I have a BlueROV2 heavy version, and a DTG3. What I really like about the DTG3 is the possibility to rotate the grabber, which is not possible on my bluerov2.
Then my question: Is it possible to mount the DTG3-grabber on the BlueROV2 with the same functionality? If so, I imagine there might be some technical steps, but how difficult will they be?
Hi @Truls.marinrep, welcome to the forum 
As far as I can tell DeepTrekker doesn’t provide public documentation for how the DTG3’s grabber is controlled, so while most things can be adapted for use with ArduSub and/or BlueOS you would need to either ask DeepTrekker for the control protocol and electrical specifications of their grabber (which they may not be willing to provide), or reverse-engineer it to determine that information.
ArduSub is set up for easy control of servo motors, so if it turns out the DTG3 grabber operates on servo-style PWM signals (like our Newton Gripper does) then integrating it could be quite straightforward. If it uses some other signal protocol and/or a supply voltage that’s not already present on a BlueROV2 then the integration could be more complicated, although I imagine the hardest part will be getting the information about what type of signal it uses.
In terms of physical mounting, there’s no established mounting solution that’s been developed for it, so you would need to design and make that yourself, or hire someone else to do so.
Alternatively you might want to consider buying an underwater servo and using that as a rotation axis for a Newton Gripper. This would also require a custom mount (and some care not to over-twist the gripper’s signal cable), but is potentially easier to get with a well-documented control signal.