GGoodrum
Member
I decided to start this thread to document the testing we are doing on this new gimbal/mount setup for the new DJI F550 hex setup. While doing the build, I was quite pleasantly surprised to see that not only was I getting very fast GPS locks, even indoors, my pesky gimbal drift problem, once the GPS was locked in and active, had vanished! Well, when I'm wrong, I'm wrong. 
As part of the new F550 Hex build, I decided to use the newer GPS module that Sidney sent me, via Robert, mainly because it had a longer cable than my original unit. Anyway, I had tested this unit, before, but I was still seeing the same gimbal drift problem, so I continued to use the old module, as it was already mounted. On this build, I had a new mounting for the GPS antenna/module, on a small aluminum plate that is attached to the upper F550 plate. This gets the GPS as far away from the IMU as possible, but the old module cable wouldn't reach. With the new one, I also put a couple pieces of copper tape on the underside of the GPS module, before attaching it to the mast. This is the tape XA provided with their v1 GPS module, for putting on the inside of the dome.
First thing I noticed, when I fired up the WK-M, with the Assistant connected, is that it only took about 45 seconds to get a full GPS lock, and this is indoors. :tennis: With the old module in my old setups (VC-600-X8; XA Hexa...), It usually took 7 or 8 minutes, just to go from 3 flashes to 2 flashes. After the initial shock wore off, the second thing I noticed is that the gimbal drift issue was gone as well. I really don't know what to say. Maybe Frank was right all along, and most of my problem was hardware related, or maybe the new 5.02 firmware, in conjunction with the new module fixed it, or maybe it has something to do with that, and the new gimbal's "tuned" deadband spacing I'm uisng (deadband is programmed to be 1ms...). I'm totally at a loss to explain this, but at this point, I'm just so happy it's working right that I really don't care. :frog
In the video below, it is clear that with the GPS active (1 red flash, or less...), there is clearly none of the "twitching" that we'd see around the neutral point. I've got the gimbal gains dialed in pretty well. I know this is not $2k DJI gimbal-like performance, but it is pretty damn close. This is with 12-bit digital servos, running on 7.4V, and it's using the "stock" WK-M gimbal outputs. The speed of these servos, on 7.4V, is about .10 seconds. I'm also going to try another version that is about .06s on 7.4V. We went with the torque-ier, but slower, versions initially, but that was overkill, especially the GoPro version.
In any case, the proof-of-pudding, so to speak, will be to see how it does with real airborne footage. That is the next step. I just need to balance and install the props, which I hope to do before the SB starts later.
We will have two versions of this available (starting next week...), one like you see here, that is optimized for use with a GoPro, in its protective case, and second, slightly larger version that is sized to fit a NEX-5/7, a GH2 or a 550D. There will also be an option for an "inline" version of GoPro gimbal/mount for use on a F450 quad. The F450 inline GoPro mount will be $375. The F550 hex version of the GoPro gimbal (shown below...), with the integrated landing gear mount, will be $475. The larger NEX version of the same thing will be $500. We will also offer a combo deal that will include both the GoPro and NEX yoke/tilt assemblies for $700. It only requires removing three screws and loosening a set screw to swap the two yoke/tilt assemblies.
Anyway, I'm working to get my old TPpacks.com site "reborn", to make these available on, and Bart is in the process of setting up a vendor support section here.
-- Gary
As part of the new F550 Hex build, I decided to use the newer GPS module that Sidney sent me, via Robert, mainly because it had a longer cable than my original unit. Anyway, I had tested this unit, before, but I was still seeing the same gimbal drift problem, so I continued to use the old module, as it was already mounted. On this build, I had a new mounting for the GPS antenna/module, on a small aluminum plate that is attached to the upper F550 plate. This gets the GPS as far away from the IMU as possible, but the old module cable wouldn't reach. With the new one, I also put a couple pieces of copper tape on the underside of the GPS module, before attaching it to the mast. This is the tape XA provided with their v1 GPS module, for putting on the inside of the dome.First thing I noticed, when I fired up the WK-M, with the Assistant connected, is that it only took about 45 seconds to get a full GPS lock, and this is indoors. :tennis: With the old module in my old setups (VC-600-X8; XA Hexa...), It usually took 7 or 8 minutes, just to go from 3 flashes to 2 flashes. After the initial shock wore off, the second thing I noticed is that the gimbal drift issue was gone as well.
I really don't know what to say. Maybe Frank was right all along, and most of my problem was hardware related, or maybe the new 5.02 firmware, in conjunction with the new module fixed it, or maybe it has something to do with that, and the new gimbal's "tuned" deadband spacing I'm uisng (deadband is programmed to be 1ms...). I'm totally at a loss to explain this, but at this point, I'm just so happy it's working right that I really don't care. :frogIn the video below, it is clear that with the GPS active (1 red flash, or less...), there is clearly none of the "twitching" that we'd see around the neutral point. I've got the gimbal gains dialed in pretty well. I know this is not $2k DJI gimbal-like performance, but it is pretty damn close.
This is with 12-bit digital servos, running on 7.4V, and it's using the "stock" WK-M gimbal outputs. The speed of these servos, on 7.4V, is about .10 seconds. I'm also going to try another version that is about .06s on 7.4V. We went with the torque-ier, but slower, versions initially, but that was overkill, especially the GoPro version.In any case, the proof-of-pudding, so to speak, will be to see how it does with real airborne footage. That is the next step. I just need to balance and install the props, which I hope to do before the SB starts later.
We will have two versions of this available (starting next week...), one like you see here, that is optimized for use with a GoPro, in its protective case, and second, slightly larger version that is sized to fit a NEX-5/7, a GH2 or a 550D. There will also be an option for an "inline" version of GoPro gimbal/mount for use on a F450 quad. The F450 inline GoPro mount will be $375. The F550 hex version of the GoPro gimbal (shown below...), with the integrated landing gear mount, will be $475. The larger NEX version of the same thing will be $500. We will also offer a combo deal that will include both the GoPro and NEX yoke/tilt assemblies for $700. It only requires removing three screws and loosening a set screw to swap the two yoke/tilt assemblies.
Anyway, I'm working to get my old TPpacks.com site "reborn", to make these available on, and Bart is in the process of setting up a vendor support section here.
-- Gary
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