Tuesday, November 6, 2018

A Steerable Airboat

The back end of AMOS now has a pair of air rudders situated behind the propeller fan and cage, driven by the servo motor described last week:


Initially the pivot rods used on both rudders were epoxied on, but one of the first tests of the rudders that I did (with the fan blasting at maximum power) caused the epoxy to crack off the left rudder and send it flying. So instead I drilled some holes near one edge of the aluminum sheet and threaded the rods through those. That seemed to be much stronger than the epoxied connection, although the epoxy on the right rudder survived so  I just left it.

The software was modified a bit to allow for manual control of the propeller power and rudder angle. You can see the results below in this video that my daughter Bexie shot and edited:



With our pool semi-drained for the winter, I needed to be careful not to get the boat moving too fast towards the walls. A couple of times it did collide with the walls, resulting in a small crack to one of the inner rings of the back cage.

Currently I'm editing the navigation and control software to work with the propeller / air rudder combo. It would be good to have a chance to test this out in the shallow cove at Woolastook, maybe sometime next week.

2 comments:

  1. Very cool Murray. What ratio of the energy used by the boat can the solar provide when in motion?

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    1. Good question, it depends a bit on the speed. At the maximum speed, the boat consumes ~ 200W of power, so the 100W solar panel would provide at most half of that. I have plans to add some circuitry and software for measuring both the charging current as well as the load current, so that should help to better quantify how much run time is allowed or charging time is required.

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