, Power2sens and Roll Factor only. Just guessing but the interaction of seven different values is somewhat confusing. Still - I like the receiver so I'm pressing on.

 

[ladykate]

I built a Goby 180 size frame with 4s and used the default settings and just adjusted the damping, power2sens and a little P and it seemed to work fine. Crazy interactions going on with this. Still - fun to play with.

 

[Darkback2]

I've been playing with my PID settings, Problem for me is that I fly almost all the time with 3s, but then swap to 4s when I am using my 360 camera. (Can't take off with it in 3s.) I am not feeling the idea of changing my PID settings when I add the camera so I am dealing with some wobble at full throttle on 4s. At this point I realized my quad is just like everyone elses, just the way you do things is different. On 3s I turned I and D down to nothing and then adjusted P until I was happy...~40 in my case, then I increased I until I got vibrations and then went back down a bit, and did the same with D last. When I add the camera I get crazy vibrations at full throttle, but the quad is relatively responsive and controllable.

I really want to find a way to set the throttle so that if I cut the throttle all the way I still have authoritative control. There is supposed to be a way to set that with a switch, but I haven't figured it out yet. When I do I'll post a video showing how to do it.

Hope this helps someone out there.

DB

 

[ladykate]

Darkback2 - don't you just want to increase your idle throttle (done in rx settings)?

I'm still messing with tuning the quad on 4 cell but it is getting closer to good - here is a link to a maiden after several mods (I had a mystery problem that ended up being an intermittent camera - this is a wring out to make sure it wasn't going to fail again.) I ended up frying four motors a month or so ago so I went with better motors and the PIDs changed a lot. It is interesting that just about anything will cause PIDs to need adjustment.

https://www.youtube.com/watch?v=S0L_t79of6U


Oh... and the Graupner rx strength reading helped me find the Goby when I crashed (failed video) in the weeds that you see in the above video. Just held my hand over the tx antenna and used it to direction find. The rx strength reading is better than a beeper - especially in this area where there are winds, bugs, and birds that create such a din that you can't hear a beeper that is buried in 6' tall weeds.

(cross posted to RC Groups)

 

[Darkback2]

Hey Ladykate,

Great Flying! I don't think I could fly like that so close to the water :-o !

So t...I posted a youtube video showing how to setup a kill switch and minimum throttle a little bit ago...I'm not sure that all of the steps are necessary, but this is the best way that I found to do it that seems to work consistently. I ended up setting it so that the throttle cut off switch works for the full throw of the throttle stick, but that is actually a bad idea because you can accidentally hit the switch at full throttle...(bad idea.) I have the acro/self level switch on one side, and the throttle cut off on the other...In a panic I hit the wrong one and my quad fell to the ground from a pretty good hight...Luckely I landed in a pricker bush. :-(

I'm starting to love this controller. I feel like I'm starting to get things figured out to the point where I am happy. I still need more D, but I'll get that also eventually.

Using the video signal to find you quad is a great idea...I ran into that when the wind blew me into a tree on the complete opposite side of the field I fly than I thought...I searched the wrong tree stand for about 10 minutes before I realized I kept loosing RX signal when I walked in a certain direction and gained it back when I walked the other way.

Happy Flying!

DB

 

[ladykate]

Hey Ladykate,

Great Flying! I don't think I could fly like that so close to the water :-o !

I showed up at the field one day and a guy was looking out over the marina. About 100 feet out you could see the twin antennas of a quad sticking up out of the water. The marina is a mud pit on one end for the most part. The guy had to crawl on his belly out over the mud and get the quad. The quad was ruined but it was kinda funny. Even he was laughing.

So t...I posted a youtube video showing how to setup a kill switch and minimum throttle a little bit ago...

DB

It is different for my tx (MZ-18). Thanks for the video because I think I need to re-look at the way I did it. Mine works but could be better.

 

[Darkback2]

I showed up at the field one day and a guy was looking out over the marina.

You must be a curse. Yesterday I fail safed my quad into the bay. Luckely it was low tide, but it still cost me an ESC, a motor, and my go pro. :-(

Quad is back up in the air...Go pro not so lucky. I am most likely going to replace it with a Xiaomi Yi though because clearly I can't afford to have nice things.

On another note, I am running the GR-18 on both my blade 150 and my alien 5 inch. The blade P setting is 100 (still no wobble which makes me think I need to change some other setting) I is at 15, and D is at min. With my 5 inch P is at 40, I is at 10, and D is at 25.

The 5 inch wobbles crazily when I fly it without the weight of my go pro, and there is still significant bounce when I do fast flips.

Yaw rate seems slow on both quads.

DB

 

[ladykate]

I get better response from the NAZE32 setups than the Graupner but it is close enough to make using the Graupner fun. On attitude mode it is very stable - I was flying it up and down the street and around the neighbor's trees this afternoon - testing it after losing a prop in the air. It was locked in and very easy to control. In rate mode it is less responsive than the NAZE32 in Acro but it is still OK. Like you, I'm still messing with PIDs. There are several things that affect the price of eggs besides the three basic adjustments. I feel like I'm missing something.

Sorry to hear about your dunking. I managed to crash mine hard - twice - but it still is flying. The first time I hit asphalt at the bottom of a four roll stunt and the battery ripped off, caught fire and burned on the pavement. The crash broke the platform I was using to hold the rx but that was all. The Goby frame is tough as nails - and apparently the GR-18 is impact proof ;-}. The last crash was when a prop snapped at altitude and I managed to hit that same stretch of asphalt (our runway). Luckily I didn't have a camera on it or else it would have been toast. The quad bounced about six feet in the air on impact.

I like the Mobius or RunCam. GoPros are too expensive for quads (IMHO). the Mobius and RunCam take crashes better, are cheaper, lighter, and the footage is plenty good - especially for YouTube or email.

 

[Darkback2]

The only thing I have to compare it to is my Naza-M Lite which was "upgraded" to a naza-m v2. In that case the upgrade made a huge difference in handling, but compared with the graupner there is no comparison. I need to grow up and eventually will build a quad with a naze 35 or the like...

As for the crash, I replaced the camera with a Xiaomi Yi. Honestly outside of some cosmetic differences I can't really tell the difference considering what I am trying to do.

When I get my 360 camera back that will be a different story.

I think I am on the verge of a good tune. Today I felt like I could pretty much think it and make it happen...(a bit of an exageration) I felt like i had the best control I have ever had. The Nick rate is probably a little bit high because I keep missing the half way point on backflips...(I'm trying to be like FGA) and the I is now a little bit high. I'll tune that better tomorrow provided I remember to charge my batteries.

I'll edit down a video soon showing what I have learned and what I have done.

DB

 

[ladykate]

Well... time has passed and I'm learning more about the Graupner GR-18 and the MZ-18. The big thing I learned was that my stick calibration was off. I realigned it a week or two ago and went back to the three models I'm using Graupner on and there was a world of difference. Funny that even a little mis-alignment causes issues. The Goby I use (GR-18) and a Seriously Dodo with a GR-12L are both working fine. I still don't have the agility I want but it is getting very close and both quads are flying great. Here is a video of a very slow march around my backyard using a Goby (180mm) and a GR-18. No acro but the stability of the Graupner is superb.

https://youtu.be/cO8UFXC_DZ0

 

[Darkback2]

Is your yard on a slope or was your camera crooked? I found myself tilting my head through the whole video.

 

[Darkback2]

For me increasing D was the key...I think. Things were a little bit hot after a flight I had the other day, but then again it was also over 90 degrees F out at the time. I'm hoping I don't burn anything up. I've heard I should reduce P and I now a little bit to compensate, but flying feels so good right now.

I also got to fly my old NAZA-M based ZMR this past weekend. (I gave it to my nephew who lives in Los Angeles...) I honestly can't believe I flew that thing. The tune wasn't horrible, but it was nothing like my Graupner. Now where it gets really hard is, how would I feel flying a Naze 32?

DB