Model Boat Mayhem

Dry Dock / Shipyard: Builds & Questions => Yachts and Sail => Topic started by: BJH on March 28, 2008, 12:23:30 PM

Title: Lucia semi-Scale Footy build description.
Post by: BJH on March 28, 2008, 12:23:30 PM
The main area that interests me in model boating is Scale Sail and so a few years ago (early 2005) I bought a GRP hull from Mike Mayhew  (AKA Waverly models)  of a Morcambe Bay Prawner as my first project. This lay on a shelf in my garage for a few years until I found the time to start on this project in June of last year (2007). I made fair progress with this but ran into a few problems with this (mainly in planning how to transport the finished model and how much mast and bowsprit de-rigging would be needed to get it into my car). This caused me to start thinking that a simpler smaller project would be perhaps allow me to get something on the water for the summer of 2008, and allow me to improve my model making skills before returning to larger projects. I wanted something small that would easily fit in the car boot with out any de-rigging, not take to long to build, but yet looked interesting on the water.

I had seen on the internet and was following the interest in footies and came across a photo of a gaff rigged footy on the web site designed by Richard Web called “Wonder”. I also saw this model on a stand at the Southern Model Air show and on Richard Web’s Website and hence I decided this might be an interesting project to become side tracked onto. After a bit more research I found I could buy a kit from the designer to construct this in styrene and that the plan had been included in the December 2006 issue of the “Model Boat” magazine. I decided that I would prefer to build in plywood instead of styrene and so obtain a back issue of the magazine.

The information contained in the magazine consists of an 820 mm x 590mm single sheet full sized plan (with half scale hull panels) and a 3˝ page article with 21 colour photos and describes how to build the model in styrene.  I knew from some discussion I had picked up on the Net that the model was in fact slightly to large a beam to fit into a footy gauge box and so I decided that although I didn’t imagine I would be entering any races I might as well try to modify the design such that it would be footy legal if I ever changed my mind. (After all someone has to come last in any race, and I may be able to take the prize for the heaviest and slowest footy around).  So with the aid of a number of photo copies of bits of the plan and some cardboard and a few iterations I managed to come up with a modified plan that had a slightly reduced beam of 150 mm. (I have since realised that I have stuck 3mm wide rubbing strakes to either side of the hull so the beam is now approximately 157mm, so much for good intentions!)

The 7 hull panels were cut from 0.8mm thick ply and taped together to form the basic hull shape. Internally  a number of small triangular pieces of  3mm plywood were glued between the hull panels along with various small bits of softwood timber.  A centre bulwark of 3mm plywood was added to support the  forward end of the internal radio deck and a strip of softwood glued to the inside of the transom to support the aft edge. The joins between the hull panels were then secured with a fillet of two part epoxy and a blob of plastic padding at the bows where the points of the hull panels come together. (some of these details can be seen in photo 1.)
Title: Re: Lucia semi-Scale Footy build description.
Post by: BJH on March 28, 2008, 12:27:51 PM
During the build process I treated each of the pieces of timber with wood preservative a number of times to protect the timber from any future problems. The external keel was cut from 5mm plywood, and included 3 lugs that fitted into holes cut in the hull, and a slot in the centre to allow a fin to take the ballast bulb to be fitted. A long 3mm stainless steel screw was fitted through another piece of 3m plywood glued to the centre bulwark and down through the hull and epoxy’ed into a hole drilled into the keel. This was intended to help support the keel from moving from side to side .

A small piece of softwood was then glued to the bows as a stem post. Internally a number of small pieces of plywood and softwood were glued in to support the deck and to reinforce the hull to allow brass eyes to be fitted for the rudder pintle’s and the bowsprit stays. Two small 1mm thick Aluminium plates were fitted into rebates around the slot in the 5mm plywood keel such that a 3mm wide recess was generated to allow the fin to be slotted in and secured. Two slots allow slight adjustment fore and aft of the ballast bulb. (This can be seen in the photo’s 2 and 3.) . The rudder was cut from 5mm ply and the tiller arm made from a small piece of American walnut. (photo’s 10 and 11).

The radio deck and the deck were cut from 3mm plywood (photo’s 4 and 6) and planking lines added to the deck with a black pen. The servo’s used are both Futaba S3003, with the sail control servo having a sail arm made from 1mm aluminium bolted onto the standard servo arm. The receiver is a Futaba R152JE and this and the battery pack sit in trays made of 0.8mm plywood. A miniature toggle switch completes the electrics. It was intended that all these components would be easily removed from the boat.

Mast and spars were made from 6 and 9mm diameter dowels from B&Q, make sure you pick ones without finger joints in them. ( Photo 12). The mast was tapered by first planning using a simple jig, and then sanded round using a cordless drive and sand paper. 

At various points during the build flotation test were carried out. The early tests indicated I should be working towards a total mass of about 1200gms to achieve the waterline shown on the plan. The bare hull was around 200gms, the masts spars, rudder, deck, etc was around 160gms, and the radio deck (plywood deck, 2 servos, receiver, switch wires and batteries) was around 220gms. This came to a total of around 580gms.

This meant I needed a fin and bulb of approximately 600gms.  I thus constructed the fin and bulb assembly shown in photo 7 which came in at around 540gms.  As I didn’t fancy the idea of playing with molten lead this was done by rolling lead flashing into cylinders and using this to pack out the aluminium tube. This was compacted as much as possible by hammering. The ends of the bulb were made out of maple, with as much of the centre of each drilled out and replaced with more lead flashing gently hammered in. The fin was a piece of 3mm aluminium plate that fits into the tube through slots top and bottom and secured with a 3mm bolt and epoxy. The completed assembly was then finished with plastic padding and sanded fair. At the tube end of the fin I added another piece of aluminium bar 5mm square which has a slot cut in it to allow the tongue of the fin to go through it, this was secure to the fin with 2mm machine screw and epoxy. The completed assembly fit into the keel slot described previously and is secured by two 3mm pan head machine screws.

Further floatation tests lead me to believe that to achieve the waterline shown on the plan I needed to be working towards a total mass in fact of 1500gms. I thus decided increase the mass of the fin and bulb assembly by another 350gms, as I was to lazy to start again from scratch, which is why the finished item shown in photo 8 is a somewhat strange shape. This was done by adding more bits of lead flashing inside an aluminium shell to the top of the bulb. The modified bulb and fin now comes in at around 890gms which is about 60% of the total mass of the model.
Title: Re: Lucia semi-Scale Footy build description.
Post by: BJH on March 28, 2008, 12:30:50 PM
The flotation test shown in photo 9 shows the deck and mast fitted, The mast is secured through the deck and into a small block of softwood glued to the inside of the base of the hull. The photo shows a number of brass fittings, these were all made from brass rod and held in place with epoxy. The bowsprit has a brass P clip made from sheet brass which is bolted to the stem post with a 2mm bolt, and held at the deck end with another small piece of American walnut. The deck cover shown in photo 11 was made from 0.8 mm plywood and slots over a 0.8mm plywood coming glued inside the deck opening. This was then stained and varnished.

The hull was painted using halfords spray paint, grey and red primer, and galaxy blue left over from repairs to a dent in a previous car. The water line stripe, rubbing strake stripe, and the lettering (15mm and 6mm) are from Barry’s model lettering. The model was then finished with 3 coat of Ronseal Diamond hard matt polyurethane interior varnish.

The standing rigging was in 7 strand Nylon coated 0.018” Stainless steel wire from Hobbycraft (bead stringing wire 20lb breaking strength). The running rigging was old kite string dyed with wood stain.   

Photos 13 to 19 show the model finished with all but the sails. I decided to name her after my 2 year old half Spanish granddaughter, so the name Lucia should be pronounced with the Spanish c sound. I decided to “ register” the boat in Faversham as my parents live near there. The stand is made from varnished softwood.

At this stage paper patterns of the sails were made and checked against the mast and spars and then adjusted as necessary. The total sail area of the sails is around 1238sq cms (which is about 1/8 sq metre).
The sails are made from bits of old sheets stolen from my wife’s scrap material bag. A number of bit were dyed using dylon cold water dye (Koala brown). It turned out that one of the bits was I suspect pure cotton and the other bits poly-cotton, which resulted in one piece turning out much darker than the others. I decided to take advantage of this occurrence by using the darker piece for the jib, with the lighter bits for the fore sail and main sail, and an un-dyed piece for the topsail.  Using the paper patterns the cloth was marked out with a soft pencil, and then allowance made for a double 3mm seam all round. The cloth was then cut and the hems folded and ironed, using a domestic dry iron and a thin steel ruler. The sails were then stitched using a hand operated sewing machine and a small amount of hand sewing. Finally small eyelets from Sailsetc were added to each of the four sails. The sails were then fitted in place using dyed kite string, with the knots “sealed” with a small blob of superglue. The mainsail sheet is attached internally to the mast, then passes through a loop on the sail arm and out through the deck via a small brass tube next to the mast. It then passes up to a brass eye on the mast just below the boom, then along the boom to another eye, and then down to the horse. The fore sails have a sheet from the deck fixings for the standing rigging through an eye in the sail and on the matching deck fixing on the other side. Small bowsies were made from sheet brass to adjust these sheets. Photos 20 to 25 show the model with the sails fitted.
Facts and figures.

Weight of boat        1.57kg 
Weight of stand       610gms

Total height of boat on stand    850 mm
Bowsprit end to boom end        560 mm
Maximum beam                 157 mm
Mast height from deck   440 mm
Top of topsail spar to deck   575 mm
Bowsprit end to stem      165 mm
Stem to transom      310 mm
Boom length         260 mm
Bowsprit length      270 mm
Topsail spar length      225 mm

Servos - 2 off Futaba S3003
Receiver – Futaba R152JE

The model is now finished and awaiting her maiden voyage. I plan to join a local club, but am tempted to try to get a bit of private practise in first so that I don’t look too much of a hopeless begineer to experienced sailors.

Title: Re: Lucia semi-Scale Footy build description.
Post by: BJH on March 28, 2008, 12:32:22 PM
Last few photos
Title: Re: Lucia semi-Scale Footy build description.
Post by: BJH on April 15, 2008, 03:28:39 PM
Update on the maiden voyage.

I took the opportunity to try the boat out on a quiet sunny Friday afternoon (4th April) at the local boating pool. On the plus side it didn’t actually sink and looked OK on the water. On the minus side, control was marginal to say the least, it actually moved quite well when the wind caught the sails, but steering was not very effective and the mainsail sheet did not seem to let the sail out very well.

I had previously had some reservations about the amount of rudder movement and how crude the design of the linkage was. This failed after a while and brought the trial to an early end.

Problems noted were:-

The bowsprit had moved, causing the forestay to slacken.
The rudder linkage failed, due to a M2.5 screw loosening inside the hull. I suspect the angle of rudder movement not perhaps being enough along with the rudder area not being large enough resulted in my inability to control the heading of the craft.
The main Sheet did not seem to let out very well, I think due to too much friction in the brass tube bringing the sheet through 90 degrees and up through the deck and the two eyes on the mast and boom.

Back to the Bench to try to improve these areas.

The bowsprit was restored to its original position to tighten up the standing rigging, a hole drilled in the walnut block through the bowsprit and a section of brass rod inserted to prevent any further movement.

I took the decision to re-engineer the rudder linkage completely rather than to try to make the original design shown on the plans work more effectively. This I did by replacing the system shown on the plans, with a more substantial system. Unfortunately the new system has ended up more complicated than I would perhaps have liked, with two linkage rods (one below deck, one above) rather than the more normal one. However the new system seems to work reasonably well and I think is much more robust, and less “sloppy” than the previous one. The rudder throw angle is now 35 degrees both ways, which I believe is generally thought to be OK.

I have also taken the decision to try an extension on the bottom of the rudder. This has been made from a small bit of clear 3mm thick plastic (40mm high and 75mm long) mounted onto the bottom edge of the rudder using some brass sheet and M2 nuts and bolts.

I have yet to find a solution to the amount of friction in the main sheet. I have tried plenty of wax on the line but I don’t think this has made enough difference yet. The diagram show the current arrangement. The main sheet is tied to the mast at point A, and then is routed through a loop on the sail arm servo B, then via bent brass tube C up through the deck, then up the mast to eye D, along under the boom to eye E, and then down to the centre of the horse F. I suspect the problem is there are just to many friction points, with the eyes D and E being the major culprits.

I would appreciate any ideas on how to improve the existing system. I don’t think I can do any drastic changes to eliminate any of the friction points but would like to try to improve the Eyes at D & E.
Title: Re: Lucia semi-Scale Footy build description.
Post by: Big Ada on April 15, 2008, 05:00:58 PM
Why not come from winch arm then up through deck at F then to E cutting out several sharp angles.
I made a styrene Ricky webb Footy, you wont come last, thats the position I finish in!.
Kite line seema a bit thick, you could try button thread or fishing line.

Title: Re: Lucia semi-Scale Footy build description.
Post by: BJH on April 17, 2008, 12:41:27 PM

I replaced the main sheet  with 7lb fishing line last night, and that seemed to be dramatically better. I  now just need to carry out further "sea trials" when I get the chance. Hopefully I will try to get some photo's then of it under way.  I just need to get my Ł5 million  Public Liability Insurance sorted out so I am covered in case someone attempts to swallow it by mistake and chokes to death ( Hard to imagine any other way I could injury anybody!).

Title: Re: Lucia semi-Scale Footy build description.
Post by: andrewh on April 17, 2008, 01:04:58 PM

Lovely boat and craftsmanship  - thanks for sharing it with us

Sorry I haven't dived in before, but you seem to have it all under control ;D

Your mainsheet challenge stems, as you know, from the long and scaleish run of the sheet - I'm glad that you have improved the working with lighter line. 

I guess your servo will pull the sail in quite smartly, but loosening the sheet will be a bit imprecise (since there is not much force pulling the sheet out thru the tube and eyes.  You could attach a length of elastic (pole elastic from a fishing shop) to pull the sheet right out so it is working with the wind.  The servo will work against it, but the elastic is very light and not an issue for the servo.

You have a VAST long servo arm and doubler tackle  travel because you have the sheet taken to the end of the boom.  If this is for scale reasons, this is great, but my preference is for a doublesided arm, preferably without doubling tackle so that one side of the arm pulls the jibs neatly and the other has a good pull at the main boom.
 I will happily admit that with the main horse where it is it will not be very easy to get a scale-like connection to the boom

I will attempt to sketch the elastic attachment - its a thing that can be tried with just an opened rubber band and some insulating tape!
Title: Re: Lucia semi-Scale Footy build description.
Post by: BJH on May 07, 2008, 02:26:10 PM

Here is a photo of the above deck part of the new rudder linkage, and also the plastic rudder extension.

Title: Re: Lucia semi-Scale Footy build description.
Post by: BJH on May 07, 2008, 02:30:38 PM
I had the chance to carry out further “sea trials” at the Southwater Dabblers home lake last Friday afternoon (I am lucky enough to finish work at 1.00 p.m. on Fridays). I was in general very pleased with the boat, conditions were fine and the sun was shinning. The wind was fair, any more would have been a problem, and I don’t think I would have liked any larger waves when sailing such a small boat.  I sailed the boat for around an hour on and off, and found I was able to navigate a course around a small section of the lake OK. This is only the second outing for “Lucia” and I have not sailed any other boat before so I was reasonably pleased. I did find that I had to watch carefully for any tendency for the bows to dip down to much and ship water onto the deck. I found that once on the deck water did not flow away, but this was fairly predictable as I should have cut some ports in the 3mm high gunwales. I did find at the end of play that I had a small amount of water in the boat, say about a teaspoon full, and have not really worked out how this happened yet. I don’t think it got in through the hatch. The mainsail sheet is fishing line feed through a very small diameter brass tube, which seems unlikely to let much water in. The rudder linkage may be the main suspect but I thought I put enough grease on this to solve this. All in all, a mystery at this stage, but I will monitor this in the future. I meant to take some photos on the water, but am not up to sailing and taking photos at the same time yet!

I was very pleased with the comments that I received from the handful of club members at the lake last Friday, the look of the boat (if not my sailing) seemed to be admired!

So what have I learnt during the build of this boat:-

1)   I should not slavishly follow plans, but have more faith in my own engineering judgement. I am in particular thinking of the rudder linkage problems  I  experienced on this build. I will in future try to slightly “over engineer” rudder linkages and try to keep everything as simple as is possible.

2)   I do not think a solid radio deck is a good idea. I will next time make sure I can see to the lowest part of the hull so that I can easily see, and hence  remove any water that gets into the bottom of the boat.

3)   I will make sure that sail control sheets are routed as simply as possible to reduce friction in the lines.

4)   Assume that water will get onto the deck, and make sure that there is a route for it to get off again.

So what next then ?  It has to be another Footy.   On the Footy web site, , on the plans page are downloadable plans for the Cobra Mk 1 hull designed by Bill Hagerup. So this is the next project then, I will use this hull design and build a semi scale Gaff rigged footy  to sail with “Lucia”. The plans state a displacement of 450gms, I have no hope of building as light as this, but will try to aim for approximately half the weight of “Lucia” say 700 to 750 gms. But more details perhaps for another day.

Title: Re: Lucia semi-Scale Footy build description.
Post by: andrewh on May 07, 2008, 03:44:48 PM
Glad the second sail went well - indeed it must look very pleasing on the water O0

There is a cheerful band of Footyers who go for scaleish looks and the indefinable "charm" in a boat*.  This would have to include the certifiably "distinct" characters who build square-riggers to footy rules.

They may not get the fun component of winning (though any sorted boat will have a chance of being there or thereabouts) but there is a lot of pleasure in contemplation and style, too!  Have you seen George Turner's Freya?

I am glad that you have discovered the rcsailing site.  Have you delved into the discussion groups?
There is an enormous anmount of help, encouragement and applause available

Not sure where you are based (must be around London). 
There is a meeting scheduled for this Saturday at Bournville boating lake, and you would be welcomed with open arms if you turned up with Lucia
No formality, no stuffiness (I pray)

Bill's Cobra is a nice hull, and a good development of his Razor.  When I saw the plan I was strongly reminded of Wonder (without the long keel).  It builds well in any sheet material - so everyone can use what suits them (my razor is 1mm styrene)

Please keep us up to date with your progress


*there is one nameless Footyer (I won't mention your name Firstfooty) who combines winning performance with planked craftsmanship.

Title: Re: Lucia semi-Scale Footy build description.
Post by: BJH on May 20, 2008, 12:52:24 PM

I am now a member of the Southwater Dabblers MBC who are based just south of Horsham in West Sussex. I went for a sail ( well a drift really - hardly any wind) last Friday afternoon and took a few not very good photos of "Lucia" on the  water.