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Re: [PSUBS-MAILIST] Minn Kota's



In a message dated 7/2/2009 8:57:12 P.M. Pacific Daylight Time, brenthartwig@hotmail.com writes:
I'm seriously considering using my side thrusters only in a vertical position, unless there is an emergency, such as I'm in a nasty current, or my stern thrusters are not operable.  When in transit I might rotate the side thrusters so there is less hydrodynamic drag on them. Then once at the dive site lock them in the vertical position.
Hi Brent. With the electric actuators I'm using to control the position of the side dive plane/motor mount, I can set the thrusters at vertical, and using reverse, pull the sub down. The "wing" dive planes in the vertical position act as "brakes".
They rotate through a 120 degree arc from vertical to angled 30 degrees down. I expect to use the side thrusters as the primary motors when moving slowly along observing the bottom through the large main window, while the two rear thrusters will be used for higher speed travel such as transit through the water or during survey of a larger open area. I'm looking forward to finding out how fast the sub will go with all four thrusters at full power, but don't expect to use that setting very often. Maybe for a high speed chase of a Humboldt squid ( Git a Kraken? ) or to keep up with a whale.
The actuators are operated with a simple "rocker" switch, making the steering and dive plane controls very compact. Able to fit on a small "controls box" along with the speed controller dials, and this box will be able to be moved around inside the sub, and also taken up through the hatch so driving the sub while standing outside on the deck like maneuvering around in the harbor, parking at the dock. 
   The nice thing about using the electric actuators as positioners for rudders and dive planes is they stay where you set them. The bad thing is...they stay where you set them. I had originally planned on using air or hydraulic cylinders for these three controls, with a fail safe mode where the rudder centers itself, and the dive planes go to vertical if the system fails.
I traded that option for the simpler controls associated with the electric actuator approach. No air or hydraulic lines,pumps, valves, tanks, gages, etc. Just a small electrical thru-hull with the motor wires and actuator wires, all sealed in with epoxy, and just a rocker switch and forward/reverse speed dial. Doesn't get much simpler than that. Should a problem develop, replacement of any of the individual components will take just minutes, and in the case of a leak at the thru-hull, pull the wires off the spade connectors and close the ball valve the wires go through. Keeping it simple is one of my primary design considerations. The fewer parts, the easier to maintain, less chance of component failure, and actually cheaper to build too!
Frank D.