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Author Topic: T.A.R.G.E.T - Rotating Seven gun turrets?  (Read 79241 times)

Colin Bishop

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Re: Rotating seven gun turrets?
« Reply #25 on: December 24, 2016, 10:30:06 AM »

 Getting the turrets to train on a ship like Agincourt is certainly worth the effort. From what has been said above it does look like there are two options. Firstly, and relatively(!) simply, is to use an electro mechanical system to move the turrets to train out on either beam and return to the centreline. This is still quite complicated given that they are facing in different directions. It is however a practical option.
 
The second option is the computerised or Arduino route which opens up quite exciting and possibly commercial possibilities as it should be able to develop a turret training module which could be used on any warship and need not be specific to Agincourt.
 
I am not familiar with Arduino but I have done plenty of programming in my time and that side of it should be reasonably straightforward. What is required is a separate module for each turret consisting of a control board and servo mechanism. The control board should be capable of being programmed to set the maximum degree of travel in each direction independently as turrets in early dreadnoughts and other vessels may only have limited training on one side. We would refer to these as direction 1 and direction 2 so as to suit turrets initially facing forward and aft respectively.
 
In its simplest form a central processing unit in the model would be sent a command from the TX specifying the bearing of the target relative to the heading of the ship. This would be passed on to the individual turret module together with the required direction which would examine it to see if it falls within the training limitations of that turret for the specified direction. If so then the turret would train round to that bearing. This would in fact reproduce what the director control on the original ships actually did, with the turret crews lining up pointers to match the director layer instructions. A sub routine might also be used so that if the degree of training specified is outside the turret’s programming the turret would still train round as far as it could in that direction.
 
The icing on the cake would be to introduce a top level whereby the TX operator would specify an absolute direction or position of the ‘target’. The processing unit in the model would identify this by means of an onboard electronic compass or GPS and compare it with the ship’s heading on a dynamic basis thus modifying the signals sent to the turrets with the effect that as the course of the model changes the turrets continue to ‘lock on’ to the ‘target’ Now that would be really impressive!
 
A system like this could be designed, built and sold in the same way as other electronic component sets and as long as the cost could be kept down I think there would be a pretty good market for it. A lot of the technology is already is use in other fields of modelling and elsewhere.
 
Colin
 
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g6swj

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Re: Rotating seven gun turrets?
« Reply #26 on: December 24, 2016, 11:02:42 AM »

All that Colin has described is within reach of all of us right now - you just need to want to do it!

A cloned Arduino costs less than a tenner

The concept of Arduino is making technology accessible to all - it brings an amazing, powerful and SIMPLE solution to your desktop.

If you can type basic text, connect a USB cable to a computer then you are ready to use an Arduino.

If you have a few minutes then watch this video - it might dispel some of the myth about how complicated it isn't!! - most programs are only a few lines long

https://youtu.be/d8_xXNcGYgo?list=PLGs0VKk2DiYx6CMdOQR_hmJ2NbB4mZQn-
 or

http://rchub.co.uk/thinking-about-getting-an-arduino-watch-this/

or perhaps hit Youtube  and search Arduino or Google Arduino - you will see how BIG this little board has become.

As with most things these days there are thousands of people on forums willing to help you when you get stuck.

Want some more inspiration then browse www.rchub.co.uk - a growing resource of web based Arduino and Radio Control articles, ideas, examples etc

You will be amazed at how your creativity is awakened when you understand the basics  - it will certainly stimulate your grey matter!

Have fun and Happy Christmas

Jonathan

Quote
Here is an example program that blinks an LED

void setup() {
  // initialize digital pin 13 as an output.
  pinMode(13, OUTPUT);
}

// the loop function runs over and over again forever
void loop() {
  digitalWrite(13, HIGH);   // turn the LED on (HIGH is the voltage level)
  delay(1000);              // wait for a second
  digitalWrite(13, LOW);    // turn the LED off by making the voltage LOW
  delay(1000);              // wait for a second
}

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derekwarner

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Re: Rotating seven gun turrets?
« Reply #27 on: December 24, 2016, 11:38:23 AM »

Jonathon...I do not dispute the valued comments in the technology you offer here ....however this scale Capital Warship would be steaming at some 30+ scale knots when she aimed her broadside at the Enemy

Unless this scale scenario is going to be conducted in a real river or stream some I km long :-) the players here are kidding themselves playing in a 25 m long swimming pool  {-)

Again I suggest we are not conducting an orchestrated ballet movement of Naval Ordinance   <*<

Derek

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Martin [Admin]

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Re: Rotating seven gun turrets?
« Reply #28 on: December 24, 2016, 11:54:33 AM »

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roycv

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Re: Rotating seven gun turrets?
« Reply #29 on: December 24, 2016, 11:58:24 AM »

Hi, a simple solution might be to buy 10 off 9gram servos (£10 for 10 servos inc p&p, ex China).  Use one to drive each turret, connect them all up in parallel so they have just one lead to go into the receiver. Then  choose a channel that can position the turrets (rotating knob or lever) and leave them in desired position.
Should work and you have 3 servos left over.
I am working on a similar system for operating my points on a model railway layout.
Sorry Bluebird a bit the same as your offering I did not realize this was the second page of the thread!
regards Roy
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Colin Bishop

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Re: Rotating seven gun turrets?
« Reply #30 on: December 24, 2016, 12:08:09 PM »

Roy, the problem with that is that all the turrets will move by the same amount so with the layout on Agincourt, except at the full abeam positions, they would be pointing all over the place!

Colin
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John W E

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Re: Rotating seven gun turrets?
« Reply #31 on: December 24, 2016, 12:28:35 PM »

hi all

I have been racking my brain, seeing if there is an alternative method to rotate these turrets using electric motors and micro switches - or - using a modified servo tester to rotate servos,. 

To be honest after watching the videos that were posted earlier on regarding Arduino technology is looking the best.   I dare not ask for another Christmas pressie :-) as I have several modelling bits from Mr Claus and when my credit is clear I am going to invest in a starter kit for the Arduino .. to help others understand the problem here is a picture of the layout of the main turrets of the ship.

The other thing I have noticed - this is a Tyne built ship, that was to be sold to foreign powers.
john
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Colin Bishop

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Re: Rotating seven gun turrets?
« Reply #32 on: December 24, 2016, 12:55:39 PM »

John, yes, that is the conclusion I have come to as well. People naturally focus on the electro mechanicals of making a turret rotate but the real problem here is synchronising the movements of seven turrets, four of which start off facing in different directions to the other three, so that they consistently bear in the same direction relative to the heading of the ship.

On the real ship each turret had its own 'brain' in the shape of the  turret crew so you can argue that it makes logical sense to reproduce this now that the technology is readily available and cheap. We need to move away from the gears, elastic bands and cord based approach which would require a Heath Robinson type solution to what is in reality a far simpler method but which requires us to take on board a new skill but a lot of modern electronics is effectively plug and play so it's not really as bad as it initially seems.

I do think there is a commercial opportunity here though for someone willing to seize it using off the shelf components. After all, who makes their own speed controller these days when you can just buy them for £20 and plug them in?

I don't build warships but if I did and there was something on the market at say £15 per turret plus a controller I would certainly be tempted.

Colin
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g6swj

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Re: Rotating seven gun turrets?
« Reply #33 on: December 24, 2016, 12:59:20 PM »

I would probably go for stepper motors but servos would be ok

Whether moving servos all in synch, at different speeds or whatever combination you fancy - it is easily achieved with an Arduino

https://www.youtube.com/watch?v=-B-jwBnsQPI

Servo movement for <£10 total plus cable it couldn't be simpler

Full explanation and working code http://www.lamja.com/?p=504
*Note - this is a complex solution due to the accuracy involved with timing and the way it's achieved

Regards
Jonathan
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Bob K

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Re: Rotating seven gun turrets?
« Reply #34 on: December 24, 2016, 01:51:35 PM »

There is a wealth of ideas here.  Basics are that this is a ship of two halves so having a receiver in each half, operating from the same transmitter channel, makes practical sense.  Cutting the number of servos per Rx and eliminating inter-hull wiring.  Servo "stretchers" usually appear to work up to 160 degrees. I need 180.  So I am leaning towards a simple 2:1 gear set for each turret rather than drums and string. 

Timing is the next question.  I want them to turn realistically slowly, and not all at the same speed. A P96 operating two random turrets each would do that, and as I only need about 5 seconds hopefully will not judder appreciably. Set each P96 to a slightly different time and depending which turrets they operate could give the desired visual effect. 

The computer solution could be the most elegant but having watched the various video quoted I would avoid that unless I could get it ready programed and servo-connected.  Would that be one Arduino per turret, or one for each half of the model?

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g6swj

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Re: Rotating seven gun turrets?
« Reply #35 on: December 24, 2016, 02:16:51 PM »

Bob,

I am willing to work with you to get a "pre-programmed" solution if you are happy to make a donation to the RNLI.

All you need to do is specify exactly what you want and I confirm it's deliverable and the cost (components).

One Arduino could do all the servos, slow them down, trigger the independant movement etc.

The only question would be what complications/solutions are involved with a boat of 2 halves!

Regards
Jonathan
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John W E

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Re: Rotating seven gun turrets?
« Reply #36 on: December 24, 2016, 02:27:03 PM »

hi ya Bob/Jonathan

Looking at the drawings I posted of the ship; wondering would it be possible to split the hull just after the 5th turret in the centre?  that is counting the turrets number 1 at the stern and number 7 would be at the bow?

This would mean that we have 5 turrets in the stern section of the model and doing it this way the majority of the cables for the servos/motors driving the turrets would be all kept together in one half of the hull.   We would only have to have a multi plug for the 2 turrets in the bow section - less wiring and things to worry about.    Just a thought.

Don't forget though, when we split the hull we also have side armament to take into consideration - i.e. obviously you cant split the hull through the middle of a gun housing.

John
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Colin Bishop

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Re: Rotating seven gun turrets?
« Reply #37 on: December 24, 2016, 03:47:53 PM »

Well, it has piqued my interest to the point that I have downloaded John Boxall's book to my Kindle for a bit of Christmas reading. Might invest in a starter set after that.

Colin
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malcolmfrary

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Re: Rotating seven gun turrets?
« Reply #38 on: December 24, 2016, 04:12:52 PM »

While it is very possible that turrets on large capital ships could be trained over 90 degrees from the centerline, were they?  I read somewhere that letting big guns off at anything other than a full 90 was liable to damage the ship doing the firing more than the target due to the blast from the muzzles.  If that is the case, then 90 degrees each side is enough and it then needs some thought regarding elevation.
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Colin Bishop

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Re: Rotating seven gun turrets?
« Reply #39 on: December 24, 2016, 04:31:22 PM »

On the early dreadnoughts the wing turrets could fire within about 10 degrees of the dead ahead position. Anything else outboard was generally OK although some blast damage was to be expected. The exceptions were axial superfiring which could not be carried out until the turret sighting hoods were located at the rear of the turrets (0riginally the front) and cross deck firing by wing turrets which did cause blast damage and strained the hull so would not normally be done unless the turret on the opposite side had been knocked out.

Any firing where the muzzles were over the deck was likely to result in damage to the deck and its supports and HMS Rodney sustained a lot of damage in this fashion when engaging Bismarck. The later American battleships had floatplanes mounted on stern catapults and these did not usually last long unless they had already been jettisoned!

Colin
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John W E

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Re: Rotating seven gun turrets?
« Reply #40 on: December 24, 2016, 04:52:58 PM »

okay then; the last 2 areas which we haven't explored are micro pneumatics and also hydraulics.   I have noticed after a web search a lot of these systems are used in robotics and also artificial limbs and so forth.  We all know they can be very precise and smooth in movement.  The only downside I can see at the moment may be the air supply.  The storage tank would have to have a pump to replenish the air supply.  This would obviously be a drain on the main batteries or whatever.   Going the other way and using hydraulics; the down side there would be the connections between the two halves of the hull. because every time you break the hull and reconnect it, you would possibly re-introduce some air into the hydraulic system.

Another bit of food for thought.

John
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Colin Bishop

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Re: Rotating seven gun turrets?
« Reply #41 on: December 24, 2016, 05:15:13 PM »

Interesting point John. The original ships had hydraulic engines for training and usually elevation. The battlecruiser Invincible was originally fitted with two different electrically powered turrets as an experiment but these proved to be unsuccessful and no improvement over the standard hydraulic power which was smoother. Maybe the same would apply to models as well.

Colin
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Re: Rotating seven gun turrets?
« Reply #42 on: December 24, 2016, 06:57:41 PM »

To follow through with the KISS principle, duplicate whatever system of control is used in the fore and aft sections. Two Arduinos or two hydraulic systems or two banks of servos. Too many through hull connections could be prone to failure due to water splashing while separating the hulls at the end of a run, not an unknown situation. Also, half a ship would fit easier on a work bench. If it is self contained electrically, it will be easier to set up, not requiring the other half of the ship to be connected for any electrical work.
The aft, radio control section of my 100" SS Ohio is only 26" long, very manageable. While the forward pyro control unit is actually modular, in a 8"x 6" box, while the entire hull section is only 44" or so long. All easy to work on.
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Bob K

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Re: Rotating seven gun turrets?
« Reply #43 on: December 24, 2016, 08:45:15 PM »

Self contained independent halves is the way to go, for all the reasons you say.
Incidentally I did read right through your interesting SS Ohio build thread to see how you accomplished the actual hull joining.

My intended project must separate at exactly half hull length as even then the halves will be a tight squeeze in my Agila, both parts travelling side by side.  Before anyone suggests it, I had considered WW1 MKI tank sponsons on the rear passenger doors, but that may have upset the M.o.T. testers modifying the vehicle to seven and a half feet wide.
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Re: Rotating seven gun turrets?
« Reply #44 on: December 24, 2016, 09:19:41 PM »

Hi Bob
you have been many good ides . Have a look at this radio . it comes as 16ch but can be expanded to 32ch . You could easily assign single or banks of guns to a ch


john
https://www.frsky-rc.com/product/pro.php?pro_id=143


 
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derekwarner

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Re: Rotating seven gun turrets?
« Reply #45 on: December 24, 2016, 10:42:21 PM »

As Colin notes with 'hydraulic drive', this essentially was an electro hydraulic mechanical drive…..the original vessel turret motion was provided by a DC electric motor driving a hydraulic pump which drove a hydraulic motor connected to a high ratio helical speed reducer which for elevation rotated  an outboard precision worm which was directly connected to a large elevation worm wheel arc. The train motion was of similar design. One point to understand here is that the electro hydraulic mechanical drive system were designed and controlled with an accuracy to point the barrels at degrees and minutes of position

Sub miniature [1/12 scale] true hydraulic pumps/valving/linear actuators and geared motors are available and used exclusively in RC off road equipment, however having spent a lifetime in mercantile marine, industrial and Naval hydraulic systems, I would suggest these components are grossly out of practical scale for a 1/96 scale vessel

The same would apply to any fluid pneumatic system which would rely on an air accumulator. Miniature fluidics [pneumatic] valving is available, however converting this to rotary or linear movement is problematical

The every kind offer from Jonathon to assist with the basic design going down the Arduino path and would be worthy of consideration, however as he states.....a full set of parameters would be required.....this must include the intended scale waterway and speeds and turning circle for the vessel. An advantage here would be the facility to input pointing and non pointing zones or firing and non firing zones

[Courtesy of Wikki]…..[It is often stated that the seven turrets were named after days of the week rather than the letters usually used in the Royal Navy.[10] They may have been known by crew members by such a designation, but in official literature the turrets were numbered 1 to 7.[11] John Roberts has informed the editors that the as-fitted plans of Agincourt from 1918 reflect this usage.[12]

[Reading this surprised me as I had assumed the nomination would have been A, B to X &Y etc] So No 1 turret is foremost at the bow, then working back numerically to the stern

No 1 & No 2  turret would have a full say 80 degrees +/- to port & stdb pointing and firing zones, No 3 turret ...would  have the same extreme 80 degrees +/- to port & stdb pointing & firing zones, however at approaching say +40 degrees to axis would enter a non pointing zone - non firing zone until  -40 degrees was reached

To better understand, a non pointing zone is one in which the system will not allow the mount to make a physical stop/end of movement with the barrel pointing in this zone. Naturally mounts  No3 & No 4 etc will need to be traverse or be driven through the arcs on non pointing zones, however the mechanical computers in these mounts precluded the mount to stop, or fire

May well be worth going back over a long Battleship thread here on MBM from Geoff in his trials and final gun mount systems he installed,

As you go down the path of controlling the speed of the turrets will open Pandoas box, in that true scale speed of turret movement will to the human eye and mind not be appropriate……yes certain non scale movements will be needed

Still a very interesting subject........Derek

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Derek Warner

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Colin Bishop

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Re: Rotating seven gun turrets?
« Reply #46 on: December 24, 2016, 10:50:59 PM »

"this must include the intended scale waterway and speeds and turning circle for the vessel."

I'm not quite sure what you are getting at here Derek - could you explain a bit more?

Colin
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derekwarner

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Re: Rotating seven gun turrets?
« Reply #47 on: December 24, 2016, 11:17:48 PM »

Merry morning Christmas wishes Colin O0......

This  question......the really depends on how much scale Bob wishes to be created......battleships of this era did not fire broadsides at close quarters and still speeds of Nelson or Drake as such, however these Dreadnaught Class vessels would fire at a vessel on a converging or intersecting target point of some considerable distance and not two vessels steaming in opposite directions

If Bob intends to use his 2m long vessel in a 20m long x 5m wide home pool, the vessel at a pre determined part angular broadside would need to be made at an imaginary target 200m away. The amount of concentration to the train positioning of the individual 7 turrets would probably need the vessel to be near stationary in that 20m pool

From experience, a 2m long scale vessel would need some 3 x 3 point turns to reverse direction in that 20m long x 5m wide home pool

Derek
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Colin Bishop

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Re: Rotating seven gun turrets?
« Reply #48 on: December 24, 2016, 11:45:02 PM »

Still waiting for Santa here..... ok2


I see what you mean as far as Bob is concerned. However I was rather looking at things on the basis of the model swanning around on a biggish pond/lake in the usual way with the skipper demonstrating that the turrets could train and elevate and also maintain a bearing on the hypothetical target irrespective of what course the model is steering. The full size equivalent might be the behaviour of Warspite at Jutland when her steering jammed. Although the ship was hoing round in circles the msin armament was still aiming and firing at the enemy line.


Bedtime now!


Colinm
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Re: Rotating seven gun turrets?
« Reply #49 on: December 25, 2016, 08:07:08 AM »

Whilst I am an Arduino advocate you might want to put this on the late Santa request list - Maestro Servo Controller available in 6,12,18 and 24 channel versions (£20 for 6ch - £35 for 24 ch)

Programmable via your computer with on screen easy to use interface it creates a sequence of instructions in the form of a script that can be saved and run from the board stand alone when not connected to the computer.

https://www.pololu.com/product/1352

Regards
C-3PO
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