TEV Wahine 1/35 Build

[Richard H DunnParticipant @richardhdunn]

I couldn't help myself

They are just sitting there right now and not aligned or anything and of course I have not silver soldered the A bracket legs on yet

The Phosphor Bronze bearings have not been pushed home yet either

Edited By Richard Dunn 3 on 04/08/2016 04:09:13

Edited By Richard Dunn 3 on 04/08/2016 04:09:26

[shipwrightParticipant @shipwright]

Richard,

Please make sure you don't knock the shafts as they are vulnerable without the A frames !

I would have felt very nervous whilst cutting off the top half of the hull (assuming that I have understood your posting) – how did you keep the cut level ?

You will need some serious fuse/cutout protection when it comes to the main electrical installation because the large capacity lead acid batteries are capable of delivering many hundreds of amps under short circuit conditions – you don't want every seaman's nightmare a "fire on a ship at sea"

How accessible will the running gear be once the two halves of the hull are reunited and the superstructure installed ?

Well done. This is the most astounding model ship project that I have seen (in terms of size, weight and quality of construction, attention to detail). The 200 kg displacement is impressive. Will you use the equivalent of a boat trolley to launch into the lake ?

Ian

[Richard H DunnParticipant @richardhdunn]

The shafts are safely removed now.

The hull was built to split, the frames were tacked with gussets and the seam between the topsides and planking was not glued, see earlier posts where I talked about this

A few sharp blows of rubber mallet and off she popped.

Access is massive and will post a shot later, but not an issue and yes I will have a trailer made for the 4 kilometer drive to the lake

[Colin BishopModerator @colinbishop34627]

I agree with Shipwright, this is a fascinating build and a masterclass in modelling a very attractive prototype. I am following it with very great interest.

Colin

[BanjomanParticipant @banjoman]

As already stated, this build is so jaw-droppingly impressive that one has to ration one's praise for fear of otherwise completely running out of superlatives, but I will take this opportunity to join the above chorus of praise: what you are doing here, Richard, is indeed masterly!

/Mattias

[Richard H DunnParticipant @richardhdunn]

Shipwright asked about access to the hull and I promised photos to show that

Here is a shot I took on a stool to show you the hatch removed.

I think this worked out well in hindsight, the access to the bow is done as follows, you can see the fan room on the fore deck and the area that is where the scraper is , the scraper is the windless pad, both of those will lift of for access to the thruster and bow rudder gear.

The lid can be seen leaning on the wall behind.

I have to say although this model is 4.7m it does not seem so big now, I may have lost perspective….. Haha.

I hope this answers the question.

Once again thanks for the encouraging words.

[Richard H DunnParticipant @richardhdunn]

Anyone have any advice about Silver Soldering this A Bracket?.

Just wondering if I do one leg if the joint will melt when I do the other, they are 55 degrees apart and on the other side. I have not done a lot of bigger joints like this.

I have also done the grills on the outer sections of the thruster tunnels so they can be installed

This is the outer leg fitted, and I have made locator pins to keep the angle while being Soldered.

The Boss is 23mm in Dia with a wall thickness of 5 mm if you want to know the size of this assembly.

I fitted the leg to the side of the Boss with the Dremel and it's pretty close, probably no more that .3mm gap in places

The palm in the hull fitted to girder, this will be bolted with 3mm bolts.

[Bob Abell 2Participant @bobabell2]

Hello Richard

I don't think you've told us what metal are you using?

It looks like Ali or stainless steel etc?

Assuming it's solderable, both legs really need to be soldered at the same time

Failing that…….Silver solder one leg, for strength, then soft solder the second?

Nice quality build………Well beyond my class of work…………That's why I'm on the quiet side, these days!

Bob

[Richard H DunnParticipant @richardhdunn]

Opps

Its all Brass

[Bob Abell 2Participant @bobabell2]

From my Loco boiler building days, I seem to remember that silver soldering brass was risky, as the melting point is quite low and also, the Zinc content breaks down?

Try it first on a piece of scrap brass?

Bob

[Richard H DunnParticipant @richardhdunn]

A lot of modellers and engineers do it and I have done it for years with no side effect what so ever, the hard solders and flux these days are much better.
I was more asking about the logistics of doing an A bracket in one go or in 2 goes, as It will be hard to get the heat on 2 parts.

I guess I will just try it and if it lets go the other leg, lesson learned……no biggie to make a new part…..well a day per leg by the time I re file the contours…………….madness…

[John W EParticipant @johnwe]

Hi there

I am a bit like Bob, I don't like the comment on such excellent work because it puts my offerings to shame, However, to help you out making your A Frames for your prop shafts, have you thought of making a simple jig similar to the one I constructed when I built HMS York – the type 42 Destroyer and also several other warships.

I have put a little picture on of the jig which I made and the way I get the angles of the legs is to put little packing pieces under the legs to alter the angles.

I hope this gives you some ideas,

John

[Bob Abell 2Participant @bobabell2]

That`s a practical fixture, John

But I would have reduced the heat sink effect though?

Did you achieve a bright cherry red with your setup?

Bob

[John W EParticipant @johnwe]

Hi ya Bob

When the jig was first made I heated the whole lot up on the gas ring to do the silver soldering on the A Frames. Consequently I was banned from the house not only for the fumes, but from marking the top of the hob so in came plan B. Out with dad's old paraffin blow lamp (the old fashioned type) built a small hearth in the garden from firebricks and set about singeing me eyebrows whilst trying to light the blowlamp. Can you remember old 'prickers' for trying to clear the jet out. That was quite successful – I learned that if you place it on a firebrick and heated the whole lot up – it maintained the heat and I could silver solder it with a small butane gas torch as long as I heated the bricks up with the old blowlamp. But, for the smaller models such as HMS York and soforth I tend to soft solder the A Frame- because – to be honest I don't think there is much stress on the A Frames if you have your shaft alignmet set up correctly.

John

Edited By bluebird on 11/08/2016 17:55:01

[Colin BishopModerator @colinbishop34627]

Richard,

Following on from John's point, (you might have already covered this), where do you propose to take up the thrust from the props. Full size vessels have internal thrust blocks but in models with exposed shafts it is commonly the practice to use collets on the shafts to use the outboard end of the stern tubes to transmit thrust to the hull. (astern power can be absorbed by a washer on the inboard end of the shaft against the tube.) Motors of course should only impart rotational energy to the shaft although I suspect that many people rely on their bearings and the motor itself to absorb thrust without realising it.

Colin

[Richard H DunnParticipant @richardhdunn]

I have a bronze bearing mounted in a block, and mounted either side of it are collars with grub screws to make adjustments, the block is located about 30% from the motor coupling.

[Colin BishopModerator @colinbishop34627]

Just like the real thing then!

Colin

[Richard H DunnParticipant @richardhdunn]

Thinking I have machined the A bracket all wrong.
I should have milled a flat on the boss at the correct angle to receive the legs so it holds it in the right angle, instead of cutting a concave surface on the end of the leg that can slide around.

Darn it I just found out I don't have a gear to mill, I have cutters and and end mill but not the chuck and my lathe is a 3 jaw one which it seems you should not put a milling cutter in.

 

Edited By Richard Dunn 3 on 13/08/2016 07:58:40

[Richard H DunnParticipant @richardhdunn]

Just some shots of the prop shaft arrangement to get any suggestions before I commit.

Here is an overview of the shaft from outside.

Cleaning of the planking inner surface is still not done aft and its not glassed in case I have to make any adjustments.

This is the thrust bearing without its stand and the gland on the motor room bulkhead

The gland is printed from ABS as are all blue parts and it has a tapered flange that matches the shaft angles, which means by rotating it I can adjust its optimal angle and lock it off with screws.

The bronze bearing inside the thrust housing.

This messy shot is the inside of the boss end casting that also houses a bronze bearing, seen here.

And finally the outer shaft parts that do not turn showing how it will sit over the boss end casting flange and be held  against the A bracket.

To finish off I will be making another gland with a threaded cap that compresses stuffing or O rings not sure which way to go yet…, this will be mounted aft of the thrust bearing and will be mounted on a watertight box to contain any leakage from the shaft space which can then be pumped out

Aligning shafts is a horrible job!!

 

 

 

 

 

Edited By Richard Dunn 3 on 14/08/2016 01:44:48

Edited By Richard Dunn 3 on 14/08/2016 01:51:55

[Colin BishopModerator @colinbishop34627]

Quite agree that aligning shafts is a horrible job, but not as bad as rectifying the situation where you find that you have inadvertently introduced a slight bend somewhere without realising it which is easy to do with long shafts. The shaft may appear to turn quite freely but makes a horrible noise when you apply standard revs to it!

I'm sure that the shafts in my Fishery cruiser were true when fitted and wonder if my problem was due to some tiny distortion in the hull structure once I had coated it. After all, if you just varnish one side of a supposedly stable sheet of plywood, it will tend to contract as the varnish dries. All wood hulls have moisture content and this can create havoc. I once helped out a friend by taking his model to to an exhibition as his health made it impossible for him to travel. It was a large model and he had built it in a very warm, dry centrally heated house. When I got it home, to my horror it started to curl up like a banana.

Colin

Edited By Colin Bishop, Website Editor on 14/08/2016 10:11:14

[Richard H DunnParticipant @richardhdunn]

Yeah that's one of the reasons I have such a heavy coating of Glass on the inside of the hull, it adds an immense amount of stiffness, I have stacked about 50kg on the hull midships and it has not dropped even .5mm while sitting on cradle so hope its all good.

That theory of do to one side as you do to the other is a foundation in woodwork, except I might add in the case of guitar building.

Some are here on our site I am still building.

http://dstruct-digital.com/index.php/guitars/

The inside is sometimes left bare but the instrument needs to be kept is a controlled case. usually I spray shellac

Edited By Richard Dunn 3 on 14/08/2016 23:04:59

Edited By Richard Dunn 3 on 14/08/2016 23:05:20

[Richard H DunnParticipant @richardhdunn]

I am now using 12v automotive fan motors and 100ah batteries for a run time of 5 hours.

I will be using a toothed belt drive geared 2:1

[Bat ManParticipant @batman91011]

I fly airliners as a job. I’ve also been building and flying model aircraft for the past 30 yrs and never ever touched anything that floats. Ever.

But this is just absolutely riveting!!! (no pun intended) I cannot for the life of me pull myself away from this build. I check it more frequently than the BBC news. Stunning work and absolutely great running commentary. A huge thank you for taking the time to post everything.

[Richard H DunnParticipant @richardhdunn]

Thank you but not sure I deserve all the compliments, plenty of mistakes being made.

Anyhow

I have had great success with the slot joint of the A Bracket , I made a jig and milled out the 4mm deep flat in the side of the bossing with a High Speed Steel Dremel cutter and carefully filed the strut to width and it is now a vice press fit, in fact I filed the round on the end in this picture with the 2 just pressed together.

as long as the expansion does not cause problems when braising I think I can safely say it will hold itself together for the Hard soldering session and I can do 2 struts at once.

The nice part is it holds the struts at exactly the right angle  fore and aft 15 degrees and will also keep the spread angle of 55 degrees in check as well.

Any thoughts?.

The Phosphor Bronze Liner bearings flange can be seen on the face of the boss facing the camera.

I will shape the strut before soldering but file the aerofoil later.

Edited By Richard Dunn 3 on 21/08/2016 05:36:02

Edited By Richard Dunn 3 on 21/08/2016 05:37:08

Edited By Richard Dunn 3 on 21/08/2016 05:38:27

Edited By Richard Dunn 3 on 21/08/2016 05:39:22

[BanjomanParticipant @banjoman]

That is a beautiful piece of work and very, very impressive!

Mattias

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