The underwater vids seem to show the props delivering power in pulses according to the pedaling cadence. Maybe the old concept of an elliptical sprocket would make things more efficient, is what I am thinking..
Hello, if you are aiming at a more continuous thrust, clip pedals are the clue to it. I am very satisfied with having modified one seacycle leg this way. A real improvement concerning efficiency. No more lost power to support the leg's weight, no more risk of a foot slipping off the pedal.
A challenge was to find an easy solution to change to clip pedals - since both pedal arms are threaded the same way.
Porta, I think you're right - it does look that way, and you definitely get the feel of a power stroke and a pause when pedalling.
Hi Clemens! good to hear from you! I have actually put double sided pedals on - plain one sided and clips the other (you can just see the clips in some of the shots if you're quick!) but its rare that we're actually on a long run, or looking for high efficiency - just pootling round the bay here...
This was really just messing about getting to know the little waterproof camera, but the real eye opener for me is the amount of turbulence off the drive legs - it looks like more than from the hulls! I suppose to some extent they are like little tiny hulls pushed way beyond their normal hull speed and generating a load of wave resistance. I wonder if it might be worth fairing them?
I'm seriously considering a complete rebuild from scratch with some simple ply hulls, because the current build is so heavy. with the dart hulls forming keels, and the weight, its extremely difficult to pull up the beach.
We knew we'd been buzzed by a drone when pedalling round the north end of Gigha, this summer, and the footage has shown up on youtube. Great footage of Gigha from about 1:35, pedal boat at 2:14. It was a beautiful day.
After years on working on the super small "wave interference" boat the design completly changed to something completely different except for the size. As I was always stuck to not being able to plane, I optimized the boat for so long, that it only needed a little push for that. The boat ended up to be a hybrid being very easy to build as everything is done in stitch&glue.
Building is already in progress and will reach completion soon.
It looks like Harry Howard has gotten out of the boat building business and is now selling drop in pedal drives using an inflatable Sea Eagle hull.
The prop drive looks like the same one he had been using previously with his Wave Walker boat. It has an internal gearbox using a narrow #35 chain, so no twisting of a chain as is done in the Seacycle or SpinFin.
$835 is a bit pricey, but it is a high quality drive.
The SpinFin, originally built by Bob Stuart, is resuming production. It's now available in two versions: the original model for kayaks and similar boats and a new 14" longer version for cats and deeper draft hulls.
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