Model Boat Mayhem
The Shipyard ( Dry Dock ): Builds & Questions => Navy - Military - Battleships: => Topic started by: C-3PO on July 29, 2019, 03:07:02 pm
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Working on the smoke system for HMS Rodney - https://youtu.be/ceF5wZMuXKA (https://youtu.be/ceF5wZMuXKA)
(https://modelboatmayhemimages.co.uk/images/2019/07/29/Smokin.jpg)
C-3PO
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HI C-P30
lookin at the amount of smoke you are makin I just wonderd what the source of the smoke is ? as I have fitted a smoke unit in my Norfolk an its a water based unit an she looks quite good smokin on the water but does not make this amount of smoke you are makin an have you built Rodney yet an is the build on here ?
chris
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Hi Chris,
The smoke source is water/glycerin (85/15).
The method used to produce the smoke is still in development and I am not in a position to share the details (sorry) but is loosely based on the same method as commercial smoke machines.
I anticipate even more impactful smoke by the time the project is finished - for all 9 guns - time will tell...
PM Re HMS Rodney
Regards
C-3PO
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Hi Chris,
The smoke source is water/glycerin (85/15).
The method used to produce the smoke is still in development and I am not in a position to share the details (sorry) but is loosely based on the same method as commercial smoke machines.
I anticipate even more impactful smoke by the time the project is finished - for all 9 guns - time will tell...
PM Re HMS Rodney
Regards
C-3PO
HI C-3PO lookin forward to seein her on the wet stuff an guns firin will be a cracker of a model an as she's big will look very realistic :-))
chris
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Ballasting accomplished 22kg
Now the magic starts... a joint venture between an expert modeller/engineer and an Arduino wizz
(https://modelboatmayhemimages.co.uk/images/2019/09/14/IMG_8242.jpg)
C-3PO
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Hi C 3 PO all looks Very good I can see you are the man for it .Looks very nice on the water cheers John V
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Hi - Can anybody point me in the direction of a set of plans (ideally/1/96th) for HMS Rodney
Thank you
C-3PO
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Hi C-3PO
Other than the National Maritime Museum Plans Section, the only other place I can think of is Profile Morskie. They can print off their plans at any scale you require. And they do one of HMS Rodney.
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There was a topic back in 2008.
https://www.modelboatmayhem.co.uk/forum/index.php?topic=8756.0
Colin
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Hi Colin/Nick,
Thank you for the info...
Need to find more body parts to sell having purchased some beauties ($$$) from Shapeways & John Jaynes for our HMS Rodney project.
C-3PO
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Crane under construction (supplied John R Haynes)
(https://modelboatmayhemimages.co.uk/images/2019/10/11/PW_001.jpg) (https://modelboatmayhemimages.co.uk/image/JpNOP)
C-3PO
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Looking really good :-))
Bob K
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Hi Bob,
Thank you - the credit for the build (building on what Mr Dean had already achieved) has to go to Peter my co- conspirator with this project.
Regards
C-3PO
(https://modelboatmayhemimages.co.uk/images/2019/10/11/SAM_1511.jpg)
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I am in awe @ Peter's build ability - the crane and catapult (John R Haynes) are a work of art...
(https://modelboatmayhemimages.co.uk/images/2019/10/14/PW_002.jpg)
C-3PO
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HMS RODNEY - Smoke system development
I now have the production of smoke fully under microprocessor control - this allows me to vary the density, plume shape and length of time smoke is produced.
In the video smoke is set at about 45% density - turned right down so I can still breath in my den...
Can't wait to see all 9 guns firing broadside! - https://www.youtube.com/watch?v=bRVVhIVQlbY&feature=youtu.be (https://www.youtube.com/watch?v=bRVVhIVQlbY&feature=youtu.be)
(https://modelboatmayhemimages.co.uk/images/2019/10/14/rodders.jpg)
https://www.youtube.com/watch?v=bRVVhIVQlbY&feature=youtu.be (https://www.youtube.com/watch?v=bRVVhIVQlbY&feature=youtu.be)
C-3PO
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Hi C3po it's John V I think you are very clever of putting it all together . Keep up the good work .Cheers John V
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Never realised you could have so much fun smoking out the joint!!! I have just pressed the order button to allow smoke production for all 9 guns - gulp
Inserting a brasss pipe at the end of the tubing has had a dramatic effect on the shape of the smoke plume.
The smoke is being created about 1 metre from the exit point - I am pleased with the way it travels in the pipework
Next experiment is to increase smoke density...
https://youtu.be/83ShklBRdKI (https://youtu.be/83ShklBRdKI)
(https://modelboatmayhemimages.co.uk/images/2019/10/18/smoke-2.jpg)
https://youtu.be/83ShklBRdKI (https://youtu.be/83ShklBRdKI)
C-3PO
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VERY CLEVER that looks great an very realistic when done you wont be able to tell that from a real battleship if there were some still around
chris
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HMS Rodney
Gun elevation is proving challenging but slow porgress is being made - only another 8 to go !!!
https://www.youtube.com/watch?v=0ksB9zvxoks&feature=youtu.be (https://www.youtube.com/watch?v=0ksB9zvxoks&feature=youtu.be)
(https://modelboatmayhemimages.co.uk/images/2019/10/20/2019-10-20_22-44-11.jpg)
https://www.youtube.com/watch?v=0ksB9zvxoks&feature=youtu.be (https://www.youtube.com/watch?v=0ksB9zvxoks&feature=youtu.be)
C-3PO
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Very effective movement but the gun appears to be under the turret in the video.
You probably already know that Rodney & Nelson fired salvoes with two guns of one turret and one of another. Rarely broadsides. It is all documented somewhere!
Colin
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Hi Colin,
Thank you for the info re the salvo firing - I did not know that - very interesting - I will aim to replicate that functionality on the model
You are correct re the turret location, sitting on to of the guns - it's temporary
I have not finished the cut-out yet and dropped the top on the workings to hide the "chewing gum and elastic band" mechanics under the hood - there aren't even proper bearings in this example and the gun judders a little - all will be solved in time...
Engineering is not my thing and I struggle with the basics. This is why for me this project is really quite exciting as working with an engineer and expert modeller (Peter) the end result should be a thing of beauty - he is currently working his magic with the super structure.
He will no doubt smile and put right my amateur approach to the workings of gun elevation - I just wanted to see what was possible - and what space we had to squeeze in the kit for elevating each gun individually - whilst working @ 1/96th scale provides on first impressions a lot of space it soon seems to evaporate.
Regards
C-3PO
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Very interesting indeed. As a word of caution if you are using non flammable fog fluid do be aware that unless its vaporized properly it can leave a residue which is in fact flammable. This is what happened to me with early trials with Iron Duke and led me down the PTC Thermistor route as a heat source.
Just to prove it dip a fire proof wick in the fog fluid and hold it over a gas flame and it will burn - not a lot just a candle like flame, but that was a great surprise to me given fog fluid is based on de-mineralised water, glycerine and glycol.
Cheers
Geoff
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Hi Geoff.
Thank you for the heads up. I was aware that you could get more smoke that your bargained for due to the residue combusting.
I will have 9 individual smoke generators, each with their own temperature sensor, they will not activate if the temperature is above a pre-set level.
I have a crude automatic way of putting out any fires / cooling the smoke generators but whilst they do get warm/hot after several consecutive "shots" I am only producing heat for a very short amount of time - approx 2 seconds during each shot , after which each smoke generator is force air cooled
I can "hard code" to vary the temperature and length of time smoke it produced, and the rate it is expelled from the gun so I have lots to play with.
The long term vision is that I will be able to amend any of these "smoke generator" parameters from the shore - this functionality builds on aspects of other projects I have already completed.
This would mean that I could produce more smoke on a windy day when it disperses all too quickly and less on a calm day
Another perhaps contraversial aspect of the "HMS RODNEY" project is "Black" funnel smoke - it's a side project - firstly to see if it's possible to produce - and secondly to evaluate what it does to the model finish and other factors
Going to be a fun winter....
C-3PO
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This photo clearly shows a 5 gun salvo:
https://www.flickr.com/photos/mayor1999/37167818735/ (https://www.flickr.com/photos/mayor1999/37167818735/)
The firing procedure was complicated by the need for all guns to be loaded together which reduced the potential rate of fire although perhaps not having much effect on the aimed rate. As with most other battleships of the time, the guns were lowered to about 3 degrees for loading and re elevated for firing, you can see this in films of the time. Loading could take place at most angles of elevation but this meant pushing the shell and charges uphill which put a strain on the hydraulics, slowing the operation. It was actually quicker to lower the gun to near horizontal for loading (and probably safer too!) and re elevate it for firing.
Lots of interesting info on the British 16 inch gun here:
http://www.navweaps.com/Weapons/WNBR_16-45_mk1.php (http://www.navweaps.com/Weapons/WNBR_16-45_mk1.php)
Colin
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Colin,
Thank you - some great info on those links - I will read more later - however the info below answers several questions I had in one hit (excuse the pun)
(https://modelboatmayhemimages.co.uk/images/2019/10/21/2019-10-21_15-02-49.jpg)
C-3PO
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Interesting that the weight of the mounting was about the same as the displacement of a contemporary destroyer!
Colin
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Big buggers those Battleship turrets!
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Although she did let rip Broadsides during the Bismarck engagement. O0
Bob
Very effective movement but the gun appears to be under the turret in the video.
You probably already know that Rodney & Nelson fired salvoes with two guns of one turret and one of another. Rarely broadsides. It is all documented somewhere!
Colin
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Although she did let rip Broadsides during the Bismarck engagement.
Yes, they were getting a bit frustrated because despite all the hits the Bismarck wouldn't blow up. Rodney only had armour piercing shells aboard having unloaded her HE outfit prior to sailing to the USA for refit so basically she was just drilling holes in and through Bismarck above the waterline as the close range rules out plunging shots. Hits that penetrated the main belt were probably deflected upwards by the turtleback armoured deck behind it.
So although Bismarck was wrecked as a fighting ship her vitals were not significantly breached, hence the subsequent arguments as to whether scuttling charges or torpedoes (or a combination of both) actually sank her.
Colin
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Read a lot recently on the did we sink her or was she scuttled, it seems the consensus including Robert Ballard, all agree that she sank due to the scuttling charges BUT all agree that if left afloat she would have sunk anyway, estimates range from an hour after cease fire to 12 hours, but all say she would have sank, so its a bit 50/50 really.
Bob
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My biggest point against the scuttling theory is who gave the order? By this stage the bridge crew were all dead and most of the communications would have been destroyed- so who would have given the order to set the scuttling charges?
Anyway as previously mentioned there were enough holes in her to make her sink anyway it was just a matter of time.
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HMS RODNEY
Having spent a fews hours today with the ever generous Mr Ron Dean from Deans Marine https://www.deansmarine.co.uk/ (https://www.deansmarine.co.uk/)
I now have a loan set of HMS Rodney plans - yipee - this will allow Peter my co-conspirator modeller to make progress with HMS Rodney - building on Ron's HMS Rodney project that we acquired a few months back from him.
With the gun smoke production, turret rotation, gun elevation, sound system all coming together this will hopefully be a great model....
What can I say - a big thank you to Ron for trusting us with his plans - and a big thank you for both his time and generosity....
Peter & I are having so much fun with this project we are tempted to buy another Deans Marine 1/96th hull and perhaps make HMS Nelson as well, whilst also considering future Dean's Marine hulls, perhaps HMS Belfast or HMS Hood or, or , or - dangerous stuff going near Dean's Marine!!!
C-3PO
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Colin I think you will find APC shells have explosive warheads, just a smaller amount to HE. HE would shatter outside of the armour belt, but would blow away lighter built accom blocks. Problem with German warships then as in the first world war was the multi box construction in the hull as their ships did not have to go on world voyages of long duration as ours so their crews mainly lived ashore in barracks. But I have a copy on my machine of the secret report sent to the USA about this engagement, 45 minutes from start to finish her when Rodney and co got her in range. I t is an interesting read tried once or twice to load it up but always stopped by being too big a file!
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Dodes,
Yes, the APC shells did have bursting charges but they were very small in relation to the weight of the shell, often less thn 5%. They were also base fused and tended to pass through lighter structures either without exploding or exploding on the far side. The HE shells, as you say, were designed to explode on contact and do massive damage to superstructure etc. and also create destructive fires.
Iain Ballantyne's excellent book on the Bismarck's last battle
https://www.amazon.co.uk/dp/B009EE9GAI/ref=dp-kindle-redirect?_encoding=UTF8&btkr=1
is packed with graphic detail on the engagement. The British tactics were to get Rodney, with the heavier broadside, in close as soon as possible and batter the Bismarck into submission which she did very well but the close range meant that sinking the ship by gunfire became difficult. In Bismarck, the armoured deck sloped down to the bottom of the side belt so AP shells penetrating the belt tended to be deflected upwards.
And of course the sheer size of Bismarck and the close internal subdivision you mention mad it difficult to sink the ship quickly.
I would be very interseted to see the file you have. Would it be possible to email it to me if I PM my address?
Colin
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Hi Colin yes no problem, if you are interested there is a free site all about Plymouth and one of its pages has official description of the various naval munitions including APC shells, plus several other bits of MoD info.
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This is a link to the file Dodes is referring to. It contains a number of obvious inaccuracies but is interesting as a historical document of the time.
https://www.history.navy.mil/content/history/nhhc/research/library/online-reading-room/title-list-alphabetically/s/sinking-of-the-bismarck/the-cruise-of-the-bismarck.html
Colin
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Having obtained a loan set of plans Peter has been checking out the scale of some of the component parts we have purchased to make sure all is in order. A few hours of confusion as he could not reconclie what he had infront of him and we began to think Shapeways 3D printed parts were scaled incorrectly.
A quick call to Ron (Deans Marine) resolved some confusion. The Deans Marine Hull is 1/96th, the plans 1/92nd but the scale matched. Now we understand that the printed plans where scaled to 1/96th from the cloth originals but the text on printed copy was as the original cloth (1/92) - obvious once you know...
(https://modelboatmayhemimages.co.uk/images/2019/10/30/walrus.jpg)
C-3PO
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That modelling is superb, hope she is at Wicksteed next year.
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I recognise the Walrus and the catapult on the turret as I’ve just bought one of each too! Lovely fittings for a fantastic model. :-))
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Definately not scratch built (!) - amazing 3d prints from Shapeways
(https://modelboatmayhemimages.co.uk/images/2019/11/05/IMG_8255.jpg)
(https://modelboatmayhemimages.co.uk/images/2019/11/05/IMG_8258.jpg)
(https://modelboatmayhemimages.co.uk/images/2019/11/05/IMG_8259.jpg)
C-3PO
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Yes, it's this sort of thing that blows traditional scratchbuilding out of the water as far as most people are concerned. Only the very top class modelmakers can come anywhere close.
Colin
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Love it.
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HMS RODNEY - moving 9 guns independantly - just 3 control wires!!
I am exploring what gun movement looks effective - a way to go yet!!
https://youtu.be/jqUp7P3BbEM (https://youtu.be/jqUp7P3BbEM)
(https://modelboatmayhemimages.co.uk/images/2019/11/09/Guns.jpg)
https://youtu.be/jqUp7P3BbEM (https://youtu.be/jqUp7P3BbEM)
C-3PO
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Most impressive C-3PO, you're definitely getting there :-)
Regards,
Ray.
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Hi Ray,
Thank you - it's certainly as fun project
I forgot to mention in my post that the guns are represented by black drinking straws in this video - on the model itself will be some expertly produced (thank you Peter Ward) custom brass barrels...and also some super smooth digital servos that are a game changer compared to the cheap and cheerful ones used on my test bed in this video
C-3PO
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Awesome looking custom brass barrels as mentioned in previous post
(https://modelboatmayhemimages.co.uk/images/2019/11/10/2019-11-10_17-04-19.jpg)
C-3PO
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More Shapeways 3D printed parts
(https://modelboatmayhemimages.co.uk/images/2019/11/11/2019-11-11_12-08-33.jpg)
C-3PO
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HMS RODNEY - development continues
https://youtu.be/c2XKgsL8wYQ
(https://modelboatmayhemimages.co.uk/images/2019/11/13/99.jpg)
https://youtu.be/c2XKgsL8wYQ
C-3PO
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Ta Dah!
The real gun barrels in the turrets - Peter ( Peter Ward) has machined these from scratch and used his black magic under the hood - they are now connected to individual elevating devices.
These will be rotating, elevating and smoking over Chrimbo
So now the superstructure awesomeness can commence
C-3PO
(https://modelboatmayhemimages.co.uk/images/2019/12/08/Dec.jpg)
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Excellent!
... Persistence is paying off O0
Regards,
Ray.
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First of the new guns smoking - yes too much!!
I will scale back the smoke at some point
https://youtu.be/iizzKuy2O0c (https://youtu.be/iizzKuy2O0c)
(https://modelboatmayhemimages.co.uk/images/2019/12/18/smoke.jpg)
https://youtu.be/iizzKuy2O0c (https://youtu.be/iizzKuy2O0c)
C-3PO
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Very Good!! :-))
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Superb !
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Pom pom guns being detailed by Peter (Peter Ward)
Whilst Peter continues his magic on the superstructure, I now have the hull back in my domain to fit out with electronic wizardry
C-3PO
(https://modelboatmayhemimages.co.uk/images/2020/01/26/IMG_8694.jpg)
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Lovely work :-)
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That paint job really highlights just how good the detail is in the 3D printed parts - looks super :-))
Regards,
Ray.
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Awesome build thread. A member of our Club is now researching for his construction of HMS Rodney in 1/72nd scale, and I am sure he will be very interested in following your progress.
Nige
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One small step... - the begining of the radio control system for HMS Rodney
and yes I know the degrees are out(!) an easy fix
https://youtu.be/9ISfzF4owk8
(https://modelboatmayhemimages.co.uk/images/2020/02/02/rcc.jpg)
https://youtu.be/9ISfzF4owk8
C-3PO
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Nice and smooth movement. :-))
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Testing main funnel smoke production - using a whisky bottle tube (850mm)
https://youtu.be/S6VtC3Un9B4 (https://youtu.be/S6VtC3Un9B4)
(https://modelboatmayhemimages.co.uk/images/2020/02/03/smoke2.jpg)
https://youtu.be/S6VtC3Un9B4 (https://youtu.be/S6VtC3Un9B4)
C-3PO
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A nice smokey flavour single malt :-)
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And the bonus is you get to enjoy the whisk first lol :-)) {-)
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First stepper strutting it's stuff...
Some formatting/button logic to be resolved but at last some progress
Radio control range from the tablet to the boat is approx 1-1.5km
https://youtu.be/Z_ksz_4wp0w (https://youtu.be/Z_ksz_4wp0w)
(https://modelboatmayhemimages.co.uk/images/2020/02/22/ipad2.jpg)
https://youtu.be/Z_ksz_4wp0w (https://youtu.be/Z_ksz_4wp0w)
Regards
C-3P0
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Very, very impressive C-3PO. You've certainly got a good skill there - love it O0 :-))
Regards,
Ray.
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HMS RODNEY
3 turrets rotating - next 9 guns elevating...
https://www.youtube.com/watch?v=8Rsj7fry6mg&fbclid=IwAR39jHGiCvcOxQIbvfHrzUZZxyPdf9zOAsruMC71FzgPdG1mkCjU8LQzEbY (https://www.youtube.com/watch?v=8Rsj7fry6mg&fbclid=IwAR39jHGiCvcOxQIbvfHrzUZZxyPdf9zOAsruMC71FzgPdG1mkCjU8LQzEbY)
C-3PO
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Very impressive! However, when it comes to elevating, how will you deal wit the extra complexity of X turret to prevent the muzzles hitting the gunhouse overhang of B turret if elevated at certain angles? This was an issue in the original vessel.
Colin
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Hi Colin,
Yes a very good point - the solution however is easy. The system knows the position of the stepper motors at any point so it's just applying some logic to stop the collision/prevent movement.
My biggest problem at the moment is getting 9 vertical sliders to appear on the control panel - they don't want to play ball in their current form so may be back to the drawing board.
I wish I was more skilled at using html/css/javascript....
C-3PO
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Very clever 8) , way over my head %%
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'applying some logic to stop the collision/prevent movement' :-)) .....you will find it easy C-3P0 O0
[/size][size=78%]J[/size][/size]ust call them non-pointing and non firing zone premissives [size=78%]
PS......the train speed is impressive
Derek
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Thanks Derek - not sure why my video uploaded to uTube in SD not HD - this makes it difficult to see the acceleration/deacceleration of the stepper motor which gives it a realistic look.
Turret X - Colin's observation prompted me to think further on the matter than my initial thoughts I had while back.
Colin kindly send a link to some information a long time ago which I have been working with - see below.
(https://modelboatmayhemimages.co.uk/images/2019/10/21/2019-10-21_15-02-49.jpg)
So my question is if Turret X is in the permissable firing/training range on one side of the ship with the guns elevated and it needs to traverse to the other side of the ship...
Do the guns need to be lowered to traverse under the back lip of Turret B or is it also permissible to leave them elevated so they traverse above Turret B?
C-3PO
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In Peter Hodges' book 'The Big Gun' the following comments are made:
Although the elevating gear was fairly straightforward in A & B turrets and had the usual style of automatic cut off at the limits of elevation and depression, X turret needed most complex safety arrangements. When trained fore and aft its muzzles lay beneath the overhang of B turret so its elevating gear had to include the means of preventing it elevating under the overhang of B, depressing into the overhang of B and training into the overhang of B at the critical elevation.
I assume ‘critical’ means the elevation needed for the range at which the ship was engaging the enemy so if the ship turned the X muzzles could hit B turret unless sufficiently elevated or depressed.
This would also need to take account of the position of B which would presumably be training on the same bearing as X so the position of the overhang and the chances of it obstructing X muzzles would depend on the position of the overhang. Maybe there is a formula in there somewhere!
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Just looking at this on face value, the following scenario could be considered
So for X turret we would consider [irrespective of Port or Stdb]
Train
0 degrees to 60 degrees of Train = Pointing Zone, Non Firing Zone - 60 degrees to 130 degrees of Train = Pointing/Firing Zone
Elevation
0 degrees to 60 degrees of Train = Non Pointing Zone, Non Firing Zone - 60 degrees to 130 degrees of Train = -3/+40 degree of elevation, Pointing/Firing Zone
PS.....
1. I am not sure what significance Note 5 is about
2. Colin, reading the word Critical, I would read it as an expression or word for a degree of elevation or train that is outside the permissibles referenced as Pointing/non Pointing or and Firing/Non Firing zones
3. We must also remember vessels of this exact vintage had no automatic ordnance trajectory compensation for any change in the vessels direction, speed, heel, roll or yaw etc
Derek
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Colin & Derek,
Thank you for info - need to read both posts a few times to see if the fog will clear.
Derek - this was the URL for the info Colin posted a while back
http://www.navweaps.com/Weapons/WNBR_16-45_mk1.php (http://www.navweaps.com/Weapons/WNBR_16-45_mk1.php)
C-3PO
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HMS Rodney
Slowly the interface to allow 9 guns to be individually elevated comes together...
(https://modelboatmayhemimages.co.uk/images/2020/02/25/Rcc1.jpg)
C-3PO
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The firing arc for X turret shown in the illustration in Burt's book is 65 degrees forward and 60 degrees aft of abeam.
Colin
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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
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Will the model have target tracking direction hold?
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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
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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
(https://modelboatmayhemimages.co.uk/images/2020/02/27/rcc2.jpg)
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C-3PO,OK, you win. I am well and truly mind boggled! Please don't stop. I kinda like it!
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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)
(https://modelboatmayhemimages.co.uk/images/2020/03/08/rcc3.jpg)
https://youtu.be/VrlplSqj2mc (https://youtu.be/VrlplSqj2mc)
Regards
C-3PO _._
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Amazing work, impressive patience!
( NB: How was air site direction passed down to the AA batteries? )
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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 :-))
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HMS RODNEY
3 turrets turning, 9 guns elevating
https://www.youtube.com/watch?v=jlO-TLJ3TJE
(https://modelboatmayhemimages.co.uk/images/2020/05/25/18.png)
https://www.youtube.com/watch?v=jlO-TLJ3TJE
C-3PO
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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. :-))
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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 (https://www.sciencedaily.com/releases/2017/06/170608145602.htm)
[well worth a moment to read as it applies to our daily life]
Derek
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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
(https://modelboatmayhemimages.co.uk/images/2019/10/21/2019-10-21_15-02-49.jpg)
C-3PO
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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
(https://modelboatmayhemimages.co.uk/images/2021/05/21/a.png)
(https://modelboatmayhemimages.co.uk/images/2021/05/21/b.png)
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It's good to see you about with some development work!
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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
(https://modelboatmayhemimages.co.uk/images/2021/06/07/2021-06-07_15-50-43.png)
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That's pretty accurate! I look forward to seeing all your developments as well as the ship to carry them on/in.
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Very impressive guys.
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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
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HMS Rodney
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Gorgeous ship model :-))
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Hms Ajax and Hms Nelson (modelboatmayhem.co.uk) (https://www.modelboatmayhem.co.uk/forum/index.php/topic,135.msg654.html#msg654)
:-))
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Looking good, how's the gunfire system going?
Cheers
Geoff