A radio controlled model sail boat build. Back to my childhood, but with a few more skills.

 At age 6 my father built me a scaled down, M class model at 24 inches long.

My Father lifted the lines from a book called "The Boat Model Book" by G.H Deason, 1950. Father had some old matched lining planks of Kahikatea, a lightweight, blond conifer wood, a New Zealand native species. She was constructed in the "Bread and Butter method". Father was an expert wood worker and seasoned model maker.

He called her Marina. She was painted Zenith blue with a varnished, mahogany deck. The rig was of wood

and calico, with the sails sewed skillfully by my mother. Fittings were of brass with waxed twine rigging.

That model still resides at our family home, 60 years later. I was obsessed with it as a young boy and I took every opportunity to make the 10 minute walk to our local beach at Waiake, on Auckland's North Shore, to sail her, at the end of my fishing line.

I was growing my adult teeth at the time. Now, at age 66, I'm beginning to loose those teeth, and now I'm back to playing with model boats as well!

This is my latest RC model.

named Harmony, she was originally an unfinished 1/32 scale display model of Shamrock 111 by William Fyfe 111, which I bought from a local thrift store, 3 years ago. She's gone through some changes since I've owned her.

Here's the story of her build so far.

This is the glass hull as I originally bought her in 2020.

1/32 scale model of Shamrock 111.

1/32 scale model of Shamrock 111.

The hull and decks are fibreglass with lead poured into the open keel cavity.

She's 48 inches in length, (1240 mm)

1/32 scale model of Shamrock 111.

After some extensive internet searching I found the lines of the hull that my model was based on.

       Half model of Shamrock 111 at                Greenwich Maritime Museum.

Shamrock 111 in 1903. Belfast Shipyard dry dock.

1903 America's Cup challenger for Sir Thomas Lipton.

She was built from welded, chrome steel plates. Exceptional technology for the period.

Here I have sectioned the old fixed rudder from the hull, which was defined by a clear part line. Once removed, I fitted a carbon rod shaft and then extended its surface area with 0.5mm copper sheet, tabbed and glued, to fit tightly to the trailing edge. The next step was to fair the old rudder into the new form, using epoxy resin and loose chopped strand glass rovings. One cured, it was sanded and filled with polyester filler, then primed and painted.

The trailing edge of the keel needed sealing and shaping, to accept the shaft and a brass tube, fitted to carry the shaft through to deck level.

With the additional 500 grams of lead added to the keel, and the extra rudder area, Harmony was ready for the water again.

My custom built sheet winch utilizing Connex, plastic sprocket gears to give a 1.5:1 ratio reduction to the main sail and jib control lever.

These fittings were fabricated from  13mm copper plumbing fittings. The mast step is a copper 2 cent piece, soldered to the mast base.

A stainless steel fishing swivel serves for the jib boom swivel.

My bowsies are fabricated from 3 brass ball ends, removed from old guitar strings. These I soldered together in a gang of 3.

Here you can see the rudder quadrant which I fabricated from circuit board tuffnell, with a locking bolt, to secure it to the shaft. The control cables are attached to either side of the quadrant, then pass through 2 small slots in the deck. They pass over two brass rollers, then run aft, under the dec, to the servo horns.

The addition of 500 grams of lead, cast into a plaster mold taken from the original keel made her less tender.

The new, additional lead, faired and painted.

Under sail, she sat slightly lower in the water, right on her marks. She tended to drag her gunwale, increasing the risk of getting water into her access hatch. Full scale J class yachts are infamous for this trait as well. Not desirable in a small sailing model.

I decided to add 13 mm more freeboard to assist with her performance and to minimize water coming onto her deck.

This is the mahogany nose block which was notched to receive the mahogany gunwale stringers.

The mahogany transom block received the mahogany gunwale strakes.

Deck beams glued in. I bolted the cockpit deck beams to the old glass deck to provide a bit more support to this weakened area around the hatch.

I routed out all the remaining fibreglass deck, leaving the deck beams ready for the new deck skin, which comprises 0.8mm birch ply, sealed and glued with epoxy resin.

Overall the hull is 20mm longer than she was (now 1260mm in length) as a result of the extra 13mm of free board.

Penetrating epoxy applied, the deck is ready for a final sand and clear coat.

  

 0.8mm birch ply with sycamore and mahogany planks, glued in place, one by one, a very slow process.

Guide coats of left over colours from other projects helped me to fair the hull before final coating.

It was my wife Julie's idea to go with this colour sceme, a combination we both love.

I belive Harmony has lost nothing of her original grace by adding the extra freeboard and her varnished wooden deck makes her look very smart and sophisticated.

I sewed Harmony's sails myself from 4 oz, dacron sail cloth. The cloth is a trifle heavy, so a new suit of sails will follow soon.

Now Harmony is much stiffer in a breeze and sails more upright with less water coming aboard.

I added a total of 1 kg extra weight, 300 grams of which was lead ballast placed into the hull in the keel cavity.

The removal of the old deck lightened the hull by 200 grams so there was a net increase in weight of 800 grams.

Harmony now weighs in just short of 7 kg with rc gear, battery and rig.

She's less tender than she was and I have better overall control.

Her steering has improved through a re-design of the steering servo tackle, and increasing the room around the trailing edge of her keel.

Most importantly, I replaced my transmitter and receiver with new equipment.

They are a 6 channel transmitter and receiver by KDS. It is set up in Mode 2,

only needing 2 channels, one for sheet control and the other for steering with end point adjustment control to limit servo travel on both of those channels.

The Transmitter is supplied with 12 volts DC from a lead acid battery which I carry in a belt pouch bag with a power lead to the TX battery connector.