After much searching through endless listings for Brushless Camera Gimbals on eBay one thing that struck me was that almost all of the gimbals were not particularly lightweight. Most were made from G10 or aluminium and most involved lots of plastic clamps and bolts. There had to be a better design that was both very light and very strong. Carbon fibre seemed to be the answer to that requirement, however the designs that do use carbon fiber tend to stick with tubes and clamping those tubes together with plastic clamps. Even still they all ended up being around 400g without the camera.
Soooo, from past positive experience with 2mm carbon fiber plate I decided to start with a design for a frame that would cater to Sony NEX sized camera's and smaller. This apparently required me to use 4008 size rewound brushless motors (about 45mm in diameter and 20mm deep). So the design revolved around those dimensions. I also had to take into account how it would attach to the underside of my hexacopter (also made from carbon fiber). In my case I had already installed tall landing skids which look like this (very cheap on eBay) -
I replaced the plastic tubes with hollow CF tubes to reduce the weight. Using the distance between the two 12mm upper tubes I designed a method of attaching to them that reduces vibrations, using rubber grommets, and allows for fore-aft repositioning to find a good balance point. The final gimbal design below does not require any bolts to hold it all together, just small pegs that slot in tightly to lock it all in place and a dab of hot glue stops them from vibrating out in mid flight - which also allows for disassembly just by heating them with a hot air gun. The only bolts required are to hold the motors in place. The Martinez or AlexMos controllers with 45mm hole spacing then attaches to the bracket behind the roll motor. Weight with the large 4008 motors ended up being close to 220g. Keywords - Light, Strong and Simple. Final rendered design below -
If you are using Chrome give this a go - http://168.63.167.21/gimbal.html. This is a 3D version that you can interact with which gives you a better idea of how it all holds together.
And the prototype attached to my hexacopter -
Test video using the GoPro (anyone want to donate an NEX to test???)
Just in the process of getting a test sample CNC cut to see if it all comes together as nicely as the hand cut prototype. If that goes well I will order 50 and see if I sell them all (thinking $90USD for just the frame and all the fixing). Yet to find 4008 size motors that are under $50 each so a complete kit with all the electronics will probably sell for around $250USD. Not a bad price if you compare it with the NEX size gimbals being sold on ebay. Even the little RCTimer GoPro gimbal that is selling well at the moment is sitting around that price.
I will also srink this design down for GoPro only sized cameras and offer that up as a cheaper and lighter alternative to the RCTimer aluminium gimbal.
Happy to hear any expressions of interest - and gladly take on any contructive feedback.
0 comments