DJI Osmo Mobile Gimbal Modifications
The DJI Osmo Mobile gimbal is an amazing stabilizer for smartphones. The battery life of my iPhone 6s or other smartphone is abysmal when recording video. The DJI Osmo Mobile gimbal's battery will last several hours, but between the two, it's a struggle to keep everything powered.
DJI sells an accessory that replaces the battery, powering the gimbal from an external power source. A 12V to 18V lithium power tool battery falls within the input voltage range. I choose to use Ryobi 18V system since I have a lot of them. The cheapest tool to hack and salvage the battery holder portion is the older 18V flashlight. It's grip is very close in size to the Osmo Mobile grip, which makes it easier to make an adapter to attach the battery to the Osmo Mobile handle.
Starting with the Ryobi 18V (incandecent) flashlight, I cut the head off right below the trigger. This leaves enough space inside the grip to store the excess power cables. The cross section of this area is very similiar to the face of the Osmo Mobile battery opening.
To attach the Ryobi flashlight base to the Osmo Mobile grip, I designed and 3D printed an adapter from polyurethane TPU. The TPU is flexible to conform to the shape, stretchy, and extremely strong. The connection is rigid enough to keep the gimbal stable and upright, and flexible enough to absorb bumps and bending.
DJI Osmo [Mobile] handle to Ryobi 18V flashlight adapter
Link to the OnShape CAD document.
The 3D printed adapter is glued over the cut off top of the 18V flashlight handle using high strength hot glue. Apply a liberal amount of hot glue on high heat around the top of the flashlight handle, and then slide the adapter down until the handle is halfway through the adapter. Run a bead of hot glue around the edge of the adapter where it meets the handle. Let this cool and harden before moving on.
10-32 (or 5mm) screws and nuts are used to tighten the adapter onto the Osmo Mobile handle. This makes it easy to attach and remove. The 18V battery packs have been so convenient and working well, that I haven't had the need to remove it.
DJI makes an external power accessory for the Osmo gimbals. This gets inserted in place of the battery, and a new door is attached on the battery compartment that allows a cable to pass out. I didn't have the mating connector for the DJI power adapter, so I cut and soldered the cables to my own connector that is smaller and fits better in the small space in the flashlight handle.