A gimbal for your thoughts......

Ok folks here is the update on the gimbal. We got a 2D gimbal (BGC 2.2) and installed it on out Cheerson CX20 test rig, then performed our tests. Here are the results with our present test gear:

2700Mah stock battery: 
Clean: 15 minutes
Fixed Camera: 12 minutes
Gimbal & Camera: 7 minutes.

3200Mah Battery:
Clean: 17 minutes
Fixed Camera: 14:15
Gimbal & Camera: 10 minutes.

Now as to the performance and handling:

Clean: Very responsive. quite nimble. less than half throttle and it's still climbing.
Fixed Camera: a slight bit less sporty but still very active. about half throttle to climb
Gimbal & Camera: noticeably more sedate. Much less responsive. 60%+ throttle to hover.

Having a good look at the reasons, The fixed mount requires the steel mounting plates, the antivibration system and the protective camera case. The steel is thin due to it's strength and it doesn't need to be thick (& heavy) to do the job well. The protective camera case does give the camera a much better chance of survival in a crash but it does add weight.

For those that may be unclear on what a gimbal does, It automatically adjusts and compensates fore movement, for example: If you hold a bird in your hand, as you rotate it around, it will keep it's head steady and level. This makes taking pictures and especially video much better to watch.


This particular gimbal used in our testing weighs in at about 200 grams on it's own. For those still using the imperial system, that's almost half a pound, BEFORE including the camera. Factor in as well that the gimbal uses power to self level and if you tilt, it draws more power. (always try and get the camera as balanced as possible without power. It helps a lot).

                       The fixed mount on the left,          The gimbal on the right



The next thing that we ran into is that mounting this system had it's own challenges. It could not use the stock mounting location without blocking the very plugins needed to operate it.

 There was no satisfactory mounting options for this without some modifications and/or improvising. In the end we opted for attaching the mount further forward by attaching the mounting to the plate of the fixed camera mount.

 The factory CX20 camera mount

 The BGC 2.2 mount is much wider and MUCH heavier.

We used the standoffs to avoid any drilling (we did have to slightly widen 2 holes and drill one) This gave us a sturdy installation with the benefit that it's far less likely to see the rotor arms or landing gear in the shot.

 Hmm, what if we combine the 2?

 The standoffs come with the Gimbal.

 By mixing the 2 systems together, it works....at a cost.

 Remarkably sturdy 

Of course there is a few downsides. It alters the weight and balance. the front props have to carry a little bit more of the load than the back ones. not much, but it's there. The next factor was that we added even more weight (never a good thing) and finally, the standoffs took away the very tiny ground clearance between the bottom of the gimbal and the ground, It was literally resting on the ground. the worst of that is that the accelerometer for the gimbal is an open circuit board and contact with the ground (especially if wet) is a very bad thing.

2 points to note here: The camera is secured with a velcro strap and a collar that secures it by the  lens. A rubber band is a cheap backup plan. An if you notice the rubber vibration isolator on the left, a zip tie is loosely run through the rubber. If the rubber was to pull out of the plate, the nylon strap will make sure you don't come home with parts missing.

Option 1: Redo the mounting setup, drill lots of holes. A messy complicated bunch of changes.
Option 2: Use a different gimbal. going to be more money. This model is quite well priced. and since most parts come from China, Typically taking 3-5 weeks to arrive,
Option 3: Modify/ replace the landing gear. This was the option chosen. Apparently the landing gear from the Phantom series will fit and is taller. but again a long delay getting them....So a 15 minute solution was done in the workshop. I cut some lightweight 1/8 inch thick plywood. add a few blocks of 1/4" plywood where the dowel would connect the two halves. Drill holes for zip ties and we are in business.
Downside? it adds more weight again. It's not the prettiest or sleekest thing.
Upside? the gimbal and it's electronics are safer. The solution took minutes with what was on hand. And one of my gripes was addressed. The CX20 landing gear/skids are effectively only 12 cm long, even though they appear to be over 18. They are rounded and as a result, it can be prone to tipping forward or back. This is of particular concern if you land with any forward speed. Your props will hit the ground. This makes that much less of an issue.

As a  camera platform, the extra weight and the more sedate response make the quad better from a stability point of view. but it costs you a lot in endurance.

Now after a lot of discussion, there are a few options of using a different and possibly more efficient prop. We are going to do some measurements with some different prop options in a later segment.

My personal feelings on the matter (and a few others seem to be begrudgingly agreeing) that while this size of quad (350 class) can certainly carry a camera. This particular setup is heavy and is compromising the operation too much. If you look at the design of this gimbal, It could have been made of much thinner and lighter metal (it's aluminum alloy but a heavy one). There are many types of sturdy plastics that would be more than sufficient and would cut the weight down by an estimated third or better. Even the materials used do not need to be over 4mm thick for carrying a camera so light. When you are shopping for yours, make sure it is well under 200g.


PS. When we did our flight testing, the extended landing gear worked great.


We will be looking at lighter and more suitable gimbals, but this one will probably be put aside for the big build. (an upcoming series here)