BlueROV2 heavy installed with Ping360, Ping Echosounder and 2 Omniscan 450FS: one forward and one port.
Deployed today, had a bit of an issue ballasting. Although the ROV is rated for a payload around 1.2kg in water with 4 lumens (per the FAQ), we still found the device to be negatively buoyant when adding the sonar (combined 275g). I found this by the following weights in water: Ping360 175g, Ping Sounder 100g, OS450 -60g (each), OS450 mount 60g (each, per STEP file and volume calculation).
Due to this, it seems we need to add more foam to keep the device neutrally buoyant. If anyone else has found this issue and found a location to add foam, I would love to hear it.
Hi @tritonkeller -
Sorry for the issue! The payload rating can depend on salinity, and may be a bit out of date - sorry for that!
You can add a roof-rack, and buoyancy foam block with a couple of thru-bolts and long washers - this is a decent way to augment the buoyancy where you want it - up top!
The roof rack is a great idea! I figured I was ballparking the buoyancy calculation due to the extra stainless steel bolts and mounts for the sonar that I added, but it’s great to know there’s something to add. I also realized the tech specs might be for the acrylic housing, thus aluminum would reduce the payload capacity significantly.
As for the foam blocks, should I get the foam and machine it down to spec, or would it be a better idea to get the pre-machined blocks you offer? I’ll probably look at making a fairing for the foam as well.
Hi @tritonkeller -
When we’ve done this, we just took one of the rectangular blocks Blue Robotics offers and bolted it directly to the roof rack. The washers are important to spread the clamping force around the foam. Size the block based on how much buoyancy you need, so you don’t have to add weight to compensate and make the overall vehicle more work to haul!