Thanks for the practical advice in how to glass one piece things - I am just approaching this point now and the need for practicality is never greater.
I have cut the hull of ZBF and it is almost ready for glassing - see attached pics. Max diameter is 40mm.
I have sorted out the sheeting and rudder drive - sadly the sheer purity of the design have been vitiated - I have adopted a Vertical Hull Extension in the location of the mast foot which houses concentric tiller and sheet drives too (and the aerial)
And the switch wires - unless I regain some of the lambent purity and use a reed switch
Pics attached of the cutting process using my vertical foam cutter - In fact I made two hulls because the “squareness” of the first was not quite as planned
see next post for the outcome
andrew
Havin cut it to a square profile I took off the edges at 45deg and then rounded with a long replaceable knife blade - then minimal sanding took to to near circular
Before glassing I will make the vertical bits and mast tube - rudder is now hung gary-style on a rearward ruddder bumkin and driven by pullpull cables.
I have been guilty of the offence of conventional thinking - the ZBF I am creating is merely a tickling of the edges of design.
Peccavi
Whille using a corkscrew t’other night I was musing on the sages, starting with Archimedes (whose two Laws* are immutable), and going on to commune with Savonius , who I know little about other than his perceptive vertical axis wind turbines.
*second law- “When a body is wholly or partially immersed in a fluid - the phone rings”
For fear of forfeiting my patent rights and stirring up sea-lawyers and rule-readers I can reveal nothing of the radical design that is being built as a result at the stealth footy facility with its expansive hydrodynamic test tanks.
Nothing except that the sails get around a bit, and it may be that the second
channel of control is either not needed or unconventional.
Fortunately this concept, which could not be accused of conservatism, can be readily built and tried, so I will.
Now if I can combine this radical idea with the ZBF and the trained cuttlefish
I remember a rotary winged control liner from the beloved Aeromodeller (with two 'L’s as it should be). But that rotated backwards to create lift. Which could be awkward, in that if turned vertically it would create a sideways force. Sideways as compared to the direction of travel… Uff-da.
If we are talking Flettner rotor that would be very interesting, but not entirely legal, since the rotor would need a motor for it’s powered rotation to make it work. I don’t know if the Footy rules allow that, though it doesn’t appear to be specifically prohibited.
Flettner, Flettner? That would be illegal if powered, and I would NEVER propound anything illegal*
*unless it was interesting.
I have been wondering if Savonius was the man who gave his name to french soap (that rare commodity), but no, he was the gent I ment. Not too literally, of course, but generically and figuratively the VAWT family
None of my projects are likely to get much progress while festivities are happening as things have their own imperatives at this time of year - but hope to get the ZBF glassed if there is a mild night (epoxy). I can also get the buoyancy compensator carved, since I can now imagine it in the foam.
I’m gutted that the purity and elegance of my rudder/roll compensator has been shelved for the mark 1 ZBF, but the interests of speed and practicality won out
Compliments of the season to all who read this, Happy Christmas and a peaceful New Year
Andrew
Progress report on the upside-down shark. ( It swims in the air with it’s dorsal fin sticking down into the water)
The material is Formica sheet, sewn with braided fishing line and the epoxy poured in to seal the edges. The ballast will be lead shot poured in to the bottom until ‘she’ rides on her lines ( such as they might be ). The rudder will comply with the slot in the box.
What a pity all my water is solidly frozen until spring!
Rod,
if it swims upside down would this not make it an invertebrate?
Love your creation - do we know that Formica is latin for an ant? so the insect kingdom is involved in this creation too.
I have vrtually given up on training my flatulent cuttlefish - they persist in travelling backwards despite never having SEEN my Razor, and their tentacles won’t always fit into the box.
So this thread is watching the creation of a formica shark, a trimaran scow and a submarine footy (and a Savonious catamaran (dv)).
Practically radical and/or radically practical,the denizens of this forum
Thinks - how did Mary Poppins extract that hat-stand from her carpet-bag? Can we use this principle for the footy box and extract a Marblehead with “A” rig?
andrew
T’was very tongue in cheek Mudd. I was thinking of an unpowered thing which freewheeled a la autogyro. The forward motion coming from the forward motion just like all other successful perpetual motion machines You can’t blame me for trying to join in :lol:
You can sail a boat quite happily with a Savonius rotor that’s being rotated by the wind. The only problem -for radio sailors- is you need to reverse the roter, in order to sail on the other tack. On this free sailor, I just take the sail off the mast turn it upside down and drop it onto the mast again. my problem was this boat is too short and the turbulence off the rotor plays hell with the wind vane.
It’s worth it just for the look on people’s faces whilst they try to work out what’s moveing the boat.
My rotor is purely a sail. linking it to a propeller is too much like hard work, but others have done it.
Rotors are surprisingly efficient and half this sail area would be enough.
The ‘topsail’ is at 90 deg to the ‘mainsail’ and is there to keep the sail spinning in the light and fluky winds of my local pond.
The rotor is far too big as it’s made from 2ltr plastic bottles on a 46cm boat - all I had to hand at the time. My first boat was longer with a ~1 ltr bottle rig which from a 20year old memory was a better sailor.
Marchaj’s ‘Aero-hydrodynamics of sailing’ covers the hard science of rotors, most work is about Fletner’s rotorship which had powered rotors.
More recently the Coustesu foundation commissioned the 31m ‘Alcyone’ which used air pumped out of vents to give the same effect, but without the problems of spinning a cylinder.
I don’t know of any other free spinning sails, needing to change the direction of spin when you tack makes this more of a novelty than a working sail. My inspiration was the bird- kites with spinning wings, which of course only work on one tack- upwards.
Yes that is the type of rotor I was thinking of Ian. The control liner I was remembering was basically a powered version of the kite idea. The power coming from a diesel engine and prop. on the nose.
A diesel-powered footy is quite an idea - might be marginally legal but the smell and effect of the ether would compensate
iandunmore - thank you for the picture and recollections
I was thinking of getting the VAWT to roll out a strip of blotting paper in the forwards direction so that the boat sucked itself along.
There may have been some development required, and tacking would have been a nightmare! - not lease because of the inversion of the rotor
Although ironically “rotor” is a palindrome!
andrew
Wow, that Cousteau/Alcyone thing has so much potential. It uses expelled gas for propulsion! Link that to the flatulent squid, with perhaps a slight modification of diet, it might be possible to… Where’s my drawing board and my wifes ‘1001 ways to serve beans’ cookbook…the possibility of an 'Organic Footy’s creeps closer.
You can’t blame me for trying to join in :lol: