A cold, frosty morning with little wind provided ideal conditions for the maiden voyage.

As soon as the boat was in the water, Finley took control. He remembered the control functions from the 'bathtub' test and had little difficulty in sailing the model. It is fast and responsive.

Grandad was more stressed than he was, trying to ensure that there were no collisions with the other boats on the lake, or with the ducks!!

All in all, a nice kit to build with only a few small issues. A convenient size, easy to transport and store. It sails well and looks good on the water.

What's next I wonder?

A ship's wheel was marked out on plastic sheeting using a compass. The pieces were glued together and then carved to shape. The completed wheel we trial fitted before painting.

Finley found a 'Skipper' among his large box of Lego. The scale doesn't look too bad.

Lifebelts were also made from plastic sheet, turned on the lathe, painted and with ropes added. Handrails made from brass wire and small woodscrews were added to the main cabin roof.

Finally a quick test float in the 'domestic test tank' in preparation for the maiden voyage on the lake.

As Michael noticed in the last post, there is a blue Police light on the cabin roof. This is one half of the 'blues and twos' installation on the boat.

The light was bought on-line and simply plugs into a spare channel on the Rx. Using the corresponding switch channel on the Tx allows four different flashing patterns to be selected in sequence.

The two tone horn is provided by a small waterproof speaker mounted on the underside of the main cabin roof. This is driven by a two tone oscillator (yes, another PIC!) plugged into another Rx channel. To disguise the hole for the speaker in the cabin roof, a lifeboat is mounted on spacers above the hole. The lifeboat was bought as a 3D printed item and painted appropriately.

With all the bits and pieces fitted, time for a short video:

The navigation lights are simply red and green leds fitted through holes in the cabin roof. The leds are wired in series and connected to one port of a two port RCswitch.

A simple searchlight was built from bits of plastic tube and fitted with a 5mm white led. This is connected to the second port of the two port RCswitch.

The RCswitch is homemade based on a PIC microchip programmed to allow control of the two outputs from the Ch4 joystick on the Tx. From centre position, pushing the joystick to one side turns on the nav lights. Pushing it to the other side turns on the spotlight. Repeating these movements turns off the lights. The RCswitch, protected with green heatshrink, is attached to the underside of the cabin roof with velcro.

I want to add as many 'bells and whistles' to the boat as I reasonably can to give my grandson plenty of controls to operate. That should make it more interesting (and challenging) for him to operate.

First up is the radar. Martin recently posted in his blog an excellent write-up of how to build and motorise a radar:

blogs/96788#100486

wiki/101690

Before fitting the motor, Finley added vinyl decals to each side of the hull. I'd sourced these from ebay and it was a simple task to position them and rub them down onto the hull before peeling off the protective film. The hull will be lacquered later to seal and protect the decals.

The motor was screwed into position on the previously installed mounting block. Small fingers are definitely an advantage when placing the screws into position 😉. The propshaft was coupled to the motor with a metal flexible joint. Connecting the ESC, battery and a servo tester allowed for a quick test of the installation. The noise was terrible !🙉 Despite the care taken earlier in the build to align the motor and propshaft, something was not right. Loosening the motor mount screws and wiggling the motor mount resulted in better alignment and slightly less noise 🤔.

Moving on to the rudder, the 9g servo was fitted to the mounting plate and a wire link connected between the rudder horn and servo. Again small fingers made this easier. A quick test showed the rudder works smoothly - and without any significant noise! 👍

Once Finley had gone home I decided to revisit the motor coupling issue. JBkiwi uses rubber tubing to link his motors to propshafts so a length of 3mm bore silicone vacuum hose was ordered to replace the metal coupling. This turned out to be a bargain. A 500mm length of silicone tube, 3mm bore with 2mm thick walls sent by First Class post for a total cost of 99p. There is enough tube for at least 10 couplings for less than 10p each 👍👍

Fitting the new coupling was straightforward. The motor shaft and propshaft are both 4mm dia so the silicone is a tight fit. I did have to shorten the propshaft tube by 5mm to give enough exposed shaft to slide the coupling onto as well as having enough room to fit a brass collar between the coupling and the propshaft. This collar is held in place with a grubscrew and ensures that the propshaft cannot slide out of the tube should there be any slippage of the coupling on the shaft.

I'm pleased to be able to report that there is now an acceptable level of noise when the motor is running. All of the noise is now the usual high pitched whine from the motor, with no sound from the coupling.😁

With the hull assembly complete, its time to get painting!

The hull was first coated with epoxy resin and fibreglass cloth.

Once set, the rubbing strips were shaped and fitted to the gunwales. A former to bend these strips was cut from some scrap MDF using the top deck outline left in the laser cut ply as a template. The rubbing strips were soaked in hot water, clamped in the former until dry and then glued in place.

Grey primer and knifing putty were used to prepare the hull for the finish coats of paint. The deck was been painted with a textured paint to give a non-slip appearance. The hull sides are dark blue (left over from the Gaff Cutter). Below the waterline is red primer.
A white pinstripe was added to separate the two colours.

The kit comes with 3D printed window frames. These were primed with an etch primer and then painted white. Windows are glazed with clear plastic sheet which was also supplied with the kit. The superstructure was painted grey and the completed windows glued in place.

Finally a few decals complete the overall effect.

Finley has been back at school so he hasn't seen the recent progress but it is half term this week. He's going to be a bit surprised when he sees it!

Now it's time to start adding the electronics..

The hull sides and bottom are skinned with 1mm ply. This is supplied laser cut to size.

I held the first side in place while Finley applied the superglue. I'd bought some superglue from the local pound store which came with a long flexible nozzle which was ideal as it allowed me to keep my fingers away from the liberal application of glue by Finley 😉. I'm amused by the wording on the package and haven't yet worked out how to 'reuse' the glue that didn't go in the right place! 😂🤣

Finley's younger sister decided she would like to be involved 🙄 Unfortunately her idea of helping was to grab anything she could in the workshop that was within reach, so we had to cut the session short.

I used my trusty block plane to trim the side to size, and then fitted the other side. Before fitting the bottom panels holes were drilled in the framework so that it would be possible to seal all the internal ply once the hull was complete. The bottom sheets were glued in place and held with masking tape while the glue set. These sheets were barely long enough or wide enough at the transom. A few more mm in length and width would have helped. The gaps were filled with epoxy and smoothed to shape.

I also made a simple stand for the completed model which Finley helped to paint with 'quick drying woodstain'. This is ideal for this application as it is water based and washes off little sticky fingers quite easily 👍

Another part of the RC installation best completed before the skins are applied to the hull is the rudder and associated servo.

A simple rudder was first made from some thin brass sheet and a length of 3mm brass rod. I think it may be a bit on the large size, but better that than too small. I can always trim it down if it proves to be overly effective.

There is no information with the kit about locating the rudder. A laser etched marking for the recommended position would be helpful for a novice building the kit. I chose a position to give plenty of clearance behind the prop on the basis that 'if it looks right, it probably is'... time will tell.

A brass tube was installed through the bottom of the hull. A servo mount was cut from spare ply that came with the kit. The top of the rudder tube passes through this ply panel and is epoxied in place to provide plenty of support.

Now that the motor and rudder installation are complete, it is time to fit the side and bottom skins. I just need to wait for Finley's return....

Before Finley returns to continue with the construction. I need to install and align the motor and propshaft.

The instruction booklet suggests fitting a 1500kV brushless motor which surprised me as I was expecting it to call for a brushed motor, but I thought 'why not?' so a suitable motor and ESC were ordered.

First job once the motor arrived was to make a mounting bracket. I found an old domestic radiator mounting bracket in the scrap box. A short length cut from this gave a strong, lightweight right angled bracket. Four holes were drilled and tapped for the motor mount, and another four holes drilled and countersunk for screwing the bracket into the hull.

The motor has a 4mm dia. shaft and I'd already found a 30mm propeller, left over from Crash Tender commissioning, which had an M4 thread. Based on these part dimensions, I decided to use a 4mm propshaft and a 7mm dia. outer tube. With the tube in situ, but not glued, a hardwood wedge was made to match the angle of the tube. To align the motor shaft with the tube, an alignment tool was made. This is simply a length of steel which was turned to be a sliding fit in the propshaft tube, and with a 4mm hole to slip over the motor shaft. With this tool, it was a simple matter to adjust the heights of the wooden wedge to align the motor shaft with the propshaft tube. The wedge was then glued into position.

While the glue was drying, two phosphor bronze bushes were turned for the propshaft. With these fitted, and the alignment tool used to ensure everything was in line, the propshaft tube was epoxied into position.

Finally, the alignment tool was replaced with a universal coupling, and the other end of the shaft was threaded M4 so that the propeller could be attached. A quick check was carried out with the ESC attached and powered up. All seems to be OK so far. 🤞