No I haven’t done anything more on the Ultralight. Now that I’m back in Sydney and catching up on projects that have fallen behind, i do hope to be able to get back to this.

While working on the Sienna (solar boat) I did experiment with making the foil larger on the Cruise 2 (to help with steering) but the interesting thing was that I used some foam sheet that is typically used for signs, such as a real estate sign. Its about 5mm thick and curves nicely. I used some Purbond polyurethane foaming glue It produces a foam that seems to have similar properties to the foam sheets I used and it can be sanded and shaped easily. So you might want to check that out as a way of making the foil.

As to the bottom orange bracket, its needed to stop the motor from sliding updwards/forwards when you pull on the cord to raise the motor when coming into the beach. But whatever you use as a cav plate/foil would prevent this effect too.

Another option for the foil is that I have a foil from a damaged 801 and you might be able to use that for your experiments. Let me know if you’d like to use it.

Cheers

Chris

My dad and I are planning to make a cav plate for my new Ultralight 403 (he reckons we should just do that before mucking around making a foil), did you ever get around to doing more work on yours or designing it?

We have a sheet of 2mm aluminium that we’re theoretically going to cut to shape and glue to the shaft, with some other attachment points somewhere to hold it in place.

I can envision having a hole through it that feeds over the shaft, and having the plate rest on the lower orange adjustable bracket. Given that when the motor is mounted, it hangs from the upper orange bracket, what is the lower orange bracket actually for? Does it do anything?

Your theory makes sense to me as far as power to the prop is concerned. That is, there would be no difference in the power being delivered to the prop.

There could be a difference, probably small, in electrical and drivetrain losses to get to this point. We could speculate that the double reduction of the 801 would introduce more losses than the single reduction of the Cruise. On the other hand, the lower voltage of the Cruise would require higher currents and so there may be more energy lost to heat, perhaps balancing the effect of the reduction.

In practise it would probably be very difficult to measure the difference.

Cheers

Chris

I suggest you use a bicycle locking cable that can be passed through the handle of the battery and locked to the boat and also locked to the frame of the 1003. On the 1003 there is a hole in the frame where the battery attaches that can be used for securing to the battery and to the boat.

Cheers

Chris

is there a way to lock down the battery on the 1003 so it can not be stolen ?

Thanks,

Jules

Great video! I love your boat—it is a nice design and slips through the water really easily. Easy to put on your car and looks great too. When are you going to add solar panels to the bimini?

Thanks for the news.

Cheers

Chris

Tom Sawyer

Thanks for the update on the Ultralight trials. Do you have some photos and other details about the foil and the mounting? I’d be interested and I’m sure others would. We could put up a new blog entry about your project.

I haven’t made further progress on the Hobie Wave installation and it could be helpful to see what you have done.

Cheers

Chris