Building your own scooter?

[Gone for diving]

First of all - be VERY careful about safety with these, a scooter switch stuck in the "on" position can be extremely dangerous, dragging a diver up or down uncontrolled. Carefully consider a very reliable switch mechanism, or some sort of redundant killswitch. Runaway scooters can and do bend people.

If I were going to DIY a kickass scooter on a budget I would poke around for a GOOD deal on an old (dead?) past generation scooter, one of the large ones meant for lead acid batteries like a Farallon. That provides a cheap well-engineered housing and prop. I would replace the electronics with a large modern brushless motor, ESC, and LiFePO4 batteries with onboard BMS (or power tool batteries). Similar setup to an ebike. Make sure any penetrations, shaft seals, and o-rings are replaced and reliable.

Marinizing a big brushless motor and running it wet is also an option, and eliminates the shaft seal. Wet running brushless motors have a lot of advantages, though encapsulating the rotor and stator properly is nontrivial. Bearings, shafts, and hardware need to be swapped for corrosion resistant materials.

Original motor but has new controls, 30 ah batteries lithium iron batteries
And capacity and wattmeter,
Steel homemade prop.
Trick is to shift battery weight as far forward as possible

 

[Eric Sedletzky]

If I recall correctly there was as submersible built like that a while ago.

Right, for 10,000 ft., not 130’

 

[OTF]

Original motor but has new controls, 30 ah batteries lithium iron batteries
And capacity and wattmeter,
Steel homemade prop.
Trick is to shift battery weight as far forward as possible

That's a sexy beast. What kind of run time do you get? How powerful is that huge LED? Did you make that nice little display housing as well? Are those wirenuts in there lol?

 

[Gone for diving]

That's a sexy beast. What kind of run time do you get? How powerful is that huge LED? Did you make that nice little display housing as well? Are those wirenuts in there lol?

Sorry no wire nuts I assume you mean the white things? That's heat shrink to contain wires going into the cells, and RC X60 plugs

2 50watt led cob chips, (very large flood pattern), but the driver is set way down, even on the setting now it's way to bright, for our dirty water. 10-15 watts I think.


Yes I made the display, I have milled one and I have tig welded one, either way it's a bunch of work,

Run time is like anything,
depending on your speed, etc
But I get 3-4 dives @ .75 -1 hr. Before charging.

 

[prid1279]

What about casting a hull out of fiberglass?
I have a lot of fiberglass experience - making moulds and laying up parts.
It would not be hard to design and build a torpedo shaped hull that could withstand 130 fsw.

Sounds like you have the experience, would be a really cool project.

 

[Eastwest]

I have built many over the years . The hull was tricky with good learning mistakes . Your hull can be developed from a aluminum propane tank or similar pressure vessel . Trolling motors have worked fine and been at 150 feet many times . Just bought a new deca deep cycle battery 55 amp hour for the 55 pound thruster which gives you a one hour burn time

 

[Eastwest]

I have built many over the years . The hull was tricky with good learning mistakes . Your hull can be developed from a aluminum propane tank or similar pressure vessel . Trolling motors have worked fine and been at 150 feet many times . Just bought a new deca deep cycle battery 55 amp hour for the 55 pound thruster which gives you a one hour burn time

 

[BoundForElsewhere]

Please make sure you put a couple of these at the front...