Homebuilt ROVs Forum

I was playing around in my head with the idea of attaching a trolling motor powered dredge onto my ROV for an application I have in mind. The trolling motor I have is 32lbs of thrust and I was thinking of just using a standard Y shaped venturi with the trolling motor providing the thrust for the suction. Has anyone ever seen or heard of such a thing? I'd be interested in some objective input as to what kind of suction I would have and any pitfalls. There's no problem with controlling the motor as I have extra outputs on the ROV and plenty of current from it's on board battery for short hoovering bursts.

I just want this as a simple unit, place nozzle over target, hit thrust and in the bag it goes.

I've toyed around with the idea of a dredge, smaller scale using a bilge pump SEEN HERE and the only thing I've found so far is it need a T-Fitting on the discharge end to direct the output to each side. If not the output of the dredge actually acted like a thruster and pushed the Rov around. Other then that I haven't tested it enough to find out any other bad qualities.

Note - The design of mine did change since those pictures, I got rid of the small nozzle and just used 2" pipe all the way (least I think it was 2") it would suck up a golf ball anyway without any problems.

-Steve

Hi Steve;

Do you have any pictures of the new dredge you can post?

Jim

How deep would this bilge pump work without the pressure damaging the seal?? I really like the design of the bigle pump dredger and plan to make one myself. Thanks

I've been down to about 50' without any problems and I have tested the seals on the Mayfair line of pumps down to a simulated depth of about 200' in a pressure chamber and while the seals didn't leak the pressure did cause the seals to put more drag on the motor shafts which increased the amp draw of the motors. My testes can be SEEN HERE without regreasing the seals occasionally I'm not sure if they would be damaged over time though, I haven't done any long term testing.

-Steve

What about trying a air dredge that makes a vacuum by blowing air into a tube and the rising air creates suction?