HI Dave
It's good to know I'm not alone with those!
Edward

HI Edward
I think I may have misunderstood. if you were referring to the bulb at the bottom then your sizes would be OK.
One of my senior moments.
Dave

HI Edward
Not sure if you have given the correct measurements. Did you mean 30cm (300mm) and 8mm?
Glad to hear you are progressing. Hope you will post a few pics?
Dave

HI Dave

I think it's time to get cutting! I think I will make the stem about 30mm deep. I have some 80mm dia plastic tubing and I can turn the end caps from ply glued up to suit.

Hard luck with the sailing. Better luck next time!

All the best

Edward

HI Edward
The 8mm studding was used as it was easily available. You could use thinner, especially if you are using two studs, and if this goes into a metal sleeve it will provide sufficient support for the keel if you use my method of providing a lip on the keel to match with the hull. You can add wood to the inside of the keel where the studs enter and this will make a very solid and stable mount.
Glad to have helped, I wasted much time with my original keel. You will need to plan how big you make your keel. it is important you resist making it too long to avoid the steering problem. You can probably make the bulb a bit fatter which will help your larger sails stay upright.

Although Brian made a mould he was using for several similar models, for a single model I would be tempted to make out of sheet lead held together with nails with the studs well affixed and covered with cloth tape to see how it works. When you are happy you can then fibreglass all over and make a proper job.

Sailing was disappointing as the wind was swirling all over the lake. At least I wasn't the only one affected and the rain kept off. thank you.
Cheers
Dave

Thanks Dave. I hope the sailing went well.

Your schooner's keel is similar to what I was planning for Cariad, only wider. However, with the potential steering problems and the fact that the rudder does not travel either side very much has left me now proposing to make a bulb type keel, as you have suggested. So thank you.

I am proposing to fix it with a thin length of studding through a stainless tube. I reckon on the studding being in tension and the keel being firmly in place should be OK. My problem is that the keel is only 12mm wide.

Edward

HI Edward
I have now done the measurements.
Weight 5.3kg
Length at keel 235mm at base 220mm
depth at front 200mm at rear 185mm
Bulb at base 50mm diameter, depth from base 70mm
At keel width 30mm recess round keel 30mm
Bulb is a gentle curve from 70mm above the base to the keel with a min width of 20mm.
All measurements are outside diameter.
If you draw a sketch and compare with the pics it should become clearer.
I mentioned my schooner keel and attach a couple of pics of the attached keel and the handle inside . This is a 5' model and the keel is 18kg. it is different keel shape to the Cariad and carries massive sails so probably requires more weight.
Hope this helps. Please ask if you need more info/help
Just off sailing, nice and windy so tyhe RG 65 should really skate. Just hope the rain keep off.
Dave 😀

Thanks Dave.

HI Edward
I believe they were 8mm but will confirm tomorrow. From memory my weight was 6kg so I expect you may require double this but you already know how much fro you test. I did have to add about a kilo to the front on completion to balance correctly. Not a bad thing as it is difficult to remove weight and you can balance the boat by adding weight in the correct place. I had forgotten you had a larger model and suggest you place two studs under the hatch and attach a handle to carry.
Dave

HI Dave,
My hull is plank on frame and built at twice scale. The hull was from eBay so I can not claim any credit for this but it does mean having to work around someone else's ideas.
What diameter studs have you used?
Edward

HI Edward
I will measure my keel tomorrow. I can understand your concern but my keel is clamped tight around and against the hull/keel so will actually strengthen your keel. I bent my stud thro 90deg where it is encapsulated in the lead and resin.
My hull is fibreglass and I note yours appears to be lined so will be quite strong enough to support the keel. I did mention you would need to provide support across the hull at the top of your post and a fibreglass bandage at the base will help transfer the load.
I and my fellow club members have used this system for the last few years and have never had any problems. I am building a 5' plank on frame schooner ( this will be the 5th in the club) at present and this has an attached keel which does use two studs but it is much longer and I use the studs inside to attach a handle to carry the model. The keel is permanently attached.
Yachts are great fun but they can be heavy. We now try and attach a lifting handle inside the hull beneath a removable hatch, or attach a couple of eyes above deck to allow for a lifting handle.
I will post the weight and measurement and stud details tomorrow.
Dave

Sure will, but don't hold your breath!

I hope you will post some photos as it takes shape, and of course, the launching 😊

Yes, it's big! I expect I'll need help launching and recovering. But that is another subject...

According to my calculations 14Kg lead would have a volume of app 1250cc. ( 1234.35 cc).

This is a LUMP!!

if you start out with some sample ideas so the keel is say 30cm long x 3cm thick it is 14cm deep.

Rather than a single threaded post you should consider 2 or 3 so the load is spread. Also the interior of the hull needs re-enforcements to spread the load out.

I can see this model doubling as a weight training exercise!!!!

HI Dave

I'm not sure how much help the dimension would be but its better to have something, than not! So yes please. My worry is the horizontal forces and the effect on the keel, which is made from 12mm thick mahogany. I would have thought that the threaded rod would need to be at least M4, possibly M6, so the sides of the keel would need strengthening, I would have thought.

Edward

HI Edward
If you look at the last pic I posted you can see a big block of wood just aft of the mast with an aluminium tube opening showing at the top. The threaded stud (B&Q) goes thro this with the washer (nylon) and nut on top.
My mast is tensioned by a spring at the base and the pin thro the mast can also be seen. The spring connects to the fore sails and replaces the servo I had originally installed.

Looking at your model I suspect you will be able to use the same location, possibly with a less substantial piece of wood and some cross bracing.

The keel is heavy and you will need to have a solid fixing to avoid movement when fitting and removing. There is only downward force when fitted as the moulding is fitted along and both sides of the original keel.

You need to have the fastening above the horizontal waterline to avoid water ingress. I use an "O" ring at the bottom of the stud and you can make a good job with silicon sealant on the keel to improve the joint. I have had no leakage and the nylon washer both seals and spreads the load.

If you need any dimensions for the keel please let me know.

I hope this helps
Dave

Looks a nice model! I am interested about her not being steerable with a full length false keel; not something I need at all! Where along the hull did you find the keel went through? I may have to redesign my R/C arrangements.

Edward

HI cenbeth
I did a build blog on my Cariad http://mdlbt.com/10203 and this may help you with your ballast.
I originally tried lead inside the keel but the model blew over in all but the lightest of breezes. Chris Brown manages to sail his models with this arrangement but our lake is a vast open expanse and can experience some very rough weather.
My first attempt was to place a false keel along the length of the boat attached with bolts, but this acted as a rudder and made the model almost impossible to steer.
Others in my club had used fibreglass moulds for detachable keels and this is what I now use. There is a picture of the keel in front of my model on the blog and I have added a couple to this post.
The lead is cut into small pieces and rammed into the casting with a piece of studding added to allow for bolting to the keel inside the model on a lump of wood above the waterline. The moulding fixes snugly to either side of the keel. The lead is fixed in place with resin poured over the lead. I undo the bolt on the studding and the keel can then be removed from the hull. Makes it much easier to handle and is less prone to damage.
If you are familiar with casting and are keen to cast I would use a male mould with casting sand well compressed in a box.
I believe the fibreglass mould will be a simpler solution.
Be interesting to see how you progress
Good luck
Dave

I'm a bit off from the actual lead casting at the moment. I still have to finish off the first female mould to check the profiles against the hull shape.

A commercial foundry will probably want to sand cast. Unless you can find one that does lost wax ( arty stuff) hummmmm I just remembered something

http://www.tomps.com/heat-resistant-rtv-silicone-rubber-to-5kg-kits-p-501.html

Have a look at that much less of a problem than plaster.

You will have to make some kind of pattern if you use a commercial company. Have a look on youtube for a how to.

I figure a search will find casters someplace near you.

http://www.bronzefoundry.co.uk/CONTACT/CONTACT.html

Yes, to all of it! That is why I'm thinking of trying to find a commercial company who would be able to help. But in North Wales???!

Making a big mould out of plaster of Paris worries me! Remember the mass of metal your playing with and consider the mechanical stresses involved. At the very least consider incorporating metal mesh to support the plaster.

Drying that amount of plaster is going to take quite a while grins at least you know what will happen if you don't.

I'm using standard roofer's flashing as the source for my lead. I could just cut it up and bolt it to the sides of the keel but with the amount needed it would look stupid! I could mount it internally but I want the lead to give a bit of stiffness to the boat so it needs to be as low as possible.

I worked out the amount of lead I would need by floating the boat in the bath and adding weights until she was at the waterline. I then weighed the weights.

Currently I am making a mould for a female hull shape in Plaster of Paris. I will use this to get an accurate shape of the hull. This mould is in two parts. I then plan to make a male mould and cast it upside down so the top of the mould will be at the bottom of the boat. My thinking is that I am not quite sure how big it will all be and it can find its own level during the casting.

Years ago I cast a bulb keel for a 10 Rater. This was in Plaster of Paris mould and worked out fine. its weight was significantly less though, I think about 5kg. Having used Plaster of Paris I am mindfull to stick with it, the important thing here is to ensure it is properly set and dried out COMPLETELY. I agree whole heartedly about the need for safety equipment and feel I should find a commercial caster. I have had a mould go up on me once, without serious damage. it was seriously spectacular as you say!

If your melting (and casting) that much lead your going to need quite a lot of heat and best done outside.

You also need to consider how your going to pick up and pour such a weight of liquid metal.

if you NEED 14KG of lead for ballast then you will need around 20KG of liquid lead to allow a decent sized casting gate so your finished casting doesn't shrink to badly away from your mould.

I would figure it to be a 2 man job. Have a hunt around youtube for foundry work and see how they handle casting.

What are you going to do for a mould. For such a large casting it will need to be 2 part and have a runner and riser the riser having a large casting gate built in.

Take precautions full face visor leather gloves and a heavy apron are a MUST.

if you have never seen water and liquid lead come together trust me the results are spectacular and best not experienced at first hand.

You need to make a pattern ( for sand casting ) oversize so when your casting cools its the right size. Sand casting is probably your best bet.

HI Edward, Won't standard roofing lead be ok for ballast? it can be cut with sturdy scissors and shaped to fit...

HI Dave,

My mast is removable too. I have a screw to act as a jack so that it all tightens up. The rigging has stainless ste?l hooks.

The receiver is on a pedestal. it's about 2" tall so as to be above the waterline. I'm hoping it will be high enough but until it's on the water I will not know. I have to make a false lead keel first though. I need to melt some 14kg of lead to bring it down to the waterline and I'm not sure how the best method would be. I've melted lead before but not on this scale!

Edward

HI cenbeth
All looks very neat and shipshape. 😀
My Cariad has but one drum winch, rudder servo motor and ESC. I use the Mtronic switch to power on and off. The battery plugs directly into the Esc which powers the receiver and servos. I did have a sail arm servo for the jib sails but find the model sails just as well using a sliding bar across the front deck adjustable by bowsies. My mast is removable but I can fit fully rigged in my car.
2.4Ghz rx need to have the aerial above the water level and my rx sits on a ledge just below the rear cabin with the aerial leads actually in the cabin.
In the earlier pics your rx was low down in the hull and you may need to raise the aerials to avoid loss of signal, especially when the boat heels.
It would be good to see a pic of the whole model, possibly sailing?
Dave

I've not quite finished yet but attached are photos of the storey to date. I've bundled up the servo leads together, put them inside some spiral wrap and tied them to a timber strip alongside the hull frames. I liked the idea of gluing them in place but decided that I didn't want a permanent fit. I haven't dismissed the ferrite beads but decided I would try it without to start with and see how I got on. Thanks everyone who responded, you have all been a great help.

The power cables have been routed along the other side of the hull. Each pair has some spiral wrap but I am trying to work out a neat way of mounting them. The problem as I see it is that the main board (holding the motor, speed controller and receiver) is removable and I want to keep it that way.

The power cables go to a bus bar arrangement. This is made from some copper sheet (actually remedial roof-slate clips/ties) which I have cut up and silver soldered lugs on the side. There are two of them, ve and 've, separated by a tufnol strip and fixed together using nylon bolts.

Thanks, I think I understand!

sorry but yes it would HOWEVER join them dry and use tape should be ok what's important is that current should be able to flow through the ring.

I can go into the theory if you want but its not simple or obvious. What your trying to create is a situation where AC signals "see" a high impedance without creating higher DC resistance.

While I say a bead you could achieve the same effect by winding the lead around a piece of ferrite rod. A bead is just simpler to keep in place.

Thanks for this. I have had a quick look at the Maplin site and notice that split rings are made. Would this mean a smaller ring could be used or would any glue used to join the halls would interfere?

Other than a tiny weight increase no.

http://www.ebay.co.uk/itm/ANTI-PARASITIC-3B1-FERRITE-BEADS-FERROXCUBE-QTY-10-PHILIPS-FX1115-x10-blb8-/121077629391

One example.

http://www.maplin.co.uk/search?text=ferrite beads&x=0&y=0

Another source.

Thanks for that. Where do you get them from? it seems to me that it should be fairly simple to fit, and hopefully cheap, and a benifit of cleaner operation. Are there any down sides?

It would be best to take off the plug and use one bead per conductor. Thus each servo lead needs 3 beads.

However a bead with a big enough hole to take the plug and just have a single bead per servo is better than nothing.

Most of the time, the occasional glitch is something you can probably live with.

Does this mean taking off the plug so it can be attached or should the hole be big enough to take the plug?

In a perfect world you would have a bead on each conductor of a servo lead. The conductor should pass through the bead loop over and pass through again to make a single loop coil.

So you need a bead with a hole big enough to allow that.

it needs to be at the receiver end not servo end.

I've never heard of these so looked on eBay. What size would you use and how many are needed?
Edward

If your running long leads for servos get some anti-parasitic beads. Don't forget every servo lead connects to the receiver, they also act as aerials so feed signals.

Some will see this as overkill and most of the time it is BUT when you have a lot of electrical noise in a model using them can well reduce the number of glitches.

You are certainly giving me some ideas and food for thought, thank you. I will report back on my final solution, good or bad!

Edward

fix some plastic trunking down the length of the boat:

http://www.ebay.co.uk/sch/i.html?_odkw=plastic trunking -trunk&sop=15&osacat=0&from=R40&trksid=p2045573.m570.l1313.TR4.TRC2.A0.H0.Xplastic trunking pvc.TRS0&nkw=plastic trunking pvc&sacat=0

run the servo and any other wires into and out of this, cutting side holes as required. As Derek says above, you will probably need some servo extensions.

My humble offering is to use a hot glue gun to hold cables in place as it can be released and refixed. Route all cables to the side and make all turns right angles, fix cables into bundles with cotton ties till satisfied then glue. Finally do as I say not as I do!!!
Roger

Ignore my last post, I was thinking of wiring from scratch. But of course servo's all have leads attached. However I tidy mine a bit by buying servo extension leads from eBay so that all servo cables go straight to the side of the hull and run down there. Tack with super glue as its unlightly they'll need to come out again.

I have used ribbon cable before. Used a bit like a wiring loom, needs planning though.

Vic Marcham of the Mablethorpe Model Boat Group on here may well be able to advise you. He has a great deal of experience in that field.
Peter