The new LiPo batteries are not supplied with any type of connector, so that the user can supply and fit whatever they prefer to use. In my case it was XT60 for all the battery connections but for this refurb I chose to upgrade them all to XT90 to allow for higher discharge rates.
Fortunately I already had sufficient XT90 connector sets in my ‘electrical bits box’ and I soldered these onto the new LiPo batteries, using extreme care to avoid shorts and heat shrink sleeve to insulate the connections.

As the old NiMh batteries were arranged in a series connection I had to modify the cable loom for the single battery connection and re-terminate the fly lead to the battery with an XT90 connector.
I have left the in-board charging facility unchanged as that would require a quite unnecessary change to the entire wiring loom and switch panel. I will be charging the new LiPo batteries, in a fireproof charging 'pouch', on the workbench for safety.

Because the receiver will now be powered from the BEC in the speed controller I have put the (red) 5v supply line of the speed controller back into its 3 pin connector so that the receiver is powered from the speed controller. Whilst I remembered, I dug out the programming card for the controller to set the speed controller for LiPo operation and also set the battery cut-off voltage accordingly.

The receiver was then fixed to the side of the compartment with some cable ties and all of the servo wires tidied up with cable clips, the two receiver aerials were also re-fixed in the recommended 90 degree polarisation and also secured with some clips.

The small ‘platform’ that I had the old receiver battery mounted on is an ideal place for a battery voltage alarm which is a very useful thing to have with a LiPo battery system, the audible warning is very loud and can be heard quite well even when the boat is running at speed and a vital prompt to bring the boat in for a battery swap.

With all of the wiring in place I was able to test the system for full operation and it all worked perfectly. Previously I had to remember to switch on the receiver battery supply before turning on the main power switch, now it is all powered up by the main switch alone.

The motor compartment in the boat is quite large and thus a reasonable volume of air surrounds the motor and despite never having any motor overheating issues previously I did decide to add a fan onto the end of the motor shaft to introduce a bit of air circulation.

This is something that I did on my VMW Thames River Police Launch where the motor is enclosed in quite a small box and benefited from the forced ventilation. It’s not that the Crash Tender really needs it, but more that I have another small computer fan of the right size and that it is so easy to do!

Disassembling the fan is quite brutal but necessary to extract the fan blade in one piece. A hole was then made through the fan at dead centre to the exact diameter of the spigot at the end of the motor using a reamer. The Turnigy Aerodrive motor comes supplied with some extra metal parts for attaching an aero propeller when the motor is used in an aircraft.

The piece is easily re-purposed by cutting off the threaded stud and grinding/sanding the face to a flat and smooth finish, and then it's fitted over the spigot on the end of the motor and secured with the three cap screws which are also supplied with the motor.

I operation the fan is either pushing or pulling air through the motor and stator depending on the direction of rotation, and in either event it is stirring the air in the motor compartment.

This mod seems to add no extra load on the motor, no additional bearing strain, no extra noise and if you’ve got the bits, no cost!

Some while ago I was asked by Vintage Model Works to make new patterns for the fire monitors which are quite characteristic to the RAF Crash Rescue Tender. The current type supplied with the VMW kits are based on a very old pattern from the early days of the model when it was produced by AeroKits many years ago.

I took this as a great honour to be asked and I set about finding as many photographic references, original drawing and early film of the boats in action.

Of particular use was a video from film taken by Pathé, a newsreel company, when the boats were demonstrated to the public, and one sequence showed the fire monitors in action and some very usable detail of the construction and scale.

Having gathered as much detail as I could find I made some scale drawings of the monitors as I perceived them and worked out, as best as possible, the correct scale for the 46” model.

As I don’t have any metal turning experience or equipment I decided that the best material to use for the new patterns was plastic, particularly as some of the parts would need to be heat formed.

I made up a small wood former around which I could bend heated Plasticard rod around to form the distinctive curved shape of the top of the monitor.
This took multiple attempts until I made a satisfactory shape which will still need some filing and shaping to refine it.

With the hardest part out of the way the remainder of the pattern was relatively easy to make by ‘turning’ the rest of the parts for the body and the base in an electric drill chuck against some files and abrasives.
Small details were easy to add such as the reinforcing fillets between the circular flanges and the main pillar and also bolt heads which were made from short sections of hexagonal plastic rod. I added some blocks to the curved part to form the mounting base of the operating handles.

The operating handles themselves were made from some 'D' profile brass rod and they attach to the body of the fire monitor with very fine brass 1.5mm screws.

Once I was happy with the final result I supplied the pattern to VMW for approval.

Sometime later I was sent some samples of the white metal castings to evaluate and to my delight they had turned out quite well with a minimal amount of flashing to file away.
Remarkably they had even made white metal casting of the screws however I don't think they will be strong enough to be used to fix the handles to the monitors.

Next part….assembling and finishing the new monitors.

My first task is to clean up the white metal castings to remove any casting marks and blemishes and to key the surface for a good paint finish.
I have decided that the best way to assemble the monitors is to drill a 3.2mm central hole through the base part to accept a threaded rod which will then hold the top piece firmly.

It is not possible to drill white metal as a drill bit in an electric or hand drill will very soon seize and snap, but the trick is to put a drill bit in a hand chuck and bore the hole a few turns at a time, withdrawing the bit to clear the swarf produced and then continuing.
This is quite laborious work but it is the only way to bore a hole through white metal to any depth.

I did fully drill through the base and to my relief the exit hole was pretty much centre of the casting and I was then able to put the upper casting in place and drill a shallow hole in the top part which was then tapped with a 3mm thread, again this tap had to be done a few turns at a time withdrawing the tap frequently to remove the swarf.

I could then insert a 3mm threaded rod through the castings to pull the two parts together, with a nut on the bottom of the base, in a recessed hole, both with some Loctite threadlock to keep them tight.

To add some extra detail to the monitors I used a couple of steel washers and a plastic spacer between the top and bottom parts to simulate some flanges that are on the real thing.
The white metal casting of the operating handles is a little bit fragile but they will withstand a single bending to introduce the crank that raises the height of the handles for the operator.
I had made the handles for the pattern in brass for strength so I’ll have to see how they fair in the much softer white metal.

The handles are attached to the side bosses of the top hose part using some 1.2mm brass screws, again I very carefully tapped the holes that I made through the casting to get a secure fixing for the handles. The excess brass screw was cut back and the screws re-fixed with a dab of Loctite to ensure they stayed tight.

The new fire monitor kit is actually supplied with four tiny white metal screws for attaching the handles but in my view they are unsuitable to provide any kind of firm fixing and hence my use of proper brass screws as used in my original pattern.
Another small detail on the monitor base is an operating lever that presumably is foot operated to allow the monitor to be unlocked from a centred position and allow the monitor to be rotated to the desired direction, that’s just a guess as I really don’t know the true purpose of that lever!

I made this lever from a short length of brass rod and finished with a small round brass bead on the end. This piece was bent to the correct shape and then epoxied into a hole drilled into the underside if the base.

A side-by-side comparison of the old and new monitors was satisfying to see as the new pattern looks so much more true to the real ones.
With the monitors fully assembled I cleaned them thoroughly with some panel wipe to remove any grease or contaminants and then gave them a light coat of primer.
I had some etch primer to hand so I used that although I don’t think it’s particularly effective on white metal.

The final coats of red acrylic were applied and then some black to simulate the hand grips and finally some ‘bronze’ acrylic for the nozzle at the end of the hose.

When fitted to the boat the monitors look so much more realistic, I hope you would agree?

Vintage Model Works are also introducing some other new fitting for their 46” RAF Crash Rescue Tender to replace older designs and I’ll post some pictures of them in another update.

It’s been a while since I posted my last update of the new fire monitors but for those of you that are interested Vintage Model Works have introduced an extended range of fittings for their 46” Crash Tender including the new monitors that I modelled for them.

The new fire monitors that they asked me to provide patterns for are now available for just £14 plus P+P for the pair.

There’s also a very comprehensive set of parts for the salvage hoses for £23.50 plus PP and also a completely new tow bar kit that that has been accurately modelled at a cost of just £15.50 plus PP

Sadly, I can’t claim to have produced the patterns for the hoses or the tow bar, they are the work of a professional model maker and far better that anything I could make!

I might add that I don’t have any commercial connection to VWM and I produced the new fire monitor patterns purely for the prestige of making a better job than those that were made so many years ago.

All of these items can be seen on the VMW website on the accessories page: https://www.vintagemodelworks.co.uk/?page_id=39