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[marmoi]

The question now is should I produce all the secondary armament this way? 

[marmoi]

Not forgotten, but been a bit stalled as the electronics to control the turret movement have had the habit of blowing up on me, so I have rung a friend who is working on the development.

In the mean time I have sat down to look at the Walrus which is another part of this project that has been put aside due to frustration - everytime I tried to do the stringing on the wings then models seemed to collapse.

This time armed with 0.2 Nickel Silver wire things worked a lot better!!! 

I also cut the original cast cockpit off and made a new Perspex canopy and re-glazed it with microstrip. Engine detail was enhanced and the rear gun postion detail added.

I also wanted to make the correct launching mechanism for the Walrus as this is often left of models, and after a couple of attempts got the geometry correct for this.

I am in the process of creating my own transfers and applying them.

Mark

[Dave13]

Very nice Marmoi I love the Walrus

[richtea]

Good to see the progress that you have made,
that Walrus is a work of art in it's self.
Regards
Richard 

[marmoi]

Decals all finished, Plane and launching trolley assembled and while I had a spare moment the pilot and two ground crew painted.

I also mocked up a little diorama to help store the model as it is prone to tipping over without support! 

Now to have a look at the recovery crane.

[Marmoi]

Ok, time to do a bit of catching up.

The build has been continuing, but due to work, the forum being down and buying a renovation project in France, updates have not been possible this year.
But now I have a spare moment I can tell you where I have got since Christmas.
Over the Christmas period I sat down and worked on the outstanding issue of the main turrets and their control. I had three ideas for this model that I wanted to achieve;

1.   Turret movement to any position I wanted.
2.   Turret to stay trained on target once set.
3.   Turrets to return to station if target/ship moves out of firing arc.

Many model warships over the years have been able to turn their main turrets, this is not difficult and can be done in a number of ways. However the guns normally just turn to broadside and then return, this is not what happens in real life and real life is what I am trying to achieve.

In real life the guns will train to either side and then once locked on target will remain on target even if the ship alters course until such a time as they cannot fire and will return to their original position until such time as they can be trained again.

I have achieved the turning and I have used a model helicopter “heading lock” Gyro connected to a speed controller to control the movement of the turrets once locked on target. See video at link below;

http://www.youtube.com/watch?v=YIgZI2mLhOg

[Marmoi]

However I now wanted to control the actions of the turrets when they reach their limit of firing arc and then combine the lot!

Arc of firing for turrets Left and Right

[Marmoi]

What was required;

Three Turrets to start off in line with the centre of the ship.

[Marmoi]

One of two possible momentary contacts closing (Left or Right signal) would give the signal to turn the turrets left or right.

Signalled to turn Left

[Marmoi]

The turrets would continue to turn (independently) until they each close micro switches, which would then cut the power to the motors (12V DC). This would be the broadside position.

[Marmoi]

The Gyro would then be activated and control the turret movements (with manual overide from the transmitter). The GYRO is currently activated on the transmitter.

[Marmoi]

If the central turret could trigger any of the end of firing arc micro switches, then the turrets should be removed from Gyro control and return to station, to await further instructions, in  their original position in line with the centre of the ship.

[Marmoi]

Again controlled by micro switches at the centre of travel. Once all three are back in position the system should reset to its original state.

These were what I thought were the inputs and outputs required;

[Marmoi]

Now feeling brave and with a bit of time to experiment, I gathered a few components together and proceeded to produce a test board to try this out, after a short time of working it blew up as I put it through its paces. Having realised what I had probably done wrong I built a second board and yes you guessed it, I blew that one up as well.

Obviously my logic was not and layout of relays was not going together well. So it was time to consult a friend who designs and builds one of circuits for a living! He told me what I was missing was a micro controller to control the actual relays and make sure everything did what I wanted when I wanted. Now not being experienced in such circuits he volunteered to design and build the circuit for me and after a few weeks presented me with a solution.

[Marmoi]

While the circuit was being built I worked on the design of the turret base as I had a lot of micro switches to mount along with the motors and gears. I built the design up in CAD over a weekend and soon came to the conclusion that if I made this in the traditional workshop method it would probably not be strong enough to support everything and endure me testing out the workings.

[Marmoi]

So I went down the route of using 3D printing again using a strong Nylon material.

[Marmoi]

This proved to be an excellent choice as the finished articles were indeed very strong and needed no extra support to mount the motors and switches.

[Marmoi]

With the major parts in hand it was now only necessary to build a test board and wire the lot together (Only! ).

[Marmoi]

I found I had to use a Bobs Board for the Gyro control of the turrets as I could not find an electronic speed controller that could handle the output from the digital gyro.

[Marmoi]

After a couple of false starts the turrets began to operate and with a couple of changes/updates to the programming the turrets stopped breaking of the guns and I looked for a way to elevate the guns individually to give that final look of realism.

The answer to my problems was found on Hobby King in the form of under carriage controllers.

[Marmoi]

The guns and turrets are now under going rigorous testing to make sure they do not go wrong and crash into the rest of the model.  

[essex2visuvesi]

Speechless!

[Marmoi]

Well take a deep breath as there is more 

[Marmoi]

So what next?

Well I am still working on the main superstructure and its modifications during the re-fit, with a mind to having a lot of the parts photo etched. So I turned my attention to the next large piece that needed looking at the Funnels.

The original builders plans showed that they had proposed twin in line funnels as below;

[Marmoi]

However in-line with practice during the 30’s I decided that would give this area a makeover and replace the twin funnels with a single trunked funnel and as I have wanted to build one of these for a while and I also wanted to do it correctly and build it twin walled.

I drew up the new funnel and was amazed at its size.