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Old Mar 02, 2012, 06:17 PM
formerly Juddkleinman
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Paonia, CO
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Originally Posted by GGoodrum View Post
I've added a CC 10A programmable BEC that will drive the gimbal servo at 7.4V.

-- Gary
Can you explain exactly how the BEC wires in to drive the Gimbal servos?
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Old Mar 02, 2012, 07:12 PM
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South Orange County, CA
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Originally Posted by R Hudson View Post
Those props they sell ARE the GWS props. I think that if a person really wants the GWS props, they need to be comfortable ordering enough of them to weed through and pick out the best ones that track well and discard the rest. Or go with the Graupners.

I have not used the Graupners yet but I LOVE the GWS props when they are good molds. Smooth as butter once balanced properly.
I agree, I love the 9x5x3 GWS props,. but you definitely have to pick ones without the bent tips. About 10% of the ones I have here are bent. The good news, however, is that you can buy 5 of the GWS props for the cost of one Graupner.

-- Gary
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Old Mar 02, 2012, 07:14 PM
manual flying apologist
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United States, CA, Fresno
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you make a custom cable from a servo extender cable.....

split the singal wire off of the ground and 12v+. you have 2 male ends and 1 female end on the same servo wire.

then plug the signal wire into your stabilization controller and the 12v and ground into the CC BEC.

but make sure the Controller and BEC have the same ground (common ground) otherwise it will not work.

so you cannot power the servos off a different battery than your controller, unless someone else knows something different. This was my experience.
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Old Mar 02, 2012, 07:39 PM
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Quote:
Originally Posted by juddkleinman View Post
Can you explain exactly how the BEC wires in to drive the Gimbal servos?
You need to have a special Y-adapter that you can make up (see attached...). This adapter plugs into the CC BEC, and then the two output leads plug into a pair of standard servo Y-adapters. The servos plug into the other leg of the "Y" and then you remove the red wire from the "output" lead and then it plugs into WK-M/Naza.

The net result is that power to the servo comes from the BEC, not from the WK-M/Naza.

-- Gary
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Old Mar 02, 2012, 11:14 PM
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Sorry I haven't posted an update sooner, but I've been swamped, doing some last-minute changes/improvements, and I wanted to thoroughly test them first. Basically, what I've been working on is better vibration isolation. With some help from Chris, at Vortex Aerial, we found that the pool noodles I was using, were causing a low-frequency oscillation, mainly due to prop wash. I've now removed these, and will add some LED strips, to help with orientation.

We also figured out that we need a different scheme for the first-level isolation. We found some silicon 2-piece grommets that are extremely pliable. Anyway, these have really cut down the vibrations. We did a test where Chris hovered in front of me. I could touch the F550 legs/arms, and you can feel a strong vibration, almost teeth shaking. Anyway, now when you touch one of the landing gear legs, or one of the skids, you just feel a very slight vibration. When you touch the mounting plate/battery tray, you get nothing.

In the video below, I hard-mounted one camera to the top F550 plate, and i'm using the GoPro yoke with a GP2. It was pretty windy, and the WK-M ws struggling to hold position. The gimbal video is raw, no stabilization at all:

F550 GoPro Gimbal Test-16.mp4 (2 min 34 sec)


The camera I used for the hard-mount has a stabilization/anti-shake function that can't be shut off, so the vibes aren't really quite as bad as the video would indicate. I did another flight a bit later, with a different camera on the top plate. The winds had died done a bit, so there wasn't quite as much movement all over the place, and there was a lot less jello.

I've ordered a bunch of the new silicon isolators,, which should be here Monday. I'm also going to try to finally get my website up and running this weekend.

-- Gary
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Old Mar 02, 2012, 11:47 PM
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Quote:
Originally Posted by GGoodrum View Post
I've been working on is better vibration isolation. With some help from Chris, at Vortex Aerial, we found that the pool noodles I was using, were causing a low-frequency oscillation, mainly due to prop wash. I've now removed these, and will add some LED strips, to help with orientation.

We also figured out that we need a different scheme for the first-level isolation. We found some silicon 2-piece grommets that are extremely pliable. Anyway, these have really cut down the vibrations. We did a test where Chris hovered in front of me. I could touch the F550 legs/arms, and you can feel a strong vibration, almost teeth shaking.Anyway, now when you touch one of the landing gear legs, or one of the skids, you just feel a very slight vibration. When you touch the mounting plate/battery tray, you get nothing.


Interesting about the pool noodles. I like them because they will soften a hard landing and make it easier to land on uneven ground like a rocky stream bank.....

but if they are making vibrations......


prior to today I have 0 first level isolation. So today when i got home I used some rubber grommets from a computer fan vibration kit, they are not all that soft, but i figure they are better than nothing.... So I added 12 of them

Then I also mounted the Nex-5n on moongel.... i cut a hold in the middle of and used rubber washers to sandwich the moongel.... then tightened the tripod screw down.

I also noticed that I had 1 prop adapter that was slightly bent... replaced that.

then i bought the dubro prop balancer (i own the top flight) and rebalanced my props with the new balancer.

after all that I have decent results..... much better than prior, but still some small vibrations when hovering (like a resonance frequency) and decending.

I have some video ill post in an hour or so.

I will follow suit with the pool noodles and more isolation to the landing gear and mount.




Aksman's Gimbal Test Night Time Nex-5n Hoverfly Pro (2 min 34 sec)
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Last edited by Adidas4275; Mar 03, 2012 at 01:17 AM. Reason: video uploaded
Old Mar 03, 2012, 06:01 PM
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very close adidas. and remember night flight is always more demanding, so it is good test to setup. good flight. I am impressed with smoothness of flight though.

We are in the final stage of fine tuning the gimbal in terms of setup routine. I know gary's website is also close to being ready to go. Doing due dilligence takes time and it took us bit longer to get here than we wanted to, but we are really happy with result we are getting.
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Old Mar 03, 2012, 09:32 PM
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Yes, Adidas, that is much better.

I made some major progress as well. Below are a couple of videos from today. The first one is just a ground test, after tweaking the gains a bit more. I'm quite happy with the setup now.

F550 GoPro Gimbal Test-18.mp4 (0 min 21 sec)



The next one is a test flight that I did shortly after the ground test. You can see how effective the vibration isolation is now, as there's a fair amount of jello in the hard-mounted GP video. None of it comes through to the gimbal GP, though, which is a good thing. You can also see how aggressive the WK-M is in trying to hold position in the face of some pretty gusty winds. If you just watch the gimbal GP video, you really don't see that.

F550 GoPro Gimbal Test-19.mp4 (3 min 45 sec)


About halfway through there's a really big hawk that does a "drive-by". This guy has a wingspan over 5 feet, although that is hard to tell in the video, due to the GP's ultra-wide FOV. This Hawk, and its mate, have a nest nearby, so we see one or both of them occasionally. Once the one here sat on our fence railing. That's when I saw just how big he was. Anyway, once he figured out he couldn't mate with or eat the hex, he was on his way.

I also added some LED strips, to replace the pool noodles to help with orientation. It is amazing how easy it is to see these, even looking directly into the sun.

-- Gary
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Old Mar 03, 2012, 09:50 PM
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Yes those LEDS are blinding At night up close!!!!
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Old Mar 04, 2012, 05:43 AM
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Chalfont St Giles, Bucks, UK
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Quote:
Originally Posted by GGoodrum View Post
after tweaking the gains a bit more. I'm quite happy with the setup now.
-- Gary
Hi Gary
Just a recap. To get to the point you are at now, is the gimbal plugged up to the WKM or is it plugged up to the Xaircraft FC and AHRS?
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Old Mar 05, 2012, 11:20 AM
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Gary,

If that is your neighbor in the beginning............I like him!
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Old Mar 05, 2012, 11:20 AM
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South Orange County, CA
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Quote:
Originally Posted by Paul@SCC View Post
Hi Gary
Just a recap. To get to the point you are at now, is the gimbal plugged up to the WKM or is it plugged up to the Xaircraft FC and AHRS?
Sorry, I missed this. Anyway, yes, this was with the XA v1 FC/AHRS acting as a standalone gimbal controller. I've done the same tests, using the WK-M's gimbal outputs, with similar results. With the XA's output rate set at 2ms/500Hz, the outputs are a bit smoother for small movements. If I set the rate to 10ms/100Hz, I can't tell the difference between the XA and WK-M outputs.

Here's the video with the WK-M driving the gimbal:

F550 GoPro Gimbal Test-22.mp4 (3 min 40 sec)


The gains are off just slightly, but all-in-all, the resulting video is quite usable. You can see in the video from the hard-mounted GoPro that there's quite a bit of jello, so the vibration isolation is working well.

One other thing I like about using a separate gimbal controller is that it frees up a WK-M channel so that I can use v3 to control the Attitude gains. I've also assigned another pot to fine-tune the roll axis center point.

-- Gary
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Old Mar 05, 2012, 12:12 PM
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Originally Posted by GGoodrum View Post

One other thing I like about using a separate gimbal controller is that it frees up a WK-M channel so that I can use v3 to control the Attitude gains. I've also assigned another pot to fine-tune the roll axis center point.

-- Gary
Can you explain what "fine tune roll axis center point" means?

Would you say I can use my WKM or is a separate controller for the gimbal the best route?
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Old Mar 05, 2012, 12:42 PM
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from our experience, if you want maximum performance, you would be best served with separate controller that has high rate output. But, we do get good performance out of the wkm built in output that probably is acceptable for most people. so, it really is upto the individual to decide what is desirable. Currently, XA FC seems have the best gimbal output due to its high output refresh rate of those that we tried. have not tried the new HF gimbal or picloc. basically you want the camera gimbal output to have 400hz rate for max performance. (digital servo only)
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Last edited by askman; Mar 05, 2012 at 01:08 PM.
Old Mar 05, 2012, 12:57 PM
manual flying apologist
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United States, CA, Fresno
Joined Mar 2011
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is this the controller you are using?
http://www.allerc.com/xaircraft-fc-1...er-p-6273.html

I have not used any XA stuff, you just hook up a RX to the FC and then hookup the servos and configure it...?

at $130 price point that seems like a great option.... used would be even cheaper....
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