Summer Accomplishments & Presentations

First, we're at Seattle Mini MakerFaire (https://www.facebook.com/events/215651449157117/?event_time_id=215651455823783) this weekend, in Maker Alley! If you're there, please come by and say hi!

Second, I gave two talks this summer -- a ten minute one at MakerFaire Bay Area and a longer one at Toorcamp. I'm still working on getting video of both -- in the meantime, here are my slides:

On the hardware front, we've gotten the wing molds fabricated and will shortly begin pulling some test parts. We've also put together a full set of cut files for the hull of the Microtransat boat.

We also added compasses to the wing sails in order to allow us to estimate the wind direction without additional hardware. This simplifies the boat and removes one more system (wind vanes) from the critical path.

Most of this summer's progress has been in the software realm -- we've spec'd out and written most of the necessary modules for the Microtransat boat. We're adding them in to the little boat's control system one at a time to test how they work in practice, and sailing them in Lake Washington when our schedules and good wind line up. Since the boat is a bit on the heavy side, it's not a particularly good sailor and really needs about 10 knots of wind before it performs decently. That's good enough for software testing, however.

We're looking forward to additional sail testing this afternoon, and we're also exploring resurrecting TSV Disputed Right of Way for creating a database of tagged images of the marine environment around Puget Sound.

A slight change of plans and a long overdue update

 Eastbound (green) and westbound (red) Microtransat courses

Eastbound (green) and westbound (red) Microtransat courses

Last fall, we successfully tested our wing schooner sailing system on a one meter scale in Seattle's Greenlake. This test (on a tether) has given us the confidence in the basic soundness of our concept to proceed with the design and construction of our Microtransat Challenge boat.

This boat will be the maximum length (2.4m) with a displacement of approximately 75 kg, about half of which will be ballast.

The wingsail/masts are similar in concept to our wingschooner demonstrator, but the bearings are set into the sail rather than the hull in order to have water drain away from the bearings rather than pooling on top of them.

First, the slight change of plans. We've decided to compete in the Microtransat Challenge in preparation for circumnavigation. Since Microtransat boats are limited to 2.4m (8 ft) and the task is crossing the North Atlantic rather than circumnavigation, the team determined that we could build a competitive boat without having to raise outside money.

The Microtransat has run every year since 2010, but is sufficiently challenging that no team has yet completed either the east bound or the west bound race. The rules are relatively simple -- vessels may be up to 2.4m long, must be self-guided with enough precision to hit a pre-selected point on the finish line, and must be propelled by the wind.

 Our wing schooner demonstrator afloat in Greenlake.

Our wing schooner demonstrator afloat in Greenlake.

 Microtransat Challenge design

Microtransat Challenge design

Currently, we're working on building the wings and completing the software. More to come on those subjects and the design process for this boat in future installments, which should hopefully come at less extreme intervals.

Successful control!

We put larger (and lighter) tails on the wings as well as a proper windvane and got back in the water on Oct 22, again at Greenlake. We got the boat to reach, run, and even sail to windward under some measure of steering control. We still have the leash on it because the control is still dodgy, and the range is not wonderful. 

The weather has conclusively turned here in Seattle (it snowed both today and Friday), so we're going to spend our time working on software and planning for the around the world boat and our fundraiser to pay for it. 

Sail Testing

There was more wind than predicted this afternoon, so we had the opportunity to get the sail boat in the water for our first successful sailing test! 

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The boat sailed under its own power, responded to remote commands, and we successfully retrieved it. However, it's going to take a lot more practice and some modification to get good, predictable control of the boat.

There are a couple of reasons for this. First, it's just a plain hard boat to steer. The steering response is quite different from any other boat. Second, the wings have too much inertia relative to the size of the tails, which makes them hard to control in relatively light and changeable winds like we had today. Our next steps will be printing some bigger tails (moar powah!) and moving up our plans for a third wing revision. 

In other news, we're looking at MOOS-IvP for building the next software generation, and it looks good.