Bionic Broomstick
Finally!
Bionic Broomstick’s First Sail
March 13, 2014
Birch Creek Park, Lake Somerville, Texas
Attending,
Wife Susie, who’s easily amused observing proaphiles in action, came in her own car as there’s
a limit to how long she would be amused.
TheEnemy, new Proa File member who pulled out on the highway behind me as I drove by. What are
the odds, he was coming to the event but timing like that is beyond serendipitous, though a
proa on a trailer is easy to identify and rare.
Kevin Oneil, long time pronaut, surely has more miles on a proa than any other Texan and the
rare distinction of currently owning two proas. Today he brought his elegant and simple
sailing canoe under development.
John Wright, also a long time pronaut, just back from the Everglades Challenge, brought the
hull of his proa under development.
As the weather was relatively cool, in the 30’s the night before consensus was an early splash
wasn’t necessary and I arrived at lake a little after 10:00, TheEnemy following. Rigging boat
is pretty straightforward, it’s been done a few times in the yard. Once the whole group is
assembled, I carry the boat out into the water in the teeth of a 5mph (max) wind. You couldn’t
ask for better conditions for a first sail, winds are very light but fairly consistent. Boat
traffic is moderate (most pontoon boats Susie and I’ve seen in 40 years at this lake).
Hard to get in trouble ghosting along in these conditions. The boat will go to windward, has a
little bit of lee helm. Putting the front rudder down not quite halfway seems to be best.
Moving the front rudder off neutral to put some camber in the hull doesn’t seem to make a lot
of difference. Shunting is simple in these conditions, put the front rudder down, pull the
continuous sheet in to the other side and the boat changes direction, partially raise the
front rudder. Rudders work surprisingly well, stay where placed up and down, easy to operate
Tillers are alright, push pull isn’t automatic to me but it’s easy to see when you’ve zigged
instead of zagged (Kevin had the same issue when he sailed the boat). Sail shape is somewhere
between terrible and horrible. Some more wind would help the sail take some initial set and
there’s obviosly some more work to do in adjusting the tension and location of the boom
bridle. Even more work needs to be done on the boom rigging to make roller furling around the
boom a practical reality. According to the GPS the moving average on the first sail was 2.5mph
and the maximum speed was 3.8 mph. In these conditions it’s easy to play around and ‘cleating’
the sheet with your foot allows a hand on each tiller to play around with enhanced
maneuverability and crabbing to windward or leeward. I suspect that such antics in some real
wind would have potential consequences.
After I’d sailed the boat Kevin took it out for a sail and seemed happy with it. He did get
carried away once with maneuvering the front rudder and moved it far enough off axis that joint
opened up and the assembly moved past the stop on the hull and floated up a a couple of inches
but was still operational.
Overall I was very pleased with the first sail. Nothing broke except the tabs on the bottom of
the rudder assemblies, which broke off on the drive up to the lake allowing assemblies to slip
down in thier sockets. Not a problem on the water, but required tying up on the trailer.
Trailering was just adequate. HF trailer with a bolted on tongue extension and 8” wheels won’t
ever be super road worthy but worked better on the way home with weights biased forward just a
bit.
BB was originally conceived to trial out some ideas before implementing them on a more
substantial boat, Nomad. I’m convinced the end rudders are a workable solution and will
definitely go that way on the next boat. Originally the other area of investigation was to be
between the cambered panel staysail currently on BB and a biaxial “Bolger” type sail that I’ve
had quite a bit of experience with both in theory and practice. The biaxial sail has fallen to
the wayside since if either one works, they both work and the cambered panel sail has a few
inherent advantages in handling that are hard to ignore.
New to the mix while I’ve been waiting for my shoulder to heal is the wingsail. Peter W’s
circular cam and Elkaim’s doctoral thesis that included a segment on low Reynolds number
wingsails have conspired to whisper in my ear “there’s a better way”. BB’s almost the perfect
vehicle to trial out such an approach and see which works better. It will be a while before we
know, there’s been a lot of deferred work around the house while my shoulder healed, but soon.
The cam assembly’s made, tailplane is almost done and the rest is underway.
I appreciate the comments, ideas and criticism received on the forum that have helped develop
and direct the concepts to this point. Such a thing has not always existed and I think it is
special.
More later,
Cheers,
Skip
A little snippet of ghosting along
http://youtu.be/C0CCgWB51a8
Comment on the first sail
http://youtu.be/YZyFAbylHo8
Congratulations Skip!
One of the pictures, are you telling me that you can lift the whole thing and carry it to the water, even with you “just healed” shoulder?!!
I am jealous…
Laurent
“Just healed” took damn near a year 😉
Boat doesn’t weigh that much and it’s not like I’m trying to lift it over my head.
Skip
Laurent, you should know that when Skip says something doesn’t weigh that much, he means it’s somewhere between feathery light and filled with helium. 😊
I had a really nice day of sailing and messing about. Bionic Broomstick II was perhaps the most successful first day of proa sailing I’ve ever seen. The boat worked great, steered great, shunted very fast. To shunt you let the sheet go, drop the new rudder, sheet in the new sheet and raise the old rudder. Very fast, and you never move. Very comfortable to sail.
The wind was light, 5-10 all day. In those conditions the sail was fine. The boat zipped along fine, and ‘tacked through’ about 100 degrees, I’d say. In more wind there might be some trouble with leading edge tension, but since Skip’s working on a wing anyway it’s not a big deal.
My little canoe was a mixed success. It’s very comfortable to sail. I like the shape of the batwing sail a lot, but the polytarp material is way too heavy and the shape is bad. I stuck some chine runners on to see how they would work. They were ok. Between the terrible sail shape and the crappy chine runners and the tiny rudder I could barely sail above a beam reach. In playing about I found that if I stuck the paddle down behind the chine runners a la Dylan Winter in a duck punt I could get to windward much better, but it’s a kludge. The boat needs a bigger board and a bigger rudder and a better sail. But, overall I’m really happy with it.
So, nice day of messing about! Good weather, nice boats, good conversation, got to see some of the bits and bobs for Skip’s new rig, which I don’t understand but which looks really cool. Had a good time. Thanks for calling me!
Well done Skip, sounds like a great sail, and Laurent was positively gushing. As I expected your well thought out and engineered concept just simply worked. Really looking forward to further reports but would just like a few more pics
Fantastic
Tink
Here’s some that I’ve access to at the moment, others are at office, also am having trouble digging the track out of my GPS. Next week.
Skip
It really was a lovely day, for a first sail. Enough wind to move, not enough wind to break anything. I learned a lot (since I haven’t sailed in years) and everyone had fun, so there is that! Now, I’m probably going to build myself a dinghy for myself, so I can sail more often. I can’t wait to see your wing sail when it is finished, Skip!
Finally!
Bionic Broomstick’s First Sail
March 13, 2014
Very cool, Skip! Hey, how come you have that Bruce foil ama set vertical? 😉
I’m more impressed than I can say to hear that all the systems on the boat worked, first day. That’s outstanding. A question, since I obviously missed it (along with the Bruce foil!): How are you locking the forward rudder?
New to the mix while I’ve been waiting for my shoulder to heal is the wingsail. Peter W’s
circular cam and Elkaim’s doctoral thesis that included a segment on low Reynolds number
wingsails have conspired to whisper in my ear “there’s a better way”. BB’s almost the perfect
vehicle to trial out such an approach and see which works better. It will be a while before we
know, there’s been a lot of deferred work around the house while my shoulder healed, but soon.
The cam assembly’s made, tailplane is almost done and the rest is underway
If it helps, AYRS’ Catalyst is publishing a neater, (slightly) more coherent article I wrote for building quick and dirty wingsails. Not restricted to tail booms or automatic controls, it is more basic than that and should serve to build wings from 25—to perhaps 100—120 sq ft. Much of the contents are here on Proa File, but the Catalyst article pulls it together. Very quick, very dirty build (inexpensive, not ugly!), also includes thoughts on upgrades to bigger, stronger versions. Will be in the April catalyst, I believe.
Dave
Super cool! Thanks for sharing, Skip!
And congrats on a successful test of a LOT of new-to-you systems. Most impressive.
Chris
Very cool, Skip! Hey, how come you have that Bruce foil ama set vertical? 😉
I’m more impressed than I can say to hear that all the systems on the boat worked, first day. That’s outstanding. A question, since I obviously missed it (along with the Bruce foil!): How are you locking the forward rudder?
Dave
Technically it’s not a Bruce foil but a Floil (buoyant foil). Bruce foils are primarily for the fast and furious, I’m more into the quick and easy. Forward rudder locks by clipping the tiller (1” schedule 20 PVC) into a pole clip fastened to the side of the seat.
Look forward to the article on building wingsails.
Cheers,
Skip
The Broomstick flies on it’s first outing! Congratulations on the excellent first sail, and thanks for the excellent write up!
The boat will go to windward, has a little bit of lee helm. Putting the front rudder down not quite halfway seems to be best.
This is a fascinating contrast between the maiden sails of the Bionic Broomstick and Crazy Russian’s proa. I was hoping to hear more from Vlad (Crazy Russian) about his opinions on why the boat was so hard-mouthed but I haven’t found anything beyond this post at the Watertribe forum. The similarities between the two boats are obvious, both small single handers, single sail, rudders on the bows!
The big differences: Broomstick CE more centered, thanks to the balanced area of the staysail, and also features a large, buoyant “floil” to windward.
The big differences: Broomstick CE more centered, thanks to the balanced area of the staysail, and also features a large, buoyant “floil” to windward.
There are some other major differences, Crazy Russian was loaded for expedition (????#) and had twice the sail area +/- in a real sail. Also don’t know what the weather/wind conditions were at the start of the EC.
Just because the first outing was trouble free doesn’t mean that there aren’t some real demons lurking in the wings 😉 Particularly in more wind.
I greatly admire Crazy Russian and still consider him an indomitable spirit, turns out he was a wise indomitable spirit. The EC is still hard on proas ;-(
More later but I’m starting to have some real opinions about end rudders and it will be interesting to see how things work out in the next iteration (or two).
Skip
More later but I’m starting to have some real opinions about end rudders…..
Skip
I’ll be interested to hear those.
Congrats on your efforts so far and I’m really looking forward to seeing your wing rig!
Mal.
I’ll be interested to hear those.
Mal.
Me three (me too + 1).
I don’t believe it is a rudder balance thing. I had enough balance built into design. I light wind, while i was sitting on the main hull and kept outrigger just kissing the water she would go in straight line for minutes. However as soon as i move to the trampoline, pull would show up.
Vlad’s note about the differences between the unloaded ama with a balanced helm versus loaded (him on trampoline, weather helm bad) caught my eye. If rudder states are the same in both conditions, then perhaps excessive aka length, in combination with ama drag should be considered. If I recall correctly, Simba/Pacific Bee’s current owner shortened aka length (after careful deliberation) and the boat performed better.
Seems that the ideal amount of righting moment needed for balanced helm is a moving target dependent on conditions. With a fixed aka length the boat has a narrow optimal set of conditions - and if the wind is higher or lower either the righting moment will be inadequate or the ama drag will be much higher. Controllable water ballast in the ama is one approach to mitigate this.
—
Bill in Ottawa