Since I started writing the “Installing the Pixhawk and X8R on F450” blog posts, I have decided to modify my FY G3 Ultra 3 Axis Aircraft Gimbal mounting to make it a bit more stable and properly fitted.
For that I decided to go with top plate supported carbon fibre tubes. 10mm outer diameter and 500mm length which I shortened later.
I kept the mounting really simple using cable ties run through the F450 arms as pictured below.
The 10mm height gave me a good clearance to mount my led control board and cables in between the tubes and under the APM base.
I then mounted the APM 3d printed Base with more cable ties and the Pixhawk sat on it with two pieces of Moongel / stagg gell.
As the gimbal would now sit quite forward I had to move the battery as far back as it was needed to keep it balanced. I learned that keeping it balanced is very important during test flying my previous build.
I mount the battery at the bottom of this mount (pictured below), rather than the top as it helps with cable management and save my fingers in case the props decide to spin while I unplug or plug in.
On both ends of the CF tubes I inserted rubber rings that would act as stop for both the gimbal and the battery mount.
Those rubber rings were reclaimed from an unused undercarriage pictured below.
Next I plugged the X8R receiver back at the top of the bottom plate, and connected with the S.BUS cable to the RC pins of the Pixhawk. The antennas have been mounted with velcro on the F450 arms.
Finally in my previous built I used wooden lollipop sticks for legs which broke in my first flight due to the added weight of the gimbal (they were fine on a lighter copter).
These come with 4 screws for each leg, however I only used the 2 for each and hope for the best 🙂
With the following set-up the copter weighs 1685 grams and felt very solid. The flight was nice even though it needed a bit of more determination on the take-off as it’s a bit heavy to lift and the weight far from the centr even though it’s balanced. I might be able to improve that by tuning the PIDs in the Pixhawk a little bit more.
I must also mention that in the GoPro Hero3 video footage unfortunately I experienced a jello effect which I will try to resolve in the time to come.
I have added some Stagg gel at the point that my CF tubes touch the F450 top plate however that didn’t seem to help a lot. I suspect the issue is that the top side of the copter along with the stiffness of the CF tubes transfers vibrations a lot more.
Once again I used Stagg gell this time directly on the GoPro base of the gimbal. You can see the results in the following video
After a longer flight in the park (and as it’s visible in the below video) I realised that still that method still produced some jello at different times and subject to lighting and motor RPMs. So I went on Facebook on a page specifically for the FyG3 Ultra gimbal and asked the question of what else I could do. I was pointed to a Dubro balancer and the video below explaining how to balance blades and motors together. After I followed these suggestions I put everything together and I am happy to say that I have reduced the transfer of any vibrations to the minimum.
- DJI F450 Flamewheel kit (includes 4 x DJI 30 Amp OPTO ESC)
- Pixhawk bundle flightcontroller
- 3DR Telemetry module V1
- APM minimosd
- 3DR uBlox GPS with Compass Kit
- FrSky X8R Receiver
- 5.8 Ghz Video Transmitter
- FY-G3 Ultra 3-Axis Brushless Gimbal
- 10 inch Carbon Fiber Propellers