Topic: HMS Rodney (Read 19640 times)

derekwarner · « **Reply #75 on:** February 26, 2020, 08:08:06 am »

C-3PO ......RA Burt is listed as the first contributor to http://www.navweaps.com/Weapons/WNBR_16-45_mk1.php WEB document

So for clarification, if the listing from Burt is '65 degrees forward and 60 degrees aft of abeam'........this equates back to the convention offered in the document as 0.0 degrees train is pointing on the vessel fwd & aft axis [toward the vessel bow]

Having shown this, this arc of fire conflicts with the Official Document above.........but by some 5 degrees only.......

Train
0 degrees to 65 degrees of Train = Pointing Zone, Non Firing Zone - 65 degrees to 120 degrees of Train = Pointing/Firing ZoneElevation0 degrees to 65 degrees of Train = Non Pointing Zone, Non Firing Zone - 65 degrees to 120 degrees of Train = -3/+40 degree of elevation, Pointing/Firing Zone

Hope this makes sense

Derek

Martin (Admin) · « **Reply #76 on:** February 26, 2020, 05:57:31 pm »

Will the model have ~~target tracking~~ direction hold?

Colin Bishop · « **Reply #77 on:** February 26, 2020, 06:29:41 pm »

I think the quoted firing arcs vary between what is 'comfortable' which usually means well abeam, and 'possible' which entails the risk of damage to decks and fittings and to the bridge structure and which would only be contemplated in combat situations.

Colin

C-3PO · « **Reply #78 on:** February 27, 2020, 09:31:42 am »

Hi Martin,

I had not planned to install "direction hold" into this project. It's technically an easy thing to implement as I will have a digital compass onboard so when I get around to plugging the target tracking functionality into the boat I could also activate direction hold.

I have not actually sailed Rodney yet so I am not sure how responsive it will be to steering - that could well impact on the feasibility of direction hold.

I do have quite a long list of functionality yet to develop for this project so I reckon in will take another year for the boat to hit the water in all it's glory.

The gun elevation mechanism is in it's third iteration - my co-conspirator - Peter Ward has been working his magic with blocks of metal - machining them into what we hope will be awesome gun mounts - even at this scale it's a lot of kit to fit into a small space.

Thanks to Colin and Derek for their input on the turrets/guns - I can see it's likely that I will limit movement with these until I can get a clearer picture in my head - indeed I can see hours disappearing just thinking about the rules before coding them and it's time I just don't have at the moment.

We hope to have the boat ready for the Mayhem weekend for it's first outing - it won't be complete but it will allow us to evaluate where we have got to, learn lessons and regroup.

C-3PO

Radio Control Command System

This is slowly delivering functionality

Akira · « **Reply #79 on:** February 27, 2020, 02:29:12 pm »

C-3PO,OK, you win. I am well and truly mind boggled! Please don't stop. I kinda like it!

C-3PO · « **Reply #80 on:** March 08, 2020, 11:10:25 am »

Getting a response from a tablet/smart phone on the shore to a boat on the water seemed a bit far fetched when I started this.

Work is still in progress but it's come a long way.

The LCD screen shows the parameters received by the radio receiver on Rodney - 3 x turret headings / 9 x gun elevations / 9 x armed-ready to fire status. These are then distributed via a network on the boat- the LCD is connected to the network to give visual feedback of what is going on.

To breathe life into the concept I then need to connect devices (gun elevation servos, smoke production units, gun flash leds, turret rotation steppers and sound system) to the network for them to obtain their instructions/parameters. - You can see the latency is short.

https://youtu.be/VrlplSqj2mc

https://youtu.be/VrlplSqj2mc

Regards
C-3PO _._

Martin (Admin) · « **Reply #81 on:** March 21, 2020, 09:29:35 am »

Amazing work, impressive patience!

( NB: How was air site direction passed down to the AA batteries? )

ballastanksian · « **Reply #82 on:** April 06, 2020, 02:20:08 pm »

By the mid thirties land based and even mobile AA units had systems that allowed the gun layers to simply 'follow my leader' instructions fed from the central predictor unit sent out via cables to the guns.

Each of these had dials with motors controlled by the predictor unit that the gun layers had to match by turning their handwheels/cranks to keep the pointers on the dials in tune with those controlled by the predictor unit.

On a warship, the weapons and directors were linked by electrical conduits similar to how the main guns were controlled.

C3PO's work on 'Rodders' and Bob's Agincourt are the same but in miniature and with a pooter brain rather than crewmen spinning handles and wheels.

Re timescale, it is your interest and so takes as long as it takes

C-3PO · « **Reply #83 on:** May 25, 2020, 07:38:24 pm »

HMS RODNEY

3 turrets turning, 9 guns elevating

https://www.youtube.com/watch?v=jlO-TLJ3TJE

https://www.youtube.com/watch?v=jlO-TLJ3TJE

C-3PO

raflaunches · « **Reply #84 on:** May 25, 2020, 07:43:07 pm »

Hi C3PO

Stunning video and of course workmanship. I’d say that’s everything near enough scale speed in traverse and elevation. Amazing set up and I look forward to the installation in to the Rodney.

derekwarner · « **Reply #85 on:** May 25, 2020, 11:32:14 pm »

Whilst concise rate of speed/degree tables are provided for these Mk14 Gun Mounts, and applying mathematical scaling is relatively simple, however the task then is to get our mind to accept what we see is correct?

So I again suggest speed is such a terrible unit to visually scale........

......however must agree with Nick that the mounts train and elevation visual rate [of speed] looks to be what we could imagine as

When the turrets are installed in the hull .....all the rest of the above deck superstructure, funnels, aerials, light etc..etc are all open to our eyes & multiple stationary images are sent to the mind for processing. There is/are only so many, or so much [even if stationary] that our mind can only adsorb in 'Bits' of information per unit of time called 'Cortical Columns'...

https://www.sciencedaily.com/releases/2017/06/170608145602.htm

[well worth a moment to read as it applies to our daily life]

Derek

C-3PO · « **Reply #86 on:** May 26, 2020, 12:41:26 pm »

Nick/Derek - the speed of elevation/rotation is configurable

Derek - thank you for the info - I will see if I can understand it!

Currently the test rig on my desk is using servo's from my junk box!!! - They are ruff(!)

The final speed calibration etc will be done on the new digital brushless servos ($$$) that I have from HITEC which are way smoother but then they will be working hard pulling brass barrels connected to pipes supplying smoke - the video is simply plastic straws.

I will be aiming for speeds as per the info below kindly supplied by Colin Bishop

The rotation is super smooth as it's using a nema stepper motor @ 12800 steps per revolution

C-3PO

C-3PO · « **Reply #87 on:** May 21, 2021, 09:29:57 am »

Poor HMS Rodney has sat neglected for many months - at the start of the pandemic I thought I would have loads of time on my hands to crack on and get this finished - reality was very different...

Since having started playing with stepper motors and turret turning the consistent problem/headache in the background is that there is no direct feedback from "switch on" as to the position of the stepper - unlike a servo.

It's possible to go through a calibration sequence when you "switch on" and then all being well (assuming you don't loose any steps) you do know the current position of the stepper.

I came across a very cheap sensor that works in conjunction with a diametrically polarised magnet attached to the end of the stepper shaft and then locating the sensor close to the end of the stepper shaft but not touching it.

Results so far are astonishing - definitely accurate to 2 degrees and possibly accurate to 0.5 degree (further testing required)

Regards
C-3PO

ballastanksian · « **Reply #88 on:** June 07, 2021, 01:07:40 pm »

It's good to see you about with some development work!

C-3PO · « **Reply #89 on:** June 07, 2021, 03:58:10 pm »

Hi ballastanksian,

Thank you for the comments....

Well in the background I have been testing the sensor to monitor the stepper position - accuracy so far is 0.25 of a degree - just mindblowing...

The sensor can be calibrated - the kit to achieve that arrived today.

https://www.youtube.com/watch?v=JFJegC5Ff1M

I wrote a quick program to send the stepper 200 steps - record it's postion and then go back 200 steps and do the same - the output is shown below in degrees - very pleased with that result as in reality I just wanted nearest degree.

So along with a new "gun smoke" system I aim to ramp up the project to get it on the water as soon as possible

Regards
C-3PO

ballastanksian · « **Reply #90 on:** August 18, 2021, 04:24:21 pm »

That's pretty accurate! I look forward to seeing all your developments as well as the ship to carry them on/in.

Tworrs · « **Reply #91 on:** April 18, 2022, 10:31:25 pm »

Very impressive guys.

ddmckee54 · « **Reply #92 on:** April 20, 2022, 07:29:42 pm »

C-3PO:

Something's not right here. When you said your program moved the turret 200 steps and recorded its' position, and then moved 200 steps back and recorded its' position, did you mean that it moved 200 steps CW from 0, then 200 steps CCW from 0? This would be a total of 400 steps. The values recorded differ by about 11°. Using your 12800 steps/revolution, 400 steps is 11.25°.

If you only moved a total of 200 steps, then your sensor scaling might be double what it needs to be, i.e. moving 6400 steps might indicate 360° of rotation instead of 180°. The sensor is very consistent though.

Don

chipchase · « **Reply #93 on:** April 20, 2022, 10:26:47 pm »

HMS Rodney

ballastanksian · « **Reply #94 on:** April 23, 2022, 09:15:52 pm »

Gorgeous ship model

John W E · « **Reply #95 on:** April 24, 2022, 09:09:44 am »

Hms Ajax and Hms Nelson (modelboatmayhem.co.uk)

Geoff · « **Reply #96 on:** April 25, 2022, 06:05:02 pm »

Looking good, how's the gunfire system going?

Cheers

Geoff

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Author Topic: HMS Rodney (Read 19640 times)