Vane and other automated steering systems
|Dave Cooper 6||23/12/2019 16:35:34|
|171 forum posts|
I know practically nothing about this subject but am willing to learn.
Now that my RAF launch is nearing completion, I would like to tackle a nice cruising yacht next. As an amateur engineer, the Idea of vane steering is quite fascinating...
If possible, I would install radio as well, plus an auxiliary motor as a back up, My first attempts are unlikely to be successful and I don't want to be stranded mid-lake !
Thanks for any help /suggested reading etc.
Merry Christmas to all,
|Malcolm Frary||23/12/2019 19:29:31|
|895 forum posts|
Auto stering systems like vanes, Braine gear and weighted rudders were intended to prevent steering - their job was to maintain a heading to the wind. So subtle corrections rather than full steering, implying rather different rudder requirements. Radio boats tend to have rather more rudder than self steerers. In either case, the really important consideration is balancing the rig so the boat will at least try to sail straight.
One thing about yachts is that they tend to not get stranded in the middle of a lake. If the air moves, so do they provided they don't have anything to add drag. Of course, having an island in the middle of the lake adds its own uncertanty. Being stranded is different to being stuck.
Edited By Malcolm Frary on 23/12/2019 19:31:52
|Dave Cooper 6||23/12/2019 19:59:00|
|171 forum posts|
Thanks for getting the ball rolling Malcolm - you've raised some good points there...
I wonder if anyone has a photo or two showing the actual mechanism(s). Ray and Roy on another thread have given some good descriptions, but, there's nothing like a picture /drawing to aid understanding.
One thing I've noticed about model yachts is the lack of any 'slot' effect - a known powerful aerodynamic driver between a genoa and a mainsail on full-size. Is this because a single sail winch cannot sheet in /out in a co-ordinated way to allow this. Also, how does one manage to 'goose-wing' when going downwind ? Would a vane help to maintain course for this ?
I hope to live and learn,
|Ray Wood 2||23/12/2019 20:40:14|
2048 forum posts
The model yacht works exactly like a full-size yacht with the slot effect, and yes the jib and main are adjusted proportionally to achieve the same lift from the sail shape to propel the boat forward. It is also easy to sail goosewinged directly down wind with a balanced rig. Take a look at the Dragon Force RG65 if your looking for entry level yacht, these are very popular these days for racing 😀
Edited By Ray Wood 2 on 23/12/2019 20:45:28
|Tony Hadley||23/12/2019 21:01:25|
897 forum posts
I can remember starting a thread on vane sailing some time ago in the Sailing Models section of the site. Attached below is a link. Under the thread 'Vic Smeed's Model Boat Designs' #23 there is a plan for the 25" MM class models Waterbaby and Sea Urchin. The plans show details of making a vane for smaller yachts.
In the Vane Sailing thread the moving carriage vane gear is mentioned, these are a superb piece of engineering, but only suitable for larger yachts e.g. "A" class due to their weight.
|Tim Rowe||23/12/2019 23:27:17|
405 forum posts
I have been following the conversation on the other thread. As has been said already, the development and availability of radio control heralded a major change in model yacht sailing and racing. The sport side is now divided with RC having the much larger participation but Vane racing is still enjoyed by many and some will say this is the sport of the purist.
A vane can be very simple. As a teen I designed and built a 32" model yacht and there was never any thought of being able to afford radio gear. Me and my sailing mate at the time used a plastic gear on the top of the rudder stock and another gear fixed to the shaft of a vane. The vane shaft ran in its own tube just the right distance away for them to mesh. The gear was adjusted by lift the vane to disengage the gear and re-set in the position for the desired point of sailing. It was remarkable efficient but obviously had to be manual changed at each tack. The sophisticated vanes are linked in a way that one setting works for both tacks. This is not the same as "self tacking" as the yachts still needed pushing through the wind at the pondside in order to tack.
Yes, I can see a bit of a project coming on and some transfer of technology from big boats and model aircraft to sail around a set of way points.
So Dave I am genuinely intrigued.
Stranded mid lake would be a real problem for me as I sail off beaches and open harbours. I always start from the lee shore so the boat would eventually drift back to me. If there is no lee shore I don't sail and should probably go flying.
|Dave Cooper 6||24/12/2019 00:06:36|
|171 forum posts|
Hi Ray, Tony and Tim - thanks for the great responses....
I can see that I've got much reading /studying to do already. I think it may be possible to combine vane and RC via some sort of clutch mechanism to disengage one and engage the other - as Tim alludes to, a sort of 'autopilot' system. This would make a cruising yacht nice an relaxing to sail (I'm too old for racing !).
Ray has dispelled my misconceptions over the rig side of things and Tony's links are just right for seeing real mechanisms and designs 'in-the-flesh'.
I must admit, I hadn't considered the sea, or harbours, as potential sailing sites (obvious really !). I'm struggling to find somewhere in North Wilts which is in easy reach.
|Malcolm Frary||24/12/2019 10:07:35|
|895 forum posts||
Any sailplan having more than one sail uses the slot effect, even ones that do not overlap, like the Genoa. Genoas are rare in models because of the extra complication needed to make them work, and extra weight of the gear needed to achieve this, but do exist. Spinnakers also exist, but are rare for the same reasons. Properly set up, the single winch can do nothing but operate the sails in a co-ordinated way (they are both ties to the same piece of string). Some yachts have an extra "twitcher" servo to give some extra adjustment on the jib.
Sail plans that do not have a loose footed (i.e. they have a boom) generally have the lower pivot set back about 1/4-1/3 of the way back, and often carry a leech line. This all ensures that the sail keeps its intended shape, and a side effect is that once you have the wind blowing over the transom, goose winging will happen, probably whether you want it or not.
A kit is a good place to start, even if only to figure out where you would have done better. DF65 has been mentioned, Victoria is very good, and there is a host of 1M long sailboats at very low prices, all of which are a good introduction for somebody who is not scared of improving things.
A simple plan build is also good, a favourite of mine was a free plan in one of the magazines frm the early '90's called "Akela". It reappeared for some time as the "XL 25" on a Dutch site, but that site now seems to have expired. If I did download the plan, I have since managed to misfile it.
|Dave Cooper 6||24/12/2019 11:14:42|
|171 forum posts|
Thanks for that correction Malcolm, and the extra information you have given on kits and plans. I'll get to these in due course.
The learning continues...
|Gareth Jones||24/12/2019 11:22:35|
791 forum posts
I am a member of the Vintage Model Yacht Group and have some experience of vane sailing with yachts ranging from 36R sized up to A class. There were a series of articles on vane sailing published in the Turning Pole, the journal of the VMYG a few years ago. I have scans of them and if you send me your email address by private message I will forward them to you,
There are free plans available on the web of an Ezi-build vane gear designed by Graham Reeves. I have attached a photo of the one I built to his drawings.
There is a link to the plans on the Llandudno model yacht club site here Vane gear
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