Making a 3d-printed Underwater Dive Helmet With A Floating Air Supply

Описание: Try Onshape Pro free. Design in your browser and start building today: https://onshape.pro/HyperspacePirate

In this video I'll show how I built a fiberglass-reinforced 3d-printed Underwater Diving Helmet with a floating air supply. The helmet was designed as one piece but divided up into 4 segments so that it could be printed on my Prusa MK3S 3d printer. The pieces are printed from ABS and joined with fiberglass/epoxy. The ABS plastic has to be flame treated before epoxy is applied, otherwise it won't stick to the plastic (even if the surface is roughed with sandpaper).

Hinges at the very bottom of the helmet attach to 30 lbs of ballast (15lb on either side) provide the helmet with enough negative buoyancy to stay firmly seated on my head and also allow me to walk underwater (just barely). Because the weights are hinged, they dont restrict my range of motion so the helmet is reasonably comfortable underwater.

The air supply is provided by an oilless air compressor pushing about 40 L/min (1.4 CFM) at 1 atmosphere of gauge pressure (which would correspond to a depth of 10m or 33 ft underwater). The compressor is powered from a 12V 35A-h lead acid battery through a 2 kW pure sine wave inverter, and the whole assembly is mounted on a pool floatie (inner tube).

The flowrate from the air compressor is high enough that the air inside the helmet remains cool and dry, so condensation never appears on the windows. There are 3 6" diameter clear acrylic windows, one in the front, and two on the sides, providing a good field of view underwater.

The whole system works well and the compressor doesn't become too hot even at 100% duty cycle, because the compression ratio is never more than 2.0 if I'm staying at a depth less than 10m. The only thing that requires fixingt is the intermittent air outflow. Rather than flowing out continuously, the waste air accumulates and then suddenly discharges every 1-2 seconds, causing a loud and annoying "gurgling" noise.

With some adjustments, I think I can miniaturize the floating air supply and make it very easy to carry around or transport in a car seat. If I can waterproof the battery and inverter, it should be usable in open water.

Battery: 35 Amp Hour 12V Sealed Lead Acid
Inverter: 2kW Pure Sine Wave
Compressor Type: MAC100Q (Oilless), approx. 40 L/min at 2 bar-A
Hose: 1/4" Polyurethane with fittings for 1/4" SAE Flares

STL Files:
https://www.thingiverse.com/thing:730...

Music Used:
Kevin MacLeod - Groove Groove