ROV Thrusters
Posted: Wed Feb 13, 2013 4:27 pm
I am building an ROV for a group project. We need to navigate a ~50lb vehicle at a depth of 40ft in salt water. One caveat is that the vehicle should consist of cheap off-the-shelf parts with minimal need for special tooling. (Long story short, the client would like to see what an "average" but motivated individual could achieve in the way of seaport vandalism).
The communications, electronics, hull design, and all aspects of the vehicle are trivial to complete - except the propulsion system. Something more substantial than a hacked bilge pump will be necessary for the given size and mass. We are looking for better alternatives at the moment. I have researched this topic elsewhere, and I could ask this elsewhere too, but I feel this community may be able to bring something new to the table.
Several (about 6) thrusters will be used for both steering and general propulsion by varying/alternating the output of each. That said, the thrusters will be fixed in position.
Some ideas currently being toyed with and couple points about them:
DC sump pump / AC sump pump + inverter
-output routed through hoses, or
-pump assembly removed and replaced with propeller
-likely to have shaft seals pre-installed
Brushless Outrunner Motor
-requires conformal coating on magnets and windings for corrosion resistance
-high torque
-bearings likely to rust out
Axial flux motor
-Windings located inside hull
-Rotor located outside hull
-shaft runs in acetal+glass ball bearings
-pain in the *** to assemble
Motor assembled inside sealed pipe with magnetic coupling to external prop
-feasible, but probably pushing the simplicity requirement
-stall-prone
Motor located inside hull with thru-wall seals
-possibly a quick-disconnect coupler
-high friction
-wears out quickly
Help is appreciated. I'll post pictures and whatnot as we make progress this summer.
The communications, electronics, hull design, and all aspects of the vehicle are trivial to complete - except the propulsion system. Something more substantial than a hacked bilge pump will be necessary for the given size and mass. We are looking for better alternatives at the moment. I have researched this topic elsewhere, and I could ask this elsewhere too, but I feel this community may be able to bring something new to the table.
Several (about 6) thrusters will be used for both steering and general propulsion by varying/alternating the output of each. That said, the thrusters will be fixed in position.
Some ideas currently being toyed with and couple points about them:
DC sump pump / AC sump pump + inverter
-output routed through hoses, or
-pump assembly removed and replaced with propeller
-likely to have shaft seals pre-installed
Brushless Outrunner Motor
-requires conformal coating on magnets and windings for corrosion resistance
-high torque
-bearings likely to rust out
Axial flux motor
-Windings located inside hull
-Rotor located outside hull
-shaft runs in acetal+glass ball bearings
-pain in the *** to assemble
Motor assembled inside sealed pipe with magnetic coupling to external prop
-feasible, but probably pushing the simplicity requirement
-stall-prone
Motor located inside hull with thru-wall seals
-possibly a quick-disconnect coupler
-high friction
-wears out quickly
Help is appreciated. I'll post pictures and whatnot as we make progress this summer.