Having created the “rotating” monitors I have to deal with the rotation mechanism and since the design requires the central tube to rotate I have a few different options to consider, they include:-
1 solid rod drive
2 Belt driven
3 cord driven
4 modified servo
5 gear driven
Having looked at the rotation of a standard servo which appears to be about 170 degrees, if I want to have something in the order of 300/360 degrees there will have to be some sort of increase in end movement.
Option 1- rod driven although very controllable it’s limited to about 170 degrees otherwise it gets locked at either end of the cycle.

Option 2 - Belt driven needed a couple of pulleys machined up this meant the large pulley was 50 mm dia and the small one was 10mm dia. The drive belt was an “O” ring. This option works very well and could be a possibility.

Option 3 - Cord driven this system is simply a cord running from the servo arms round a 10mm pulley twice (to give some grip) but between the servo arm and cord is a spring to give some tension in the cord, again could be a possibility

Option 4 – a servo modification (addition of resisters) servo this has already been shown by Graham and although an easy option for an electronics engineer a bit more difficult for me, but achievable. However for my configuration it’s not suitable as I can’t drive onto the end face of the rotating tube.

Option 5 – Gear driven would need a pair of gears at a ratio of 10 teeth to 50 teeth and some modification to a gear to fit on the servo. This was the last option to be tried and looks as if it may be the best option. The rotation of 360 may be OK but from a practical point of view I don’t need water spraying over the cockpit or front deck. So I decided to change the gear ratio to 30:10 this gives a rotation of about 280 degrees which I think gives a good spread of spray (see top view of deck).
All the prototypes were built on scraps of ply and with an old servo. Having proved my system; I will now build it into the cabin roof in such a way that the gear ratios can be changed if required.

Having trialled the various options for rotating the monitors I have decided to use the gears option. I am going to mount the servo in the roof. The cabin roofs have bridge pieces which are just about correct to mount some aluminium bars on which will carry the servo
I have reinforced the inside of the roof where the base of the monitors fit as the roof is only made from 1/32” ply, I use an aluminium disc - 25mm dia x 1mm thick . The monitor bases are fastened using three 8BA csk screws and nuts.
(I must say at this point that people may wonder why I use BA nuts, bolts and screws and not metric, it’s because I have a good range of all BA taps and dies)
The aluminium bars are slotted to take the servo and allow for adjustment and again fastened using 8BA hex hd screws and the bars are attached to the roof again using 8BA screws and into the wood! (I have successfully used machine threads into wood of all sizes, this requires the wood area to be treated, I use a RONSEAL product that is for treating rotten wood, it’s a very viscous liquid and soaks into the wood and after an hour or so it goes rock hard the tapped holes can then be clean up with a tap) I can adjust the fit of the gears to give a nice smooth rotation; all that needs to be done now is to design the water system.

I thought I might try the simplest way to produce smoke and just reverse the “vapours” way of using a standard E cig unit. I was given a couple of units which were no longer needed and decide to modify the unit. I machined an aluminium ring which fitted around the air intake at the bottom; the ring has a groove machined internally to allow the air to circulate around the dual intake. A 4mm drilled hole which is drilled into the groove has a 4mm brass tube inserted. The brass tube connects a small pump via a silicon tube which blows air into the device. The battery pack will have to be modified to fit in the boat but this was just to prove the system. It produces more than enough smoke for my crash tender which will just have a scale amount of exhaust smoke, hopefully. I intend piping the smoke through the rear using a custom made water/smoke exit unit which keeps the two components separate, watch this space

I’m not going to give details of painting blow by blow as it’s as bad as watching the paint dry and I’m sure most people are aware of the amount of time the preparations for painting take. So here are a number of pictures of the painting process, sorry miss the red oxide and the deck pictures. The whole boat is now complete with colour and only needs lacquering which will be done after the transfers are applied.

I have laid out all the various components on a building board, not necessarily in the correct orientation/position. The only thing I do know is that water needs to come out of the 4 pipes pointing into the tin.
I have a caravan pump serving as a water scoop (to simulate the water pickup as the boat moves forward) any water going through the system into the tin is piped back into the container under the bench where the pump is.
First thoughts are similar to others in that when the fire monitors are operated the water is drawn back through the exhaust pipes and sucks air. To try and solve this I have put some small solenoid valves in the circuit. But first test show that they restrict the flow too much so a larger valve? Or I think the easiest solution would be to put another entry opening in the hull somewhere near the pump just below the water line on the side mid-ship so the pump can be connected directly and be primed when the boat is at a standstill (anybody see problems with this?) I think the only issue I can see is that when the boats in motion it may force water through the pump – then the monitor result – drip, drip. I think a properly designed inlet, that when in motion the tendency is to draw the air out of the system and not force water in until the boat is at a standstill when the water should just flow in. I have designed another outlet (not shown) for the exit of the cooling water and hopefully the smoke which has the water coming out of the centre 6mm pipe and the smoke exits through the surrounding space between the 6mm pipe and the 8mm surrounding hole.
(Ignore the black pump, top right, it was a first attempt at a water supply, it’s a car washer pump, but not powerful enough)

I have to thank Rob for his trail blazing manufacture of his nets as it made the process of making mine much easier.
I have made mine slightly different because early on in the build I decided to made the cabin roofs as flat and not cluttered as possible to make the painting and rubbing down much easier. So my rails that hold the nets to the roof are made to the same dimensions but are fastened to a sub board which can be attached via pre drilled pins at the very end of the build.
I cut a board to accommodate a 6 x 9 net having a spacing of 23mm squares. I tied the longitudinal ropes (WARP)to the pins and then loaded the home made “needle” which was made from a piece of 3 mm brass rod with a 2.2 hole drilled in one end to glue the rope into and the other end was machined to a point. Having loaded the needle I tied the end to a pin and started to tread the cross treads (WEFT) going through the warp tread until I had crossed all 6 warp threads and tied off on a pin at this point a dab of super glue sets the joint. This continues on 9 weft treads.
The net has now to be fastened to the cabin roof rail and the pole at the bottom of the net. This “pole” is a 3 mm dowel with holes drilled at intervals along its length. The ends are looped through the holes and back through a piece of black shrink sleeve making a secure joint. At the top a similar process of looping around the rail and securing with a piece of black shrink sleeve.finished the 1st scramble net.
“REPEAT” Sorry I forgot to show the board used to tie the warp and weft

As I said before I wanted to separate the smoke from the water so I have made an outlet that will be bolted into the transom that separates the two outlets, whilst appearing to exit through the same hole. First I machined the main body having an outside diameter of 10mm and internally an 8mm diameter bore which carries the smoke out.
Into this 8mm dia there is a 5mm hole drilled at 90 degrees sideways and connects to a second body which is silver soldered to the main body, this has a 6mm entry pipe.
The water is carried out through a 6mm tube which is soft soldered into the main body. Finally an outer ring was machined; it was drilled/tapped 10BA which will allow it to be fastened into the transom. I have yet to try this for real but I see no reason for apprehension!

Much head scratching about the plumbing🤣
I mentioned that I may consider a separate water supply for the monitors as there were so many issues with it all being sourced from the propeller pic-up pipe, I tried with solenoid valves etc etc but there are too many issues about switching, water flow and future breakdowns in the system.
So a separate water supply, however this has its own issues, firstly another hole in the hull mid-ship and a pick-up that wouldn't force water into the hoses when the boat is going forward, and being able to self prime the pump when stationary.
I've come up with this design that fits on the underside of the hull (with some reinforcement) mid ship

I’ve been pulled away from my original plan and spent too much time on smoke machines and spinning water monitors that I’ve neglected to finish the hull. The basic painting of colour is done and now only needs lacquering. Before I started applying the livery I gave the hull a light rub down with 1500 wet & dry to get rid of any pips and to give a sound surface for the final coat of lacquer and give a sound base for the livery.
I took on board a comment that Rob made about the use of the “water slide” transfers supplied, in that the depth of white pigment in the transfers made them look slightly dull, and with the trial I found the transfers were also delicate to say the least. I decided to go ahead with the vinyl alternative because if applied carefully and correctly they will look nice enough.
The process was first to cut out the block of vinyl that carried the FIRE text, followed then by cutting the individual letters out but leaving the waste as a frame for positioning the letters on the hull. So marking out the position of the “E” on the side of the hull and measuring the obligatory 3 TIMES then marking this on a piece of masking tape (at this point I left the job alone for a couple of days, the relevance of which will be seen later), the frame was then taped in position and the letters applied in the appropriate position and lightly pressed down using a finger and pressing from the middle of each letter to make sure all the air was expelled.
At this Point while I had the boat on its side I started to apply the water line starting at the bow and working backwards, I managed to apply it over the chine without any problems apart from the tape not sticking on such tight corners, however persistence paid off and pressing the line repeatedly back in position the line seems to have stuck fast. I managed to work the line around the hull in one piece finishing back at the bow.
So now to remove the frame, “Oh dear” or words to that effect, before the final pressing home of the vinyl I realised to my horror that the word FIRE was too far forward , I had placed the frame with the letter line on the wrong side of the “E”. Note don’t leave a job half way through.
I decided to remove the letters which were unusable and contact Mike Cummings to see if he could supply another set. Unfortunately he hadn’t any stock, and was waiting for new ones to be made, so an alternative was sought, I went to my local model shop and purchased some very lightweight vinyl covering called “ORATRIM white. On measuring the two vinyl’s, the supplied material was 0.0023” thou thick and the new material was only 0.0001” thou which would be better on the hull surface. I cut a set of letters and went through the same application process as before (right side of the line) and on closer inspection I found the new material was a better, brighter white and felt better on the hull. Another plus was the fact that the original vinyl was printed on so in fact wasn’t solid white vinyl and as such was very delicate when pressing down and liable to scratching the white off. The new material was solid vinyl and as such is much more durable and I’m very pleased with the results.

Now this although interesting is quite a challenge for me which I’m really looking forward to as I’m a mechanical engineer and electrical /electronic is another skill to be mastered (to a degree) however at this point it’s all a bit smoke and mirrors, however here goes. Fortunately Rob has laid a well-defined path that I intend to follow with some minor differences due to different equipment. I first made a start on the control system for the battery charging and power supply to the ESC / motor, this was to be a copy of Rob’s design which seemed to be superbly fit for purpose. I first made the support platform from some 6mm black Perspex and fitted all the components onto it. Then using the 12 swg silicon wire I proceeded to cut, form, tin, solder, etc. all the joints. At this point I asked myself how many times did Rob forget to put a piece of heat shrink in the appropriate place before soldering the joint, (I lost count) then finally I placed a few tie wraps in place to neaten up the whole assembly. I have made a bracket to hold both the amp meter and the receiver in place. The receiver I have mounted at 45 degrees /horizontally so that the plugs are easily placed in position.
(next a bit of Vero Board)