Model Boat Mayhem
The Shipyard ( Dry Dock ): Builds & Questions => Yachts and Sail => Topic started by: warspite on February 01, 2014, 02:07:12 pm
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I built a boat which requires a fin and bulb to remain upright, it is a sail vessel and I have a tempory 'pendulum' style solution fitted. The question is, to keep the vessel at the waterline and upright requires that the 'Pendulum' is a certain length, and the weight at the base is a specific amount, its fixing position is slightly further rearward (about 20mm) than the centre of the weight, I need and want to reduce the depth of the pendulum with a proper fin and bulb, but i do not want to create a weed catcher, the weights are not a lot (as I fitted too much weight internally and cannot remove it now to add it to the bulb and therefore reduce the fin length).
Is there a specific calculation/shape/design that will help, cantilever expresions etc, and materials - currently a brass tube with a brass base plate and tempory bolted galvanised washers. A fin and smaller depth will help enormously, the fin to give stability in helping to push forwards when being blown from the side.
I am concidering breaking into the vessel to remove the weight, but that has its own issues, total weight of the pendulum is 190g including 2x53g washers at the bottom, the vessel is really small and difficult to gain access to, I am concidering on building another to compliment it but if I can get this one to sit right and can then do this for the other as well. Sorry this is sketchy but I do not have photos of the vessel.
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It really is very difficult to answer this without a photo. If the problem is that the weight needs to extend further forward that the ideal fin shape, thus creating a weedcatcher, you may have either to get the mass of the weight further aft, and balance the hull fore and aft with a lump of leas in the bows, or make the fin into a plate keel so that it tapers down to the forward edge of the weight. Long keels are no bad thing - they help the vessel keep her course, though you do of course lose some manoeuverability and can't turn her on a sixpence.
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Speed is not an issue - but stability and the ability not to collect weed O0 , the vessel is a square rigger, but the issue is a long 300-450mm (its in the loft for the winter) pendulum which is made from about 8mm dia brass tube, the weight of which is part of the total weight needed (refered to my notes but the dimensions are a guess without physically getting up there and is to darn cold). so if the total weight is 190g and its length is say 400mm, the top of which has a M8 brass bolt soldered to a small angle plate for an offset, the bolt is in the hull and the tube has to match the centre of the keel, and the base of the tube is a small piece of brass plate drilled and slid onto to the bottom and then soldered facing forward by up to 40mm - acting like a tray for the balance weight which is either a single or double 53g galvanised washer, I think it was 2 so that makes up 106g at 400mm from the keel, not an issue for a large sailing vessel with a 1m mast, but this is a small 300mm+ vessel, not wishing to give weed a chance to wrap around a fin and bulb.
An original thought was to have a brass plate cut diagonally across the corners creating a triangular plate x 2, then using a dremel, cut a slot down the centre of the tube, wide enough to accept the edge of the brass traingular plate (almost like a rudder), then top it with a brass bolt (this screws into the hull through a special hole), then bolt the weights on to each side of the traingular plate like a sandwich and profile the bottom point to be flush with the washers, then cover in thin plastic card or just paint.
problem with this is the weight calculations, the overall length would be shorter than the 400mm, some of the weight would transfer up to the hull thereby reducing the pendulum effect, meaning that more weight would be needed to give the righting motion of the weight and hense the hull would end up lower in the water, detracting from an asthetic point of view.
Alternatively for strength place the traingular plates side by side a solder together, then fix the bolt and the weights as above, still I would have the same problem with weight.
Ideally I would prefer to remove the galvanised washers fitted inside, as ballast, and transfer these to the fin as a bulb, but will have to see how that turns out - now wheres my web cam, as a way of seeing whats where. {-)
adendum:-
the attached is the pendulum fixing point, the white strips left and right are plastic card, that was pre installed before the halves put together, this allowed a substantial amount of glue to be applied and acts as a positioning strip as well, it extended well to the rear and forward above the expected waterline, it allows the screwing of an M8 bolt into the underside, though I did find a M6 version and should have used that - and will on the future ships, the issue is that at least 2 x 53g galvanised washers are in the bows area - left of the picture is the bows. there is a place in the hull that would now be in the right of the picture (when the servo came loose) where I can cut it out again and attempt to remove the washers - though fixing it again will be a spherical ache.
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the sketch to the left is the current pendulum, the sketch to the right is what is prefered though as the brass plate is already cut it does limit what can be done. Is there any calculation or material choice recomended for the creation of a light fin and heavy bulb?, I suppose if it is not a fast boat then the strength of the fin is not as important as it is not under a lot of strain. I could mod the plate to remove the tube entirely then.
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Hello,
The usual way of making a Keel which will not collect weeds is as per my drawing,
I have done better drawings!!!.
Any Ballast needed should be placed at the bottom of the keel for maximum stability.
John. :-))
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Yes Ive seen this type, again it is the materials and a way of keeping the most weight at the lower level to maintain a righting moment, a thin and light fin in any shape with all the majority of the weight at the bottom, in the sketch the 40mm square x 6mm thk blocks are the washers, if I can just remove those from inside it would be easier to add them to the bulb area without losing trim (I dont really want this vessel sailing on its side, as due to the construction method, I built here in one half and attached the other when closing up, so the closing up side is an unknown as to being fully sealed).
If the brass sheet is just thick enough, I could dispence with the tube portion, I could move the ballast so that it was angled and therfore at the tip and may still give some equal trim for and aft of the bolt.
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Hello,
Using brass sheet you will have a lot of the keel weight too high up.
Keep the brass tube and ballast,but use plastic sheet in a shape similar to my drawing to blend the keel into the hull.
At the moment you have designed a very good weed catcher!.
John.
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Bow of the boat is to the right and the bulb is trailing so the angled section is slicing through the weed. :}
In the next few weeks I am off work so will have a go at getting in and trying to remove the weight, though now i am thinking about it I want to do it now - its just toooooo coooolld, bruurrr.
Just as a thought, I have seen pictures where there are sails between the main mast and formast, was this a common practice and did they help in any way (though in the films they never show this).
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Hello,
Your boat is not heavy enough to "slice through" any weeds.
All you can hope for is to deflect them.
I suggest you buy a pair of waders.
John.
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Darn it - thought of creating a sharp knife edge with the brass leading edge, might get told off for going equiped,lol
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Sails between the masts - look up staysails, and "fishermen's staysails". I suspect they are more use at 1:1 scale where you have lots of blokes to run them up and down and trim them: not so easy to control them by r/c. But then if foresails work ahead of the foremast, staysails between the masts must work in the same way. So if you could control the foresails and the(square) mainsails, then linking the staysails to the foresail sheets might work. Hmmmm.
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I just thought they gave push when the wind is from behind and just off one side slightly like directing the wind onto the next set of sails.
On a model of such a small scale I suppose they have no effect other than to push the vessel over if trying to tack.
Was just hoping they would help push forward rather than this boat going sideways, hense the idea to create a fin to help direct the push forwards.
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Hello,
Any chance of a photo of your boat ???
John.
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I dont have any of the finished boat, only found that on my sons phone, he had deleted the rest.
that and its not completed fully.
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Just as a thought, I have seen pictures where there are sails between the main mast and formast, was this a common practice and did they help in any way (though in the films they never show this).
@Warspite:
I built a square rigger a while back that included a staysail. I usually sail with the staysail off as it does not do anything of value on an RC model without the capacity to trim it accurately. It just increases heeling from my experience.
Re the keel, I have not read all the talk on this, but the physics remain the same - it is pendulum keel and so it remains as a lever with a weight on the end of it - to reduce sailing depth while retaining the same righting moment you need the fin half as long with twice the weight on the end. The extra weigh drags the boat lower in the water of course leading to another set of issues. Use lead for the weight. If you can do a sheet fin as proposed would help a bit with weed issues, but the lower the weight, the better.
See the link below for the square rigger I built, you may glean something from it.... It was built for a competition using recycled materials. A great fun build....learnt a lot...
http://www.youtube.com/watch?feature=player_detailpage&v=sTj-aqYUX9g
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Quality, milk bottle floatation, maybe the school project would like to see that as a follow up for next year :-)) , they could have their own sea battles with a way of taking a flag of the other boat.
So basically if I want to reduce the pendulum by half then I need to increase the weight by 2, theoretically, if I can get the other weights out of the boat and place them externally on the bottom of the brass fin then that will in theory help significantly, a bit of trail and error then :-))
Thanks for that. When building this boat I thought that plastic masts would break easily and a fear of them breaking meant that I made them in brass, there section would have been too thin to cope with the sails, but I may try an experiment to make the next boat with suitable lighter materials above deck.
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.... When building this boat I thought that plastic masts would break easily and a fear of them breaking meant that I made them in brass, there section would have been too thin to cope with the sails, but I may try an experiment to make the next boat with suitable lighter materials above deck.
From what I learnt building the recycle boat, with a square rigger there is little load on the masts, I could have made my masts smaller diameter and the spars a bit lighter but that was what I had available at the time. The many shrouds and sheets distribute the load to many parts of the boat so there are really very few high stress areas. With a square rigger there is sometimes load on the forward-running stays as well when sailing backwards (my square rigger sails backwards quite well). The mast load is really mainly vertical compression in any case. The only area on the boat under much tension is the bobstay, easily overloaded if one overdoes the tension on the many shrouds, they only need to be just firm, not tight I found.
As with any sailing model, adding weight / leverage below the water or reducing weight / height above the water leads to better outcomes. I had a free hand in the one that I built; if you are working to scale for a replica or such then you have some limitations to keep it looking right...
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With this KIT, the masts are very thin moulded plastic ok2 , thinnest about 2mm and some can be up to near 80mm long at about the top sail area, the mouldings are quite susceptable to warping, so structurally they were not that good, hense the brass, as the formast and main mast rotate via a solid link (borrowed from the aircraft side of modelling) and a servo, I was unsure if stock ABS tube would have been better, though not neccessarily lighter or would I be wrong on that score, would have certainly been less work with soldering etc, though the making of them was an experience never done before and sadistically enjoyable.
Some parts are better in brass as they allow a lot of give in handling and shore based obsticles - like concrete paving or walls cannot remove them easily.
I loved the rope linkages and the use of buttons etc, I tried to keep this boat quite simple, though a test sail did not give any confidence as it is underpowered for getting back to shore in a calm condition - tethered does not help. :embarrassed:
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With this KIT, the masts are very thin moulded plastic ok2 , thinnest about 2mm and some can be up to near 80mm long at about the top sail area, the mouldings are quite susceptable to warping, so structurally they were not that good, hense the brass, as the formast and main mast rotate via a solid link (borrowed from the aircraft side of modelling) and a servo, I was unsure if stock ABS tube would have been better, though not neccessarily lighter or would I be wrong on that score, would have certainly been less work with soldering etc, though the making of them was an experience never done before and sadistically enjoyable.
Some parts are better in brass as they allow a lot of give in handling and shore based obsticles - like concrete paving or walls cannot remove them easily.
I loved the rope linkages and the use of buttons etc, I tried to keep this boat quite simple, though a test sail did not give any confidence as it is underpowered for getting back to shore in a calm condition - tethered does not help. :embarrassed:
@Warspite:
You have not mentioned the size of this boat - I am assuming about a metre long?
It sounds like the use of the brass for the masts was a good idea, even more so if you have rotating masts instead of sheeting the yards as I did. The rotating mast method has much less tangle of lines but the masts will be carrying more load. As you indicate, handling the boat can be a problem, they are easily damaged long before they reach the water...
Re the test sail - a square rigger is underpowered compared to modern sail plans, but generally has a lower centre of effort. The square rigger is totally different to sail to other sailboats (such as a Bermuda rig) - they will only point about 70 degrees to the wind at best (compare to Bermuda at around 20-30 degrees), so upwind sailing is a challenge. Downwind or reaching is easy of course. Tacking is generally done using a box turn (something like doing a three point turn with a car). The forward mast needs to be able to turn the sails separately to the after masts to allow steering and tacking.
This video shows most of the sailing manoeuvres for a square rigger as well as more on the build. See 8:50 through to 9:20 for a quick look at most of the moves:
http://www.youtube.com/watch?feature=player_detailpage&v=zZGjFR5CYUE
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Yeeeaaaa, about that, the boat is an off the shelf conversion ;) , it has rotating for and main masts, both rotate at the same time in the same direction, the rear mizzen is fixed but for the triangular stay type of sail over the stern, which is free running, well slightly tethered, thought was that if the rudder turns the vessel right, the triangle sail will push over to the left assisting the turn (in practice it has no effect at all - maybe size is the problem :D ). The vessel is about 450mm overall in length - including the bowsprit - he said sheepishly, surprisingly the vessel could take a lot of weight when it was just the hull put together and sat in a body of water, it took about 500g+, though this never works out as you expect, as the majority of the weight ends up above water - darn it.
With the counterbalance as drawn, it sits quite straight and level, even heeling it over, it returns quite easily to vertical, its getting the same effect with a smaller fin and bulb that I am more interested in, I'll have a look at the vid in a mo. O0
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Fantastic, reverse gear as well, I know they are difficult to control and though this was an experiment, I quite like it and want to build its sister and then go on to some competition, its getting the balance right, I could have just made it run on props but that would be cheating. I dont have access to a body of water with nice clean accessible edges and no weed, and wildlife, or a rescue vessel, most of my boats are plastic fantastic WWII vessels, 1 is too small, one is a 1/72 MTB vosper and nose dives, another is long and slim and takes an age to get any where and the corvette hasnt seen water for near on 6 years if not longer. :embarrassed:
work you have to do it.
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@Warsprite:
Yes, at 450mm long including the bowsprit it will be extremely difficult to sail I would think. If you are considering building another, I suggest you plan something around 900-1000mm long (overall) - any bigger and transport becomes an issue without de-rigging.
I found the aft sail (it is a spanker on my recycle boat) was not much help. I also found the flying jibs had a marked effect on direction control being so far forward of the centre of the boat, only small sail area but a lot of effect. With mine, the forward mast is more useful in controlling direction than the rudder at times, even with increased rudder size. The main and mizzen mast sails all swing together and work as a team. The differential between them and the foremast provides most of the control and manoeuvrability.
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So Ive been reading it wrong when I read threads on how to operate the masts >:-o , on several they operate the for and main, which is what I have done, I pressume the rear two operating sets up different aspects to a tail or side ways wind, my rear mizzen is fixed and is why it may not operate as well, it might be something I can change on others if the space is available and a little bit of 'adjustment' on this one using a little inginuity.
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Hello,
We seem to have got away from sorting out the Keel position, onto other things!.
All yachts with sails need a Keel, but, where to put the keel to enable the boat to sail correctly?.
Too far forward on the hull and the boat turns into the wind, to far aft and the opposite happens.
Things here are getting rather complicated, so I suggest a visit to the following website.
http://www.onemetre.net/ (http://www.onemetre.net/)
This site is one of the best I know about, not an easy site, but very good.
Follow the advice given and you will only make ONE Keel !!!.
I have two very large boats built with the same info.
Both boats are a pleasure to watch and to sail.
John. :-))
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Thanks for the link, in retrospect, I need to make the fin as light as possible, maybe thick plastic card attached to a brass bracket attached to the screw, and then put the washers or lead weight at the very bottom edge, if I can get the washers out of the hull, will see what weekend brings, I am pressuming the fin will give some control on side ways drift, being that it is similar to a rudder.
As for the sails, that question was just to enquire if the installation of a stay sail ? could give more control like the rudder, but obviously not.
Until it is run in anger I wont know the answers, just would prefer to have a shallower keel fin before hand as the current set up will act like a trawler.
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Update, boat brought out from loft :D , weighed the various pieces of brass and found some interesting materials that could be used, like two sheets of aluminium one about half a mm thk 4" x 10" (54g), the other about 1mm thk and the same size (but with some slots @ 94g).
The current counterbalance weighs about 150g - not the 190g as first thought, its also the 10" long which is about 250mm +, I thought I had the weights of the various brass tubing, I do, its just in the loft.
I have a prototype counterbalance that was constructed from the airfix shutter booter rockets, filled with M8 washers and secured with epoxy, though this pushes the vessel over to one side as it is not stepped to be under the keel, and it rotates easily as it is hard to lock it against the hull bottom, it also is a lot heavier and makes the boat sit below the waterline, so I am not keen to use it.
other dimensions are - hull above waterline to bottom of main mast 50mm approx, main mast 12" from deck approx, I think the hull below the waterline is 44mm, overall its about 20" long 500mm give or take including bowsprite.
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Update 2, cut into the hull and in the process of trying to use a web cam to vid the inside, wrecked the web cam - it was too large to fit in either the rear or the hole that was cut, so stripped it down, very thin wires which dont take much to break :embarrassed: .
found the two washers inside and with a bit of persuasion got them out, now I have sealed the hole and need to check that the seal is good before trying a new fin and bulb.
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Update 3, well tried the hull - now sealed O0 , happy chappy, tested the weight - wow after removing 100g from 20-30mm below the waterline and fitting a tube at 227g including M8 screw in it, sat at about 140mm below the waterline and then attach a 210g weight in the other end of the tube, she sits too low ie 437g at 140mm, with either end pulling the rear down, so tried 150g just under the heavy end of the tube, forward of the screw and pushed over to the left of centre, it still sits lower in the water than I want, but if i make the replacement as 350g ie 210g fishing weight and a 140g in other fishing weight just forward of the screw and with a thinner lighter fin/sail board, then it might just work, maybe a little deeper as well.
To get an equally grouped weight what do you use for melting lead and what is the safest and prefered method for moulding it to a specific diameter. I have a 210g weight, it appears to be moulded with a mesh internal connecting to an eye for the line, for this I was concidering just cutting off the rear, then by melting some other weight which I can see if can get from say - quickfit so that it sits in a cup of a made diameter and voila, all the weight together. encase the lot in epoxy with the connection to the hull ie fin and brass tube connecting rod.
As long at the combined weight is 357g and she sits as expected and heel over is easily righted then jobs a good un.
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@Warspite:
Sounds like you are heading the right direction.
Rather than melting lead (a dangerous process at the best of times) you may perhaps be able to hammer the sinkers you are using to a suitable shape? I have done this for as couple of ballast weights I needed and it worked out pretty well....
If melting lead, make very sure there is no water about as it is will cause violent explosions as it flashes to steam. Lead melts at quite a low temperature and with a gentle flame can be pretty controllable - but be careful....
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OKAY DOKEY, not too keen on melting it - hammering I can do :D , just have to generate about 330g at about 165mm to acheive the same righting moment, although a little less may be better.
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%) , well here is my NEW sail board (fin and bulb), it weighs in the region of about 350g (after a bit of weight reduction to the rear part of the bulb :-)) ), tomorrow I will be trying it in the test tank on the boat and see how it fairs, before the reduction, she sat tail heavy but I am hoping that the loss of 22 or so grammes will have a more positive effect, will see.
I did go looking at what others had done, and the method employed was basically a thin brass tube inserted and bent through a brass plate soldered to a brass screw which was cut down to reduce its distance from the hull. Then after fitting the fishing weight into a copper straight fitting epoxy was poured in and left to set, whilst it was setting, pieces of cut lead - thanks to the local fishing tackle shop for that - were pieced in around the tapered weight, then more epoxy added.
The outer plastic tube was fitted and glued together, which left a 3-4mm gap along one seam, this meant that the other end of the brass tube suitably bent slid down the seam into the back of the copper fitting, this was then epoxied in, note the brass tube extended past the fixing screw by about 110mm facing the bow (this may cause issues later - like having to permanently fix the sailboard to prevent it spinning to the rear).
Then backfilled the whole lot with a roll of lead and filled with epoxy, once set, it was weighed - wow 350g +, that is without the fin. Well the fin was made from about 1mm sheet in two parts - plaswelded together at the 'bow' and slid over the brass tube - like a rudder, the thickness was so that I could profile the front and rear, which in hindsight I should have just made it from very thin material and let it naturally form about the tube infilled with epoxy - more of a knife then.
After sealing and checking watertightness, then started to cut away excess to get the weight down as it had gone to just shy of 400g, got it down by angling the rear part of the fin and then having to reseal, about 380's so cut the bulb at a 20° at the rear, down to 370's, tested attached to the boat and was slightly tail heavy, so after another cut off, so it was about 45°, this brought it down to about 350's, but it has not been tested yet - but it has been painted so hopefully it will remain water tight, maybe a couple of more coats of paint.
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Looking good! :-))
Will stay tuned for updates...
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That was the best side - dont tell stavros I painted the outside of this outside :embarrassed: , in this weather {-) - fool me, if I lose it they only have to check my fingerprints against :police: - well actually I dont think they have them. ooooo am safe then, b****r stav is on.
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Well did a wet test - in the bath - sorry no photo, to busy trying to get her to sit upright and not to one side, large crack heard while trying to adjust the fin - DOH. tried again and no bubbles seen, so tried a heel test, hard a port and then hard a starboard, she rights herself, but I then noticed she was sitting lower, yep full of water, so after removing it, I may need to find out how to reseal her tomorrow, I know the bowsprit allows the water out - quite quickly actually, that's a good thing. I maybe needing to make a proper stand and permanently fit the fin or reseal around the connection to the hull, and I don't know if the leak was due to a badly sealed gun deck or something else, so need to get the test tank down.
I am trying to upgrade this pc to win7 and so the pc is taking up the space needed for the test tank, hopefully everything is nearing completion.
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.... large crack heard while trying to adjust the fin - DOH
That sounds ominous :o {:-{ :((
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The extreme heel is to account for wind conditions, as you know, moving forward and staying upright don't always usually occur with yachts let alone square riggers, the test tank will see if she is leaking while vertical, if after an hour she is still dry, the heel to the right for an hour as I know this was the best sealed side, then to the left as this is the suspect side, though I now consider the bow may have an issue just under the bowsprit.
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Not going well >:-o, definite leak on vertical, the crack sound may have been the inside fixing for the fin.
so I need to consider what is the best course of action, tried some superglue around the entrance and it worked its way up the thread while it was on its side drying, so the thread needs to be cleaned out, but the way this is going this action might just break the complete connection and the whole stud will break free, so again a bit of thinking needed, its a slow leak but enough, it would have sufficient time to run for about an hour if vertical, but I need to find the other leaks to allow for the extreme heel, so need to fix this leak before moving on to the next.
An option I was thinking of was to definitely break the connection and try to reseal the stud etc back to the inside while it is loose, but that means that the cleaning out of the thread would be problematic.
I do need to fix the fin though, by fitting additional stiffening to the bolt, the fear is that the single brass plate connector between the bolt and the brass internal tube will break, so need to fix this as well to prevent a sinking.
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Well I think have sealed it, she's been in the test tank all afternoon, I find it difficult to tell if she is leaking, so took her out and she did not appear to have any water inside, but bubbles are appearing around the area of the connection, though I am unsure as to if this down to a leak or the bubbles from the bottom of the test tank, I am trying to use the steps that are on either side of the vessel to gauge if she is taking water on, but as she moves about it is sometimes difficult to remember where the water level was {:-{
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found the leak, its the sailboard again, even after doing a major sealing exercise, a couple of pin holes and where the screw passes through the stiffening plate, though it seems like fill one hole and another appears.
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Who said hot lead was dangerous? Not according to mythbusters %%
http://www.youtube.com/watch?v=UZio0f7fP04
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I'm to chicken to do THAT :embarrassed:,I suppose its not much different from the fire walkers, same principle, minute time in contact with the hot surface means the skin can take it.
I'm more concerned with the fumes from all the epoxy and glues I am using to fix and build the last 3 vessels - not to mention the flux fumes that escape. :D
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found the leak, its the sailboard again, even after doing a major sealing exercise, a couple of pin holes and where the screw passes through the stiffening plate, though it seems like fill one hole and another appears.
Some silicon sealant perhaps? I have use something called "wet area silicone" intended for bathrooms etc and it is great
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Plastic cement was the reason :embarrassed:, I thought - "i'll fill the top up with some plastic cement and when it goes off it will stop up all the inside holes" - yea right, all it did was weaken the plasticard and when gripping the top it split the card and a hole appeared - DOH !!!!!!
So I need to try again before committing it to water again.
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Can you not pour in some epoxy coating?(Z-poxy?) This should be inert so far as the plastic is concerned, and fluid enough to flow into the pinholes and cracks. Just put some masking tape on the outside of the hull to stop it dripping right through.
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.... Just put some masking tape on the outside of the hull to stop it dripping right through.
Now THAT is a clever trick :-))
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Will have a go, though for what it is worth the holes, not that big and I did think of putting a hole in the main body and filling all the top section with some epoxy, then repair the hole created. :-)
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Well, after a 12 hour soak in the test tank she sat quite happily as well, butter fingers here dropped the sailboard >>:-(, resulting in a major crack so had a think and tried to 'modify' the sailboard to remove the air pocket, ended up having to rebuild the whole thing, so waiting on the epoxy to cure, before a light clean up and doing the painting tomorrow.
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Replacement painted and sat in test tank again, will post a photo soon. :-))
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Here is the photo, quality isnt that good but it does show the change to the rear of the fin
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Hello,
It appears that the Fin is only connected to the hull at the rear end.
If, this is the case, the slightest collision with weeds, the lake bank, or the bottom of the lake, will cause a massive leak into the boat.
Every Fin I have ever seen has been connected and faired into the hull along its whole length.
If the Fin was hit while sailing the Fin could be turned relative to the boat Hull and act as a Rudder !.
I really think you need to alter things before sailing.
John {:-{
www.john-dowd.co.uk (http://www.john-dowd.co.uk)
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I Know :-) , the next step is to find a way of locking the fin to the keel at the front, currently there will be another nut that will lock against the nut at the hull, but for the front was thinking of just having a plate that is bolted to the top of the fin and is rotated up and fixing to the fin with another bolt, to act like a catch, this is all a prototype for now, may actually consider plastic welding another fixing point at the bow, but that will definetly mean having to reseal again.
Its sister ship (when I buy it will be simpler.
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Hello,
I am out of this !!!.
John. :o
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{-), I know it is strange way of doing it, I don't usually build sailing vessels and the fixing point was alright for the original set up, but as that was going to make sailing like a fishing trawl, thought I might change things, but found that all the weight ended up forward of the fixing point.
So after making a decision will stick with it and see where things go - I mean, even the idea of the prop didn't go to plan {-). she's only been on water twice, both times there was insufficient wind to push her very slow.
Current plans are to look into permanently fixing the sailboard - at 2.5 foot high, the transporter that I will have to build will be strange.
Also she's been sat in the test tank all week and hasn't shown any signs of letting water in, next test is the heel to the right.
In conclusion - the fixing point is wrong and with a little bit more thought would have been further forward and been direct on centre, the shapes better and less problematic for alterations (no air tank effect), it spinning around hasn't been tried yet, will see how the heel tests go, if it does spin then it is more than likely that it would sink anyway as all the weight will be over the rear and the ineffective prop shaft would allow water in as it passes below the water line - even with grease in. But its all a learning curve - (I want to do two others, a sister and a smaller vessel as completion but will see) - quite chicken to let it go out on water at the moment, always was cautious, lol.
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Due to ill health and all down to new meds >:-o , after the vessel has been sat in the test tank for nigh on two weeks now, other than natural evaporation of the water in the tank, she has not budge and decided to start the test, today started the hard heel to the right, the first hour or so, no change, though to be honest this heel is up to the gun ports. Just need to do a 10 minute with gun ports under water, this side of the vessel should be water tight.
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Well the first heel test to the right went okay, sustained heel to the right, short of the gun ports :-)) , 2nd test taken to the decks awashed, let some water in about 10 minutes, but not enough to worry about.
I tried the hard heel to the left, and I could not recreate to just short of the gun ports, so went straight to the water just above the bottom of the ports and it took a lot of water on, so the sealing of this side needs to be done. Was expecting this, as this side was always suspect so getting the glue out when I get to the workshop.
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Well its official, its an almost ran, oh it sails ok, by that it didn't sink, moved quite well, considering the wind was patchy, why almost ran - when it sailed fine -- IN REVERSE {-)
Yep it sails better in reverse than forward, I had little or no control as such, so without more experience its going in the loft to languish, and plans for others is scrapped.
Sorry, as I was on my own and had left my phone in the car, no video or photos. <:(
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@Warspite:
Hang in there!!! RC square riggers are REALLY difficult to sail at the best of times.
The first requirement is a gentle but consistent breeze. swirling or gusting winds make it really hard to work out what you are doing.
Add a pennant on top of the highest mast, this may help to show you where the wind is from on the water
I found an oversize rudder helped a bit, but because the sails are the main source of power and steering you need to get the hang of where to angle the square sails to get it sailing across the wind. You may also need to balance the jibs against the spanker, or else one end of the boat will overpower the other. If you have the facility to furl some of the (higher) sails this may also help with control.
If it sailed backwards, that is great, that just means you had the sails on the opposite angle. :-)) :-)) :-))
Also a square rigger will not sail upwind or close to the wind (unlike a Bermuda rig). While a Bermuda rig will sail within twenty or thirty degrees of the wind, with a square rigger, you will at best get it to sail about 70 degrees off the wind, so sailing upwind is a long hard job.
And finally, tacks are also difficult (turning the bow of the boat through the wind) until you get the hang of them; it took me hours of sailing to get one right and even then it remains unreliable. You have to do them a bit like a three point turn with a car in a narrow street - it involves sailing backwards part way through the turn.
For a start, you will find it MUCH easier to gybe (turn the stern of the boat through the wind)
Have another try sometime, they look great on the water....
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I think I read somewhere, that it was not uncommon for square riggers to wear, rather than tack, if the winds were not favourable.
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%) sorry, being a landlubber and motorised - most of the model boats I sail are powered, so sail is a new thing to me, it did sail (one comfort), it leaned over at one point with a gust - and I nearly had a moment - where trouser would need to be changed, lol.
I had to travel to find a water where there was access all around and early enough not to embarrass myself if the thing went to the bottom, though while retrieving it the crud around the edge gave me concern (and I still have to clean it off yet - where's the marigolds and a disinfectant - oooooooo DDT that'll do nicely - just kidding). most of the places around me are inaccessible but for small fishing platforms, plant life and notorious for weed under the surface - oh and lots and lots of Canadian geese and swans - so tons of crap all over the place. >>:-(
It was B****y cold as well, so time was restricted - I hate the cold.
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....it leaned over at one point with a gust - and I nearly had a moment .....
Don't be too concerned with a sailing vessel leaning, that is to be expected as the power comes on from the sails when the wind is anywhere but dead ahead or behind. Heeling of 50-60 degrees in a gust should not be unexpected, especially for a small boat such as this one. The weight is primarily in the keel, so it will stand up again once the gust dies off... As long as it is reasonably waterproof you should have no issues.
As mentioned in an earlier post, try for a gentle but consistent breeze, earlier in the day may help depending on your locations. As for the cold.... a good coat, thermals, gloves, flask of tea or coffee and a tot of rum.... or even two........aaarrrrghhh....
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ooooaaarrrrghh went more like oooeeerrrrr when it heeled {-) , of the sides to heel to, it did it the side I am not too sure about.
The other, the right, is known to be definetly sealed, the other was not, but after applying lots and lots of modellers cement I hope it is more watertight, have to disinfect it soon (bird stuff), as summers gone, may leave it till next year. ;) or it depends on the weather changing to summer part deux.
Oh and this is a ship of the line don't you know, we hang pirates from the yard arm.