"Re: Constructing 'The Box'
11 hours ago by Skydive130 ( Warrant Officer)

"I have just taken delivery of this kit, and the joy opening the box and getting that wafting smell of fresh wood, nothing like it!

Having check the excellent quality laser cut wood against the parts list, it seems that the basic box built first is now supplied as 6mm and 5mm ply instead of balsa. Can I presume this is a change to the test kit? I am not worried about the extra weight, less ballast at the end.

My only other issue now is trying to source the HobbyKing SK3 840kv motor you have used in your beautiful model as it’s currently out of stock in the Uk and EU, living only 3 miles from HobbyKing UK means I can order and sometimes pick up same day. Does anyone else have an suitable alternative recommendations for the motor if I cannot source an SK3. I could order from HobbyKing in HK as showing in stock, but the postage is high?"

Hi Skydive130
I have moved this to the end of my blog so that others can see it easily.

Yes, I understand that the box is now all ply construction, I doubt if the added weight will be any problem at all.
Re: the HK motor, speak to Mike at VMW I'm sure that he or his colleague Alan can suggest a suitable alternative.
Good luck with the build and ......Please Do A Build Blog 😁👍.
Robbob.

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With the annual club exhibition coming up I made a display stand for the boat, the construction is just the same as the one I made for my RAF Crash Tender.

I had to make some card templates of the hull at the bow and stern to get the end panels the right shape and transferred these to a pair of drawings allowing for a strip of 10mm thick neoprene foam to cushion the hull.

The end panels were cut from 10mm ply and the side rails are 8mm softwood set into the end panels and just glued and pinned.

After a thorough rub down I gave the stand three coats of a Mahogany stain before fitting the self- adhesive neoprene strips.

I had a pair of engraved brass plaques made up with a description of the boat, one for each side and Mike Cummings at Vintage Model Works very kindly supplied some VMW stickers to go on each side 👍 and there are some Model-Boats.com stickers on there too 👍😀.

I’m just contemplating the construction of a transport and storage case for this model and a recent thread on this site has been very helpful in highlighting some strong but lightweight plastics that may do the job.

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I decided that an instrument panel would enhance the appearance of the ‘Steering Wheel’ power switch so I made up a panel to go around the switch onto which I could put some dials and a throttle control.

In my previous blog update I discounted using the very nice but pricey BECC transfers and looked for an alternative, Doug (RNinMunich) kindly sent me a .pdf of some instruments but the resolution was very poor when printed out. So after a bit of Googling I found a picture of some real commercially made instruments that was quite high resolution, and importantly, printed very nicely even when scaled down to the sizes I needed. I used a premium glossy photo paper in my Canon Pixma printer for this.

The panel was made from some 2.0mm ply from the scrap box with the edges bevelled for neatness and after two coats of Teak stain they were ready to have the dials applied.

The dials were cut out from the printed sheet as best as possible with a new scalpel blade, not easy I might add, as they are so small that you can’t really make a continuous circular cut so it was a case of nibbling round the edges until it was an acceptable shape. That was a test for my old eyes 🤓 I can tell you.
The edges of the dials were blackened with a black ‘Sharpie’ pen before sticking down onto the panel with a light smear of canopy glue.

The throttle control is just an offcut of Obeche carved and shaped and with a short piece of styrene tube and a pin head for the lever, painted in gunmetal grey it doesn’t look too bad. I used a small white ball headed pin in the final assembly.
The instrument panel was given two coats of satin lacquer to protect the dials before the throttle control was stuck down and then the whole piece glued down onto the battery cover, and I also painted the aluminium switch panel black so it was less conspicuous through the slot.

I had arranged the height of the wheel so that the battery cover can only be removed with the switch on the off position as a safety consideration. Also there’s room inside the battery box for a low voltage alarm attached to the battery balance connector too.

Viewed through the cabin window the instrument panel looks quite acceptable and it all helps to disguise the purpose of the steering wheel and the switch can be accessed easily through the sliding cabin window without removing the cabin.

Quite pleased with that 😁

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The switch and battery box is a sub-assembly that can be easily removed for repair or modification, and the ‘steering wheel’ power switch works really well but it all needs to be concealed in an enclosure that’s in keeping with the rest of the boat.

Firstly I built up a framework on the walls and floor around the battery box to support an enclosure, this was designed with a sloping top panel to make it look more like a control and instrument panel than just a box. The obeche strips were angled and bevelled and just superglued in place.

The enclosure was then built up on this framework to get the shape and angles right and all the internal edges reinforced with obeche strip with some bracing pieces at each end to add rigidity.

A slot was cut into the top panel to allow for the throw of the power switch and the edges of this were also reinforced with some more obeche strip.

Some external framing detail was added and also a handle to assist with removal as the 4mm diameter neodymium magnets that were set into the framing hold it very firmly in place. I uses a total of 6 pairs of these magnets and I now think that 4 pairs would have been more than sufficient and hence the need for a sturdy handle to get a good grip!

(I did a count up of how many magnets are on this model and in total there are 42 of varying sizes 😲)

Three of coats of Teak stain were applied to all the bare wood to finish it off.

I may add some ‘instrumentation’ detail on the top panel around the steering wheel and possibly a throttle control just as a finishing detail.
BECC do some nice round decals and bezels for this but they’re a bit pricey for just the few that I need so this extra detail might be an unnecessary extravagance!

The last thing to make is a presentable looking display stand for exhibition and display so it’s off to the drawing board to sketch something out ✍🤓.

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I don’t know what it is about successfully applying a white waterline to a hull that gives me so much grief.
I had problems with getting a good result with my Crash Tender and similarly with this model too.
The common denominators are;

1. Me.
2. The hull.
3. Trimline Tape.

On both occasions I’ve used this tape it has refused to adhere properly where it crosses the spray rails and on this occasion it also lifted in lots of places along the hull sides so that when the finishing lacquer was sprayed on it got behind the tape, lifted it more, and looked awful 😞 and this was despite meticulous cleaning and keying of the surface before application.
Without meaning to do an injustice to the product I suspect that it’s just the way I was applying it and perhaps I had greater expectations of the product.
Consequently I had to remove all of the tape and flat down the step in the lacquer coat 😠 and consider another approach, perhaps masking tape and white paint or an alternative tape.
I decided to persist with the ‘tape’ method so I found a seller on eBay that could supply very thin PVC car body ‘coachlining’ tape in any colour or width to order, so I bought 10 metres of 4mm in white for just a couple of quid.
What a difference!😊
This stuff went on beautifully straight, sticks like the proverbial and has stayed firmly in place over all of the contortions of the spray rails and hull.
Furthermore when the hull was re-lacquered with a clear satin finish it behaved impeccably….success at last.😀👍

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The final piece of cabin detail to add was a spray deflector rail.

Making the piece was reasonably easy as it just involved shaping a length of obeche strip into a triangular section and then gently steaming and bending it to as much as a curvature as possible without snapping it.

Because the roof is also a convex shape the strip had to be further shaped while held in a bent form to flatten the centre slightly so that it would sit correctly on the roof over its length.
When I was happy with the shape and fit I stained the piece with two coats of Teak stain.
Fixing the piece down onto the roof was the bit that worried me most as I couldn’t drill any holes for retaining studs as I had done with other roof details for fear of splitting it and so superglueing it directly to the roof was the only way, and I had to get it right first time. 😓

For this part I had to enlist another pair of hands 🙌 to ensure it stuck down properly first time so after choreographing and rehearsing the action a few times I applied a very thin bead of superglue to the part, bent it to the required curvature and placed the ends on the corners of the roof and then rotated the piece down onto the painted surface of the roof at which point the other hands pushed it down firmly in place and held for a minute or more until the bond was complete.

Much to my relief 😊 it was a successful process and I was then able to trim the ends back with a sharp blade and paint the cut ends with a bit of Teak stain😁
The cabin is completed…….finally.😊

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There are a couple of grab handles on the front and rear of the cabin roof that I thought I’d like to add to my model.

Making them from wood seemed rather difficult so I made them from some plasticard rod that I heated and bent over a former to the right size and shape. They were then rubbed down with an abrasive to roughen the surface so that the wood stain that I’ve used elsewhere would stick properly and two coats of Teak stain did the trick.

Superglueing them directly to the cabin would not be a very firm fixing so I drilled some 2.5m holes correctly spaced so that the handles could be pushed into place and I used some canopy glue as a fixing so that any excess glue could be wiped away easily.
When the glue had set I gave the handles a final coat of stain using a very fine brush, a steady hand and an old pair of eyes 🤓.

Just the spray deflector on the roof to fit now.

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A rather nice feature on the NMM model are some brass trims on the rear pillars of the cabin and I found a ‘photo of one of the real boats that clearly shows the trims so I decided to add these to my model too.

The brass sheet I used for this is only 0.3mm thick and can be fairly easily be cut by scoring heavily with a strong knife blade and then snapping. The cut edges show no sign of deformation and are easily smoothed and finished with a file.

The strips are about 6mm wide and each strip was trimmed to fit the upper part of the cabin pillars and the lower curved portion formed by careful bending over a suitably sized former.
They are held in place with a few spots of superglue and after a final cleaning with fine emery paper were brush painted with a couple of coats of clear lacquer.

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I did consider making my own rudder from brass tube, rod and sheet but I realised that a standard commercially available rudder could be easily modified to simulate the rudder type used on the real boat.

I ordered a ‘large’ size standard rudder from ModelBoatBits along with the prop shaft and prop that were needed for the model and then set about modifying the rudder.

As the blade of the rudder is held in a slot in the rudder post by a couple of small 'rivets' it was an easy job to just punch them out and separate the parts. The rudder blade was then rotated 90 degrees and a single new hole drilled through to fix the blade in the new position.
I re-shaped the blade a little to more of a rounded profile before fixing it back onto the shaft with the original rivets. I also used a small piece of brass rod to fill the exposed original rivet hole and all the parts were soft soldered together.

The new rivet was filed down flush with the blade and the whole part burnished and finished with a coat of clear lacquer.

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I wanted to install a main power switch on the model so that the battery could be pre-installed and connected ready for the lake but at the same time the battery needed to be easily replaceable at the lakeside. The problem I faced was where I could fit and conceal a switch for this, and have it easily accessible too.

The answer, I decided, was to disguise the switch as a cabin feature that I intended to include in the model detailing anyway, and the boats steering wheel was the ideal candidate.

I started by sketching out a design that would incorporate a battery box and switch as a complete sub-assembly and with a workable design I began by constructing the battery box from 3mm ply.

The switch mounting was formed from 1.2mm aluminium plate for which I made up a card template to determine the right size and angle of bends required to obtain the ‘slope’ of the top panel. Once formed and drilled the switch plate was fixed to another ply panel on one end of the box and fixed in place with screws.

I found the XT60 connector mounting PCB on the Hobbyking site and it is perfect for my needs so the alloy mounting plate was drilled with clearance holes for the connecting pins and the heat shrink tubing that further insulates the soldered connections, and the PCB is fixed to the plate with a couple of M3 screws and nuts.

The switch is rated at 12v 25A and I disassembled it to remove the operating toggle so that I could remove the taper on the shaft and reduce it to a 4mm diameter to take a brass tube that forms the new steering column.
The plastic steering wheel was picked up from the SHG stand at the Thornbury model show and is a perfect scale for the boat and it’s a perfect fit inside the brass tube too.
The switch contacts were bent to give some clearance for the wiring. A cautionary note with these switches, don’t solder any wires directly to them as the heat from the iron will also melt and deform the plastic case too. This causes the internal contacts to move and lose their firm ‘snap’ contact and potentially compromise the switch rating. I discovered this very quickly but thankfully I had ordered two switches, as they are not expensive, so I had an immediate replacement that was then wired with spade connectors.

The switch assembly was finished with another XT60 connector that mates with the power cable that goes back to the ESC via a 15A blade fuse. The whole switch and battery assembly is fixed to the deck floor with three woodscrews and so the whole assembly is removable for maintenance or modification if required.

When I glazed the cabin I made the port sliding window movable (but with an end retaining stop) so that I could quickly access the ‘Steering Wheel’ switch without having to remove the cabin from the boat. A battery change will involve that but as the whole cabin is retained by six small but very powerful neodymium magnets this is very quick and simple matter anyway.

The whole battery box and switch will later be ‘boxed in’ with a false control panel with a throttle control and dials, and this will also be on magnetic retainers, with the battery section as a separate removable part for an easy battery change.

All of these features I had considered and planned at an early stage and so implementing them was quite straightforward.🤔🤓

Getting closer to completion now, along with the control panel cover I need to re-shape the brass rudder and also fix the waterline tape problem that has really annoyed me!😡 More on that in a later update.😁

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