Awesome! Are you using the BlueROV1 frame configuration? How are you communicating with the arm?
So, this is a hybrid, it actually have 7 T200 thrusters giving us 6 DOF. Developed for one of our clients, the guys on the sticker. We call it SIBIU
Hi all, in this test we are using an external driver for the Arm, but the electronics are designed for giving the system a servo-like control, so it is compatible with the aux outputs from the Pixhawk. The idea is that everything (ROV+Arm) will be controlled by the same gamepad.
Neat, looking forward to seeing the code for that once its done!
Roy may you post it on your NIDO Robotics facebook ? I cannot see it through here nor youtube.
I have made a 4 finger gripper arm using a lead screw attached to an M200 motor but am running it off channel8 with the latest QGC version which treats the motor like a camera servo on that channel. That works well enough for testing the efficacy of the mechanism but I don’t have the control I want over the speed so I want to be able to operate it like a thruster motor but independent of the normal thrusters. I know there must be simple way to get that channel to do that and was wondering if anybody else had fooled around with the settings to achieve the same thing.
Hi @johng, it’s cool that you are experimenting, I don’t think the software yet supports exactly what you want. You can change the CAM_SLEW_LIMIT and JS_CAM_TILT_STEP parameters to change the speed at which the tilt servo channel output changes.
We could set up the same sort of thing on the other servo channels so that you can use the camera channel for it’s intended purpose. Is this what you want, or did you want analog speed control like a joystick for the input to the gripper?
Analog speed control thru the joystick would be something that would definitely enhance the smoothness of operation in the future. I had suspected the software may not support what I had wanted to do but at the moment using the camera channel will do.
I tried to fin the CAM_SLEW_LIMIT in the parameters but couldn’t find it. any ideas? i adjusted thestep parameters and that has given me better control but still way too fast for the amount of travel required on the ball screw so the actuator is way to fast. You mentioned being able to set the same thing up on another channel so the cam channel can still operate as it normally does. Not quite sure how to do that.
What version of ArduSub are you using (needs to be 3.5), it will let you know in the ‘Frame’ section on the Summary page. You can find the CAM_SLEW_LIMIT parameter if you search for it by name.
We won’t be able to set this up on another channel right now, it’s not in the software.
I am working with a local Sheriff’s Dept. to build a Blue 2 and deploy it for Public Safety use. We would really like to include an arm so we can deploy a marker buoy or grab onto items for recovery without having to put a diver in the water. Being able to video the recovery of an item underwater adds to the credibility of the evidence when it goes to Court.
What’s the status of design / testing of the arms discussed in this thread? Is anyone ready for a field test with a County Sheriff Dept. in SW Michigan?
My ROV is nearing water test status, but it’s been on hold for a while due to my house move. The mechanicals are operational, all the electrical pathways are established, the coding isn’t yet in place but that shouldn’t take me long. I’m probably around a month or so out from a dive test.
Sorry Jim, our ROVarm has been put on hold for a couple of months while we have been busy with other projects. I’ll let you know when we are closer to ready with a beta version. Hope that works for you.
Thanks Roy, I appreciate the update and look forward to hearing from you when you are back working on the arm project.
Jim I was going through some videos from a few weeks back and found this:
You can hear me going “faster, faster”.
UOU! it´s really nice and well done
Are you going to use 3D printing for this?
Hi Mike, we are testing different materials and production methods. So far, we have been using a combination of laser cut acrylics and an FDM type 3D printer. However, the results are not good enough. We have now received our CNC machine and an SLS type 3D printer, so we are hoping to be able to test out other materials using these tools. Once we have the results, we’ll update you guys
I’d be very interested to hear how it goes