Phish(TM) as Diver Propulsion Vehicle

Fabrication blog

Hot tub test of the TRE. It starts to get more interesting around 2:40 click here to go that starting point), as I turned up the power. Unfortunately, the isolation pod cracked around the drive-shaft! Darn it. An opaque plastic would be tougher, less brittle, than this translucent plastic. Building a Phish around an inexpensive "frameless" induction motor would also make sense, using lead-acid paste batteries.

The Torque Reaction Engine (TRE) operates again! The first part of this video tells me that the acceleration/deceleration curve needs to be adjusted, so that it is smoother on both sides of the change. The second part, about 30 seconds in, shows that even this initial setting works!

The revised battery pack arrived! I'm really excited. It fits the motor well, has ventilation, is clearly strong enough (I wasn't sure about that), and the slots for the electronics are suitable (they are on the back side). Now, assembly won't involve a complicated step involving resin. Onward!

Here's the battery pack, which ruptured into four pieces. The batteries expanded and ruptured the battery frame. This was not a hydrogen explosion. A hydrogen explosion probably would not have broken the battery frame and, if it did, not into four similarly sized pieces. The four pieces indicate the frame was experiencing uniform strain, as would have been caused by battery expansion. Also, none of the batteries ruptured. It's all a learning experience. Batteries aren't a moving part, but they are still complex.

This was the first test of the DPV, operating, in water. The Phish had a thermal shut-off that was only 2 degrees warmer than the hot tub, so it was shutting off really quickly. I put the Phish(TM) in a refrigerator, to cool it off and make sure it wouldn't keep on triggering. Later that day, I took it to a pool. After about 1 minute, as I increased the power draw, the batteries expanded, forcefully fracturing the rigid battery pack into four pieces. Rats! I need to redesign the battery pack to give the batteries room to expand and contract. In case you are wondering, the fluke was not set to generate any thrust (I can tighten the flexure, to give it thrust).

2018-07-21 displacement test for the DPV, with battery pack and motor, pink clip used to hold air tubes

First air test for the DPV

Turning on power to the motor in the DPV.

A Phish wears a swim suit. Thanks to Susan Swolgard, for her work making the swim suit. Displacement bags, inside the suit, will be inflated, to provide flotation.

Test of fluke and central hull beam.

Central hull beam, pod mount, motor pod, and fluke.

3D print of the motor isolation pod, the motor, and the battery pack, which encircles the motor.

Fluke layers and fluke bearing.

It started with a 3D model.