The concept for ROVER 1 began with a home made drop camera I purchased used. I knew this housing worked well down to 300' and my plan was to convert it into a towable fish I could drag behind my boat. I liked the housing but had no way to control it, other than the tether. I was working on a fin design for the housing when I became involved in the Search for Clarence Holmes.
After my first trip to Laurel River Lake, I knew we needed more than a drop cam so I started thinking about how I could build a compact, robust ROV that we could move in and around the forest of trees we needed to explore. Ideally a unit with no tether would be best but that is way too far out of the budget so I began thinking about “flying” the drop cam and Rover 1 started to take shape. The Housing is 5” PVC pipe, 12” long. It uses compression type clamps to attach the end caps.
The end caps are 3/4” x 6” Plexiglas with an o-ring seal. There are 4 marine clamps that hold each end cap in place.
The o-ring is held in place by a free floating inner ring that is made by cutting a short section out of a piece of the 5” pipe.
O rings are available from Grainger's part # 1KML8 (5 pack -429 buna -N 70)
The thruster covers/mounts are made from hard plastic drinking cups. I drilled the ends to line up with the Open ROV motor mounting bracket and cut the sides and wire chase away with a dremmell tool. The key was laying out the center lines 120 deg. apart and finding the right width for strength / water flow. I drilled the mounting holes and then slotted one hole on each cover to allow for mounting adjustments where the thruster cover mounts to the body.
Rather than drill and screw the thrusters into the main housing, I used another piece of the 5” PVC and cut a section out so that it would fit over/around the main housing as a mounting bracket.
Internally I used a UPS power supply style battery for power. I placed this on it's side and Velcro the control boards to the other side. This put the control boards at the highest interior portion of the housing should there be the inevitable leak. Besides high amp hours, the other benefit of the large battery is added weight to offset the buoyancy of the main body.
In the front of the housing I utilized the existing design for the camera mount. A pair of pieces of the 5” pipe serve as retainers and another piece of pipe fits in nicely when inverted. Note the counter cut on the sides of inverted mounting pad . This allows the pad to remain in place if the unit is inverted.
Once I had everything assembled, I found that the battery was sitting too far to the rear. I shortened the camera mount bracket and moved the battery more to the nose of the body.
The tub test revealed that I needed about one more pound of weight. Rather than a 1 pound single weight which was actually 2 oz too heavy, I screwed some fishing weights
onto the motor mounting ring. By leaving the mounting ring a friction fit on the body, I can slide it toward the nose or tail to get the trim right where I need it. If I make any changes to the unit like adding an external camera like a GoPro, I can add or subtract the fishing weights to re-trim the unit.
The pool test went well but I do have some leak issues with water migrating through the wire bundle. A little properly placed Aquaseal here and there should take care of that.
Next step is some deeper water and extended submersion trials.