G
Guest
Guest
I'm looking for DIY- drawings about windvane- steerings. Anyone can help me? Sorry, for my bad english- knowledge.
Gerd
Gerd
Anchorite
Member
How's your French?? Loisirs Nautiques have a hors séries on DIY both
wind and autopilot; Very highly detailed (but in French)
wind and autopilot; Very highly detailed (but in French)
Joe_Cole
New member
Joe_Cole
New member
peterk
New member
hi gerd,
There is a book on selfsteering by Gerard (okay!) Djikstra
that has a lot of diagrams to guide you,
also names of specific designs.
I built my own vane with its own rudder
and a trimtab(flettner ruder) on it.
It steered well
more than 99% of my trip around the pumpkin.
The idea came from James Ogg - try google.com.
What size boat do you have?
good luck!
...peter , www.juprowa.com/kittel
There is a book on selfsteering by Gerard (okay!) Djikstra
that has a lot of diagrams to guide you,
also names of specific designs.
I built my own vane with its own rudder
and a trimtab(flettner ruder) on it.
It steered well
more than 99% of my trip around the pumpkin.
The idea came from James Ogg - try google.com.
What size boat do you have?
good luck!
...peter , www.juprowa.com/kittel
peterk
New member
hi gerd,
The book's author is Gerard Dijkstra: Selfsteering for Sailboats.
is your main rudder inboard or on the transom(heck)?
A transom rudder with a trimtab is simple and nifty...
...peter
The book's author is Gerard Dijkstra: Selfsteering for Sailboats.
is your main rudder inboard or on the transom(heck)?
A transom rudder with a trimtab is simple and nifty...
...peter
Joe_Cole
New member
There is also a book "Self Steering for Sailing Craft":John S. Letcher, Jr. 1974. Which is helpful.
I've been toying with making a vane, mainly because it would be a fascinating project over the winter. Trouble is that I can't work out the linkage. Ideally the vane would fit on top of the rudder (transom hung) and operate a trim tab. The problem is that it looks as if the trim tab would move the rudder(which is fine), but then the rudder would move the vane's angle to the apparant wind making the rudder move even more. ie, it would create dramatic oversteering. Can't work it out. I think I'm rambling now!
Ah well!
P.S. Do you have a copy of Gerard Dijkstra: Selfsteering for Sailboats that I could beg, boorow or steal?
Joe
I've been toying with making a vane, mainly because it would be a fascinating project over the winter. Trouble is that I can't work out the linkage. Ideally the vane would fit on top of the rudder (transom hung) and operate a trim tab. The problem is that it looks as if the trim tab would move the rudder(which is fine), but then the rudder would move the vane's angle to the apparant wind making the rudder move even more. ie, it would create dramatic oversteering. Can't work it out. I think I'm rambling now!
Ah well!
P.S. Do you have a copy of Gerard Dijkstra: Selfsteering for Sailboats that I could beg, boorow or steal?
Joe
halcyon
Well-known member
Wouldn't you lock out the tiller if you were useing a trim tab.
This would then allow the trim tab to steer the minor caurse changes to hold the heading
Brian
This would then allow the trim tab to steer the minor caurse changes to hold the heading
Brian
G
Guest
Guest
Hallo,
thank you very much for the advice. In reply to your questions:
- My boat is 33 ft (Maloe)
- The rudder is inboard
- My French is more bad then my English, nevertheless I'll call to Loisirs Nautiques.
Gerd
thank you very much for the advice. In reply to your questions:
- My boat is 33 ft (Maloe)
- The rudder is inboard
- My French is more bad then my English, nevertheless I'll call to Loisirs Nautiques.
Gerd
Joe_Cole
New member
That's an interesting idea.
I think that, strictly speaking, a trim tab is used to "drive" the main rudder. I.e. the trim tab moves one way and forces the rudder the other way. The main advantage being that a trim tab needs less effort to move it and can therefore be driven by a vane.
Doing it your way the tab would effectively be a "mini rudder"
Mmmmmmm. You've got me thinking now! Thanks!
Regards
Joe
I think that, strictly speaking, a trim tab is used to "drive" the main rudder. I.e. the trim tab moves one way and forces the rudder the other way. The main advantage being that a trim tab needs less effort to move it and can therefore be driven by a vane.
Doing it your way the tab would effectively be a "mini rudder"
Mmmmmmm. You've got me thinking now! Thanks!
Regards
Joe
halcyon
Well-known member
Think there's a yacht in our yard with this type, I'll have when I'm down.
Thanks to this tread at least I think I can understand the working of the Hassler we have fitted now.
Brian
Thanks to this tread at least I think I can understand the working of the Hassler we have fitted now.
Brian
spark
Member
Somebody (I think it might have been Moitissier) argued that the vane mounted on the rudder works fine so long as the axis of the rudder hinge intersects the axis of the trim tab hinge below the level of the vane. I worked all this out last year and I seem to remember it made sense (in theory) but haven't yet got around to building/testing it so I may have missed out something pertinent.
I'm told that any trim tab only works well on a boat that is naturally good at holding its course because the initial action of the tab tends to accentuate the error, steering the boat away from the desired course. This effect is momentary, lasting until the tab turns the rudder in the correct direction, but if you have a skittery fin keeler it can be a problem, apparently.
If Gerd has an inboard rudder then he'll have to go for gear that acts on his tiller, which probably means a servo type to provide adequate power. More complicated as a diy project but by no means impossible.
I'm told that any trim tab only works well on a boat that is naturally good at holding its course because the initial action of the tab tends to accentuate the error, steering the boat away from the desired course. This effect is momentary, lasting until the tab turns the rudder in the correct direction, but if you have a skittery fin keeler it can be a problem, apparently.
If Gerd has an inboard rudder then he'll have to go for gear that acts on his tiller, which probably means a servo type to provide adequate power. More complicated as a diy project but by no means impossible.
Anchorite
Member
Bonjour Gerd: the Loisirs Nautiques book is called 'Connaissance du Pilote
Automatique'. It is packed with drawings of both vane and electronic diy
projects (and also explains why Moitessier's system isn't worth doing).
The book is Hors séries no 9.
Automatique'. It is packed with drawings of both vane and electronic diy
projects (and also explains why Moitessier's system isn't worth doing).
The book is Hors séries no 9.
Joe_Cole
New member
Thanks. I’m having difficulty getting my head round this one!
Do you mean that the axes of the rudder and trim tab are not parallel and that (assuming the rudder axis is vertical) the trim tab axis points backwards and downwards? The two axes would therefore meet at a point, say, 4ft above the rudder and the vane would be above that point.
If that’s what you mean (if you understand it) then
a. I don’t see why it works…I’ll have to think it through!
b. It’s exactly what I need to fit on my boat (for reasons other than the steering…….boarding ladder, lifting rudder in the shallows, avoiding the backstay etc)
Thanks.
Incidentally FWIW there was a good write up on different wind vane systems in PBO August 98.
Regards
Joe
Do you mean that the axes of the rudder and trim tab are not parallel and that (assuming the rudder axis is vertical) the trim tab axis points backwards and downwards? The two axes would therefore meet at a point, say, 4ft above the rudder and the vane would be above that point.
If that’s what you mean (if you understand it) then
a. I don’t see why it works…I’ll have to think it through!
b. It’s exactly what I need to fit on my boat (for reasons other than the steering…….boarding ladder, lifting rudder in the shallows, avoiding the backstay etc)
Thanks.
Incidentally FWIW there was a good write up on different wind vane systems in PBO August 98.
Regards
Joe
rwh
New member
I think building your own windvane successfully also has a lot do with whether your are a Mechaniker or Ingeneur? My job is sitting behind a desk and having 2 left hands, I would never attempt to build a windvane by myself. Was ist Dein Beruf? Cheers, Ronald SV Bremer Speck (http://www.bremerspeck.com)
martinb
New member
I have Bill Belcher's book 'Yacht Wind-Vane Steering- How to plan & make your own' ISBN 0-7153-8176-8 (published in 1982). The book includes plans for several systems and has a foreword by 'Blondie' Hasler claiming it is just about the best book on the subject he has seen- praise indeed.
Martin
Martin
spark
Member
"Do you mean that the axes of the rudder and trim tab are not parallel .."
Yes. The boat that I'm currently building has a raking sternpost so the rudder will have a plumb trailing edge on which the trim tab will be mounted. The axes will intersect at the top of the rudder. Not sure how your example of plumb transom with a forward rake would work.
"a. I don’t see why it works…"
Dredging my memory and looking at my sketches I think the theory goes something like this:
Imagine the boat on a close reach on port tack.
Vane is mounted on rudder and set up feathered to the wind.
Boat heads up to wind because of waves/heel/whatever.
Forward face of vane is presented to wind and rotates the trim tab in a clockwise direction (viewed from above).
Trim tab (after momentarily accentuating the undesired turn to port) pushes the rudder blade (and the boat) to starboard, as desired.
Imagine that the rudder is hung on a plumb sternpost and the trim tab is hung on the plumb trailing edge of the rudder - parallel hinges, say 18" apart.
When the rudder turns to starboard the vane turns with it and two things happen:
a. there is a slight rotation of the vane to starboard.
b. the vane is moved through the air at the end of the 18" lever.
Both of these tend to rotate the vane clockwise, thereby increasing the turn to starboard.
The result of this is a wiggly course (or even a gybe if the trim tab is too powerful?)
Now imagine a raked sternpost and plumb trim tab - the axes of the rudder and trim tab hinges intersect somewhere above the rudder and the bottom of the vane is mounted as close to this intersection point as possible.
As the rudder turns to starboard the intersection point is static.
The vane rotates around this point describing an arc in a plane that is perpendicular to the rudder axis (hard to describe - easier to demonstrate).
This means that the the rotation of the vane to starboard is reduced (the steeper the rake of the sternpost the better), mitigating undesirable effect a.
Undesirable effect b. is obviously reduced by moving the axis of the vane closer to the axis of the rudder - if they intersect then it will be all-but eliminated.
Clear as mud.
Yes. The boat that I'm currently building has a raking sternpost so the rudder will have a plumb trailing edge on which the trim tab will be mounted. The axes will intersect at the top of the rudder. Not sure how your example of plumb transom with a forward rake would work.
"a. I don’t see why it works…"
Dredging my memory and looking at my sketches I think the theory goes something like this:
Imagine the boat on a close reach on port tack.
Vane is mounted on rudder and set up feathered to the wind.
Boat heads up to wind because of waves/heel/whatever.
Forward face of vane is presented to wind and rotates the trim tab in a clockwise direction (viewed from above).
Trim tab (after momentarily accentuating the undesired turn to port) pushes the rudder blade (and the boat) to starboard, as desired.
Imagine that the rudder is hung on a plumb sternpost and the trim tab is hung on the plumb trailing edge of the rudder - parallel hinges, say 18" apart.
When the rudder turns to starboard the vane turns with it and two things happen:
a. there is a slight rotation of the vane to starboard.
b. the vane is moved through the air at the end of the 18" lever.
Both of these tend to rotate the vane clockwise, thereby increasing the turn to starboard.
The result of this is a wiggly course (or even a gybe if the trim tab is too powerful?)
Now imagine a raked sternpost and plumb trim tab - the axes of the rudder and trim tab hinges intersect somewhere above the rudder and the bottom of the vane is mounted as close to this intersection point as possible.
As the rudder turns to starboard the intersection point is static.
The vane rotates around this point describing an arc in a plane that is perpendicular to the rudder axis (hard to describe - easier to demonstrate).
This means that the the rotation of the vane to starboard is reduced (the steeper the rake of the sternpost the better), mitigating undesirable effect a.
Undesirable effect b. is obviously reduced by moving the axis of the vane closer to the axis of the rudder - if they intersect then it will be all-but eliminated.
Clear as mud.
Joe_Cole
New member
Yes, clear! Thanks.
Well done, it's difficult without miming or pictures isn't it?
I don't think it will work on my configuration unless I can mount the vane on the rudder axis and use an extra linkage to the tab.
It sounds as if you are planning to use a vertical axis vane. Have you thought about a horizontal axis? More power.
Well done, it's difficult without miming or pictures isn't it?
I don't think it will work on my configuration unless I can mount the vane on the rudder axis and use an extra linkage to the tab.
It sounds as if you are planning to use a vertical axis vane. Have you thought about a horizontal axis? More power.
halcyon
Well-known member
Joe
Look at page 58, Nov PBO, stern of the Discus.
May help, may not.
Brian
Look at page 58, Nov PBO, stern of the Discus.
May help, may not.
Brian
spark
Member
Glad it made sense - made my brain ache a bit to put it into words.
I'm going to try a vertical vane to start off with. I like simplicity - fewer moving parts = less to go wrong. If it doesn't work I can modify the gear to take a horizontal vane.
I'm going to try a vertical vane to start off with. I like simplicity - fewer moving parts = less to go wrong. If it doesn't work I can modify the gear to take a horizontal vane.