Attempt # 4 - 2019

The fourth attempt is scheduled for the fall of 2019. See The Boat page for the re-designed drivetrain. More pictures will be posted as soon as possible.

As you watch v4's progress on the tracking page, make sure to chime in on the forum. It's fun to hear from you and I encourage questions and discussion. This means YOU!

New Hull

v3's surfboard hull was recovered, but there was some fiberglass delamination that occurred before it went to sea and I thought it would be better to start over. The problem arose when I left the boat on my back porch in 95F heat. It started to balloon and each day the space expanded. I don't anticipate that happening when the boat is in the water. It didn't seem to affect the voyage, but why not start fresh?

VID_20190730_161455105.mp4

New Drivetrain

The mast/sail is rotated by connecting it to a motor via gears. In the v3 design, it was a pinion gear against the mast gear. It looked like that connection failed, though it didn't completely shear.

Regardless, this new design should be much more robust. Sprockets and chain greatly increase the bearing surface. The motor is a small 6V 6rpm worm-gear, so it can't back-drive. It's under the small sprocket at the top of the picture.

The second small sprocket on the bottom of the picture connects to a 10-turn potentiometer. Since the gearing is 48-to-16, the pot will turn 4 times for each mast revolution.

The mast adjusts at roughly 1 rpm (since it is actually driven with 5 volts).

Code

There were almost no code changes between v3 and v4. I did add the ability to restart the onboard computer with a remote command, just in case.

If you want to take a look at the code, it's all here: github.com/cgorton1313/gortobot

The grand total is about 2000 lines of code.

Electrical

And for the electrical engineers, here's the schematic:

You can see that the two battery banks are independently charged, and whichever has a higher voltage will run the computer, satcom, etc. But, only bank 2 will run the motor driver. That is to prevent brown-outs and restarts of the computer should the motor compartment flood or otherwise short out. (That happened to v2, and it made for some desperate last attempts to stop the mast motor from turning on...)