Looking very straight and clean.
A good starting will lead to a fantastic finish.
😎

Hi Duncan motors look OK. Are you running on 7.2 volts?

Winch is good.
I think the keel area should be something like 3 x 8 inches. with about 32 ounces of lead as the weight.

You will have a little extra displacement with the additional buoyancy of the keel as described before.

The keel top should be exactly straight and fit flush and dead straight downwards to the hull. You should clamp it in place quite tightly as well.

I have a similar system in a much larger yacht and it works well.
Roy

Hi Duncan I was proposing to cut the keel all the way through twice for each steel tube and put a another piece of 3mm ply each side and use CA glue to secure each tube. The wood keel can be a bit wider here it won't notice and it will give a slightly wider base for the keel to be clamped up to as well.
On reflection I think I would make the keel first and then the tubes can be lined up where the go in the keel.

A wider keel than say a piece of aluminium wil flow through the water with less disturbance. The keel cross section should be an aerofoil shape. This is because the wind will mainly be coming from the side so the yacht is crabbing across the water.

That is a rounded but sharp front and the widest part one third along and then taper to the end.
Look up aerofoils wing sections for shape take the top surface and do the bottom surface the same.

To locate a shaft in the keel so it does not turn when the nuts are fitted on to clamp it in position can either be drilled through and a stiff wire inserted or bend the shaft and allow the space for this at the centre of the keel.
Make the keel in layers a central one of say 3mm and then layers each side of 1mm untill you are 7 or 9mms wide.
Glue the wood with PVA and then clamp everything together in a vice or screw down clamps and essential it is flat. When dry it will be very stiff.

When filing or sanding to give the aerofoil section you will see the other layers appear like contours. These give a guide to getting things even. See photo. this is a rudder the shaft is bent inside to secure it, the post cannot twist inside.

Clamping gives a strength 10 times more than just spring type clips, perhaps use spare wood that will take any marking from the clamp but it must be over the entire surface. Leave for at least 24 hours, while clamping you should squeezing out glue until you can clamp no more.

I have a disc sander and I find it very enjoyable seeing the shape take place and with the contour system you do not need a template.

The weight at the bottom may best be attached by screwing it on as you can't glue lead. Keep it as close to streamlined as possible as water is nearly 800 times more dense than air.

Hope this helps.
Roy

Hi Roy,
Your idea seems to be a much better one than just bolting on the extended keel to the existing keel supplied in the kit. Your idea got me thinking and I remembered that left over from my Riva Aquarama kit were the prop tubes and prop shafts supplied in the kit for if you were building a display model. I've dug them out and I think they might be a perfect fit. The prop shafts are 24cm (9.5") long and the brass tubes are 10cm (almost 4") and the tube diameter seems to be about 4mm+ and the wood is 5mm. I can't find my callipers but the brass tube appears to be just slightly thinner in diameter than the wooden keel - which can't be a bad thing as the epoxy glue will fill the gap. It feels a bit scary cutting the keel in half in two places but I'm sure with strengthening on either side it will be fine! I will have to ensure the keel is still the same length after fitting the tubes! I will need to think about how to do the lateral support at the top of the tubes because I think the cuts in the keel will have to be half way between the two ribs. So will the strengthening have to attach to the side planking? What do you think? The photo shows a sample of the keel thickness with the tubes along side. Not sure how I will be able to drill a long enough hole into the wooden keel. I will think I will need a hole deeper than 50mm (2") or do you believe this will be deep enough?

I had previously bought two of the motors in the photo and also one sail winch from Howes models. I think the winch is probably the one you have mentioned above working with 4 turns. Do you think we can manage with one winch for the 3 sails?

Your keel suggestion came just in time before I started to glue up the ribs!! Thank you!😊

Hi Duncan well done nice to see you have the kit and have started.
I have been thinking about the build especially the conversion to sail.
Here are my current thoughts, first it will be a wood keel.

I want to bury two either very long screws or some studding in the removable keel. I have been thinking two screwed rods (machine threads) that will fit into 2 tubes laid up in the keel. The tubes should rise about 2 inches into the hull and be firmly located especially across the beam.

I think this is the least change to the hull building. Cuts made in keel to take 2 sections out and tubes inserted and side braces keeping the keel in shape.

I am guessing to put the keel in the centre of the underwater section. There will also need to be an extension on the rudder or maybe a replacement one for sailing.

The keel will slide into the tubes and then nuts will hold it in place. When operating on engine, blocking the top of the tubes will keep ouy any water coming up the tubes.
I have finally paired a couple of motors and a couple of options as well.

I think the easiest approach to a sail winch is an enclosed drum winch 4 turns about a tenner from Howes of Oxford.

I think I have worked out the electronics to disable mixing when the rudder is in use and the sails are doing the driving.

Would like to hear your thoughts on the above.

Regards
Roy

H i Duncan all good stuff you have ordered and will all fit together.

If you want more advice I do need to know how many channels your radio has.

The 2 esc's will plug into the mixer and that will give you a single control on the transmitter for both of the motors to run.
Check which o/p is which. So left rudder slows down the port motor. You can share the power battery with the 2 esc's. Remember to cut one red wire in one of the esc's servo leads.

The single line from the mixer goes into the signal wire in the socket end of one Y lead tail and the rudder servo lead goes in the other, then the Y lead goes into the rudder socket on the receiver.

You can do all this with a standard 4 channel RC set. Left hand up/down to throttle. Right hand up/down to winch, remember to set it so that when tx. stick is fully away from you the sails are out. Right hand left/right is the rudder.
I should not complicate it further. There is no diagram needed.

Relax and enjoy the build.

I am just making a second sail set, this will give me 2 options, on my Gracia and it does not matter how high or low I put the yacht my back still aches! If it all works I will photograph the yacht and put it into My Harbour.
Roy

Hi Duncan I got your PM. Before you go any further, how many radio channels will you have to control your Bruma?

regards
Roy

Hi Duncan I have bought some small magnetic plunger switches. There is one part to fit in the deck, and the other just shorts out the contacts.

It is held in place by a pair of tiny magnets, switch is 20mms long x 7 mms wide, good way of switching off the power at the BEC by removing the contact.
I thought built in to a deck part just remove it and the power is off.

Could also use it for charging up drive battery at least on a trickle charge.

Hi Duncan I did a count of one bundle and it is about 110 strips. I reckon that is enough for 2 lots of hull planking plus the deck. There is a notice on the box cover that you can use either balsa or lime. I shall go for a balsa first layer and finish with the lime.

I planked another model like this and it came out very well (as far as the hull planking goes).

Roy

Hi Roy. There are 112 strips of limewood in the kit and no balsa. There is a note enclosed saying they are updating the materials supplied because of supply issue. Please see the attached photo. I noticed from one of the build blogs that someone had said they wished they had done both layers in limewood - balsa fractures too easily! Cheers Duncan

Hi Duncan how much wood is there in the kit for planking the hull? I have a bundle about the size in your photo of lime wood and another bundle of balsa wood.

I read from the instructions I could use either and another set of instructions that said use the balsa as a first layer and then the lime as the second layer.

Roy

Duncan a good evening
Do you know any retired person who ‘s patient? I don’t😂😂

This will be another interesting model build to follow.
I wish you the best.

Hi Duncan glad you have at last got the kit!
The motors that are suitable are only 25mm diameter or 1 inch in real money. I thought the kit props were not that great but they are probably scale correct. I prefer a more efficient 3 bladed prop.

By the way I found a mixer on Aliexpress that might suit you. Log in and copy and paste.

5Ax2 Brushed ESC Dual Two-way Speed Controller 1:16 RC Tank Tracked 2S 3S Lipo

(6 - 12 volts, but I suggest max of 2 amps per motor. Normal running with prop in water is less than 1 amp at 7,2 volts.

I reckon £20 with p&p etc. The description is very good for the usual Chinese English. You may want to buy suitable made up leads for these connectors they are very cheap and if bought together will probably not increase p&p cost.

ESC's at £1.70 each, they double up in price with tax and postage and a bit of a wait! But 5 for £14 was too much of a bargain to miss and I have been using similar ones before.

A good read of instructions and visualisation of the procedure is a good start. Been doing that for a while.
regards
Roy