Mersey Class Lifeboat 1/12th Scale

Started by Gregg

92 updates 16 likes 85 comments
Gregg #42 of 93

rudders

The twin rudders used on the Mersey class have a flat plate added to the bottom of the rudder paddle, htis acts as both a trim guide but also as a protective skid when beach recovered. I made up the flat plates from some brass strip, cut to length and width, rounded the ends off and soldered to the rudder paddles.

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Gregg #43 of 93

motor fitting

Now that the motor mounts have dried fully, its time to slide the twin motors in. I am using a pair of 900 size motors, similar in dimension and technical spec to the graupner ones, but at a more "realistic " price. These came off ebay for A£12 each, genuine graupner units are over A£50, when you can buy them, as they are always out of stock everywhere I try. I am using direct drive and have mounted a propshaft support bearing mount, just aft of the flexI coupling, to reduce shaft flex.
I have also begun to add the deck support framework, all joints being either stepped joints or have had triangular ply braces fitted above and below the joints for added strength. Afterall, this framework will have to take a lot of weight and loading once fully built, so far better to build super strong now, than have to try and reinforce later on and end up destroying the deck covering in attempts of removal for repairs.

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Gregg #44 of 93

deck framework

Ive now added quite a fair portion of the deck framing. Al the wood to wood joins being fixed with a mix of cascamite, mixing it to a thicker paste, rather than being too runny and it dripping off the joints. I found that by brushing this stuff on to all the joints in sequence, then allowed me to give all the joints a second coat on the next pass as by this time, the first coat had started to tack off and stay put on the joins.
You will notice from the pictures , that the motors do sit well forward in the hull. this is to keep the motors as level as possible with the prop shafts, so rather than angle the shafts and the props end up digging in to the water at almost 45 degrees, this setup barely tips the scales at 5 degrees off horizontal, thus giving better thrust output from the props. This also has the knock on effect that the universal joints do less work too, so less prone to wear out or at worst........fail!

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Gregg #45 of 93

engine exhausts

I decided to make my own exhaust pipes up, as after seeing the white metal ones sent by Metcalf moulding and looking at the resin ones available from Mac's mouldings, they were not to my own liking. So piece of plastruct tube, flat plasticard disc for the end flap and a couple of sheet cut hinge brackets, its "as good as". The outer flange discs were again flat sheet, with simulated hex bolt heads glued on.
The holes were drilled through the stern to allow the plastruct tubes to pass through, then the end of the tubes inside the hull were "capped" . I will be adding a water pumped supply to these pipes a little later on, to simulate the engine cooling water.... But these pies need to go in before I complete the rudder assemblies, as it makes access much easier to get to these pipes.

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Gregg #46 of 93

Rudders

Now that the exhausts are in and bonded dry, I can now install the twin rudders. the main pivot tubes were bonded in through a wooden support block, bonded on top of the prop tunnels, ensuring the holes are drilled perpendicular to the rudder points. this can be double checked by passing a rudder through the pivot tube, before you glue the pivot tube, in to the wooden block, then it just needs a little filing to the hole to ensure it sits vertically. Then the pivot tube can be bonded in. the water pipes for the exhausts were also fitted, after bonding in a small car washer pipe angled end piece in to the tops of the exhaust outlet pipes [inside the hull]. this pipe will connect up to a water pump in a later update.
1 comment
  1. Dave M
    Vice Admiral
    HI Gregg
    Neat idea for the exhausts. 😀 I have seen this effect on other model lifeboats and it looks very realistic.
    Your rudder horns have given me problems in similar installations. Will you be able to get at them with the deck installed. I used to spend much time trying to adjust mine after knocking one or other of the rudders out of alignment.
    I will have a similar problem with my Arun but access is quite good. I think I put a flat on each rudder shaft to ensure correct alignment. 😉 OK provided you have silver soldered your rudders!

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Gregg #47 of 93

rudder links

to make things as easy as possible, I added 2 blocks of wood to the tops of the prop tunnels [inside] and placed a ply "plate" on the top. I cut a suitable hole in this ply plate, to take the rudder servo and screwed the servo down. I then simply ran a seperate link from either side of the servo horn to each rudder link arm, so one "pushes" and the other "pulls", which still gives you the assurance of rudder control off one rudder if one of the links or rudders "fails".
For those of you worried abotu access to the rudders, please rememebr the rudders sit "inside" the tunnels and dont even have the rudder "tips" showing under the boat, so unless someone deliberately knocks the rudders, the risk of them going out of alignment is remote. BUT to retain access, I have cut the rear deck and made an access plate for the rudders, it also gives me access to the water pump too, but I'm "jumping" build posts here [ha ha]. 🤐
So you wil notice at present the water pipes are directly connected to the pickup, which has been installed on the inner edge of one of the tunnels, again for reduction of damage if placed on the underside of the hull, but at least it still allows me to "water test" the hull in the "domestic test tank" 😯 when ness !

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Gregg #48 of 93

electrical control panel

One last main item to install before finally getting to add on the main deck, is the flat panel which will hold all the main electrical items. This has been mounted on a couple of "side rails", which were bonded to the hull sides, just over the height of the drive motors. the control panel is then rested on the rails and held down by 2 screws on either side, which are accessible from above, when the deck is in place, so IF I need to get at the motors for any reason, I still can do so without conducting open heart surgery!
The control panel will hold the drive controller/s, power fuses, battery connectors and sound system.
The sound system speaker will be mounted to a wedge shapes panel, which sits vertically and directly forward of this control panel.
6 comments
  1. Dave M
    Vice Admiral
    HI Gregg
    Glad to hear it works OK. I did not mean to suggest it would not work or was untested.
    However as a general rule you should keep all dirty wiring (power and motor leads) and components well away from any signal or control wires.
    Many people reading your post may not have your knowledge or exactly the same set up.
    Just noticed you fit your motor suppressors to the motor power wires. To be effective they need to be soldered to the motor connectors and case.
  2. Gregg
    Sub-Lieutenant
    I fit 3 suppressors Dave, 1 across the motor terminals and then 1 each from the terminal to the motor case. it was what I was taught er, "many" yeras ago as an electrical apprentice.
    think its was "second edition" when I did mine [ha ha], whats it on now? 25th? Ive lost count

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Gregg #49 of 93

Main deck.

Now to put a few onlookers minds at rest! Please appreciate that only being able to put 4 pictures per build update is never really easy to explain fully a certain part of a build, not unless you just use general overall views of the boat that is. So doing it "bit by bit" makes things a little long winded on occaision.
Right, the main deck, cut from a sheet of 1.5mm ply. Well it does not have to carry much weight, all the deck beams do that work, but you do need something flexible enough to follow the contours of the deck, especially at the stern, which does have more of a curve that towards the bows. The deck overlaps the hull sides by 5mm, which then acts as a top locator for the rubber buffer/fender that this class carries. You will also notice that I retain part of the internal cutout piece, this then covers the electrical goodies and acts as a secondary water splash shield to protect them. it also acts as an "antI finger poking" shield if the superstructure is left off for display purposes too. Well, how many people do you know that cant look without touching too ! [ha ha].
you can also now see the stern cutout piece in the deck, for rudder access. This nicely locates just behind the flying bridge area, so not too obtrusive once it is secured down with 2 countersunk screws and all thr stern gear is attached.
This deck is merely the under layer, there is another layer to go on next.......... no, not wooden ! ... but for a reason !
4 comments
  1. ivorrees
    Recruit
    Gregg, About to start on a Mersey. Waiting for the mouldings to arrive! What did you use for the 'rubber buffer/fender' where deck meets hull?
    Great blog!! Ivor
  2. Gregg
    Sub-Lieutenant
    I searched ebay and found a supplier who could do some nice hollow "D" shaped rubber tube, complete with adhesive tape on the flat side and to date it has not come adrift.

    PLEASE remember, if you want the boat to get anywhere near to its scale cruising speed and "semI plane", KEEP THE BUILD LIGHT !
    use plasticard to complete the missing upper cabin, not ply even, it weighs too much and watch out on fittings, the available white metal handrail stanchions are too soft and snap too easily, make your own from brass tube.

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Gregg #50 of 93

Main deck pt2

Now the wooden deck has had time to dry fully to the underframes. its time now to apply the top coat. for purse ease of attaching upper deck components I decided to use a sheet of plasticard. this then allows me to simply use plasticweld to attach anything else to it. So the capstan,anchor mounts, and more Importantly, the "toe boards" are plasticwelded in place, giving a strong bond. I did not want to use wood for the deck and it makes it difficult to attach anything else to it, not unless you use screws as well, which then adds to the weight and complexity of the build. the toe boards, if I made from ply, would be quite fragile, especially if knocked during transit and they would split, so by using plasticard, they will allow a bit of flexability, they are lightweight and easy to attach and shape/drill.

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Gregg #51 of 93

Engine vent grilles

Whilst the deck is setting nicely in place, I'll move back up to the superstructure for a while again. I did purchses some resin cast engine grilles, but due to their real lack of details, plus had swind down covers attached which also had louvers in, which as you can appreciate is incorrect, I decided to make my own.
The basis frame was measured out from the plans and a frame os plastic strip was cut and glued together. I then cut a series of strips to make the vertical grill louvres from some more "thinner" plastic strip from the plastruct range, these were cut carefully, so they were a "pinch fit" and a small dab of liquid glue applied to the top and bottom edges to bond them in. Once in place, its easy to "realign" the louvres with a pin or finr knife blade, to make sure they all point at an even angle.

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