Building your own scooter?

[OTF]

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.

 

[Cthippo]

Only thinking about this because I have one in the shop I moved tonight to get at a door, but what about a decomissioned fire extinguisher or SCUBA bottle for a housing?

 

[PR_SMITH]

I have just started thinking about a DIY DPV; this guy has built one from a trolling motor: diy dive scooter - Google Suche

I don't like the toggle on/off switch, seems kinda sketchy, as mentioned by someone else. I don't suppose the shaft seal on the motor would be sufficent for any real depth. The video shows him about 6" underwater. Another issue is the lack of a clutch of the motor, and not much shroud; could lead to fingers becoming chum.

I like the idea of getting a Faralon and converting it to power tool batteries.

 

[lucca brassi]

my thoughts stopped at rpm reduction : Are DPV noisy ?

 

[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

 

[prid1279]

Aluminium cylinders that have failed testing make a cheap basis for housings. Require a lot of machining to reduce weight and some time spent learning about o rings and seals but can be very dependable

 

[Eric Sedletzky]

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.

 

[The Ruttmeister]

A fiberglass hull made over a suitable form isn't difficult... The challenge is predicting the strength.

That said, it wouldn't be difficult to make a hull, plug it and drop it to some depth well below your planned max depth to test the strength.

I would have to go look up how thick the fiberglass needs to be, but I know variably due to hand laying is an issue.

I saw a hobby carbon tube winding machine at a makerfaire years ago.

 

[Gone for diving]

I saw a hobby carbon tube winding machine at a makerfaire years ago.

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

 

[The Ruttmeister]

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

A bit more difficult to proof test that kind of thing