ROV Project "Bumblebee"

[Cabbagehead]

Hi there,

Many years ago I posted my initial ROV design on this forum and received some very useful feedback. Since then I've gone and done almost 3 years of an engineering degree and it's certainly helped my design capabilities! I've come back with my second design, affectionately called Bumblebee for obvious reasons when you see it, and I actually plan to make this one.

Render Motors Out.png (492.59 KiB) Viewed 3682 times

Render Motors Down.png (527.2 KiB) Viewed 3682 times

Render Rear.png (450.94 KiB) Viewed 3682 times

The ROV comprises of:

• 140mm diameter 5.4mm wall PVC pipe as the pressure vessel, with a 3mm acrylic dome as the front cap and a 10mm thick nylon rear cap
  3 20W-equivalent LED lights mounted outside the main pressure vessel
  4 810KV motors, mounted on servos so that they can convert between horizontal and vertical motion
  Raspberry Pi 3B control board
  2 axis controlled raspberry pi camera
  4s LiPo battery(s), not entirely sure about capacity yet
  CAT5 cable tether to network the ground station to the ROV
  60m target max. depth

The most ambitious part of this project is definitely the tilting motors, I've seen a few people here try it but I haven't really seen much in the way of results. If you do have experience with tilting motor ROVs it'd be great to hear from you! I'm open to suggestions and discussion about this design. It'll likely progress fairly slowly due to pesky exams and a degree taking up my time, but I hope to make a substantial start on construction by the end of this year.

I've added a few renders I've made of my design to give you an idea of how it's going to be laid out.

[MarcoMota]

Neat design! How are you planning to water proof the servos?

I tried to make a servo solution, but it's really difficult to waterproof the servos and guarantee it will keep waterproof for a long time.

[Cabbagehead]

My plan with the servos is to fill them with oil and then possibly glue along the seams using dichloromethane or some other solvent/glue. I seem to remember reading somewhere on here that this method works relatively well at keeping water out as any space for water to get in is already filled with oil. If this isn't the case I'd be very happy to hear other suggestions.

As the servos are pretty cheap it may be a case of having to replace them every now and again, which wouldn't be the end of the world. If I can find a long term waterproofing solution though I'll absolutely use that!