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[JohnG]

Hi,

I'm building HMS Broke - a WW1 flotilla leader.

She was built by JS White in Cowes for the Chilean navy, was requisitioned in 1914, was at Jutland, and then part of the Dover Patrol including an action in april 2017. 

There's a strong family connection which has motivated the build.   

it's my first ship model. i'm 3d printing the parts from plans and a few pictures.

[JohnG]

the design was done in the 'blender' program - working from a digital copy of the original plans.


the plans are held at the national maritime museum in greenwich - who are very helpful. a real pleasure to be able to visit and handle the originals..

[JohnG]

the hull was printed in 7 sections

[JohnG]

the material is ABS - which so glued together with plastic pipe cement.

[raflaunches]

Hi John G


Fantastic subject and definitely good use of modern technology. I have a liking for vessels of this era. I’ll be watching your build with great interest.


Oh, and welcome to the forum 

[JohnG]

thanks Nick - encouragement highly appreciated!


here's the process i followed for the modelling


https://modelshipworld.com/topic/20027-hull-modeling-with-blender/


definitely a mental workout to learn enough of the 'blender' program - and still learning..


i used offcuts from failed prints (there were a few..) for the joints

[JohnG]

adding motors and props. 


i'm going for the original configuration of 3 motors - hope it's not too ambitious....


helpful advice from simon at www.prop-shop.co.uk

[JohnG]

final joint (with hand drill as an unconventional weight to hold it in place)


and float test in bath - thankfully successful - kept the water low in case...

[JohnG]

funnels and part built bridge


plus ventilator cowls - i'm learning that the printer is surprisingly capable with more delicate items .. though mostly not first time!

[JohnG]

torpedo launchers/directors and qf guns plus mountings


I found the original 'description of armament' by the makers 'sir w.g.armstrong, whitworth and co ltd' at the nmm in greenwich.


Broke had 4 inch 40 calibre qf guns originally. 


it's a challenge to 3d model the complex guns into something the printer can handle... i had to add blocks at the end of the barrel to stop the plastic bending upwards during the print.


one of the few detailed pics i've found is this one of the foredeck


https://www.iwm.org.uk/collections/item/object/205252712


incredibly  useful to compare with the model...

[JohnG]

decks and fittings all placed rather than glued.


and a link to a pic of Broke in dover harbour


https://www.iwm.org.uk/collections/item/object/205213676



this is as far as i've got to date.

[SailorGreg]

Hi John, welcome to the mayhem!  That's a fascinating build.  I have read of other 3D printed models but yours is the first I have seen that really shows how it is done (including the Blender tutorial).

Incidentally, I assume in the picture below that this is not the final configuration of the prop shafts?  The propellers should be hard up against the A-brackets to do away with that long length of unsupported shaft, to make some room for the rudders and to prevent the thrust being taken by the electric motors.  But I guess you know all that, sorry for the sucking eggs lesson!
Do keep the pictures coming.

Greg

[JohnG]

Thanks Greg


your encouragement is most welcome.


yes the pic you spotted was aligning the A brackets.


below shows final position of shafts  - and intermediate one with clearance of rudder.


rudder is virtually scale size - i'm relying on being able to reverse one prop for turning if needed rather than oversizing the rudder - it worked in real life so fingers crossed...


and "obvious" comments very much  welcome - i'm new to this so will definitely miss things.

[SailorGreg]

If you are thinking or using the props to aid steering, you might want to consider a mixer like Action Electronics P40E which will slow, stop or reverse (you choose which) the inside propeller in a turn.

Greg

[JohnG]

that's exactly the functionality - and the one you linked to looks promising. thanks!


my current plan is to do the same using a raspberry pi -  potentially controlled via bluetooth to a phone. i've only just had the first motor controller arrive, so have some work to do to test the concept/components.  there's an app called bluedot that looks promising - it works on land...


https://www.youtube.com/watch?v=eW9oEPySF58


and i've used bluetooth over a similar distance for something else.


if it works then there's less hardware and more its flexible - if not then i'll revert to conventional rc with a mixer...

[Geoff]

Really interesting and keep up the excellent work, and the pictures!


Cheers


Geoff

[furball]

Very nice. May I ask what slicer you’re using, or does Blender produce the gcode directly?


I’ve got an Ender 5, and it’s interesting to see what they can do.


Lance

[JohnG]

thanks Geoff -  i was hesitant to start posting - so encouragement much appreciated!

and Lance - i produce a stl file from the model created in  Blender (www.blender.org) , and then use Cura (   https://ultimaker.com/software/ultimaker-cura ) as the slicer to produce the gcode (=instructions for the printer).

for interest the pic is a screen grab from Cura of the gun shield  - (top view cut through half way up , i printed it inverted ).  you can see the individual lines the print head will follow - magical!

the printer is a pretty standard Creality Ender 3.   i use Octoprint (www.octoprint.org) to run the printer on a raspberry pi.   print times can be pretty long - over a day for some of the hull sections- octoprint means i can check it remotely.

Blender, Cura and Octoprint are all excellent (and free) pieces of software. getting to grips with Blender was the the biggest challenge. i know there are other packages out there - it was the link to 'how to model a hull ' that started me working with blender.

[RST]

I use cura but it seems a bit unstable.  I NEVER update to latest after last time -because frankly it never works afterwards and screws up everythng.  Best thing for me and cura is still try to remain 1 or 2 revisions older:  let the most recent bugs be reported and fixed by someone else.

[ballastanksian]

Welcome to the forum John! Your hull assembly looks great and is an excellent way of pushing your skills and learning to the limit  Can you print wider? I ask because you could print larger hulls in smaller segments.


Keep up the good work 

[JohnG]

Hi RST,
i'm still at the stage of marveling at what cura can do. there are lots of little frustrations along the way - but mostly with moving from the blender model to the cura slicing: persuading the appropriate parts to be 'solid' and not others doesn't always work out first time. i'm sure it's partly experience/learning - and maybe partly that blender is largely a 3d graphics package at least as much as for cad. i've not had major issues with cura - so far. (i did experiment with craftware      https://craftbot.com/craftware/   but it didn't solve the issue i was grappling with, and to be honest learning one program at a time is enough..) 

and ballastanksian  thanks for the kind comment: i actually printed the sections vertically (see the pic in reply 2).  here's why:
one of the challenges is 'support' - the filament can't 'bridge' too far across a horizontal gap, so the slicer can produce temporary supports to allow bridging. but i found they tended to be temperamental for the hull sections - you can see the supports but also the 'spaghetti' where non- crucial ones were failing.   printing vertically drastically reduces the need for support and gives a flat plane to sit more securely on the printer bed-.... however it does bring other challenges. because it's printing hot filament onto cooler model parts, it builds up some stresses in the part, and also can deform a little: you can see cracks in one section in reply 3. also the sections tended to spread wider in the middle - so i added cross ties to bring in the sides slightly. the pic shows both cross ties, and the extra beam added half way up the side of the hull to help with layer adhesion.


(the choice of ABS as a material may have made the printing a little more challenging too - but that's a different topic.)   


to answer your main question - with printing vertically it's the vertical size  of the printer that becomes the limiting factor for bigger segments... i know there are adaptions of the ender 3 that simply add a longer vertical bar etc to give greater build height  (  https://www.youtube.com/watch?v=Qi6Qo-SY2pk&t=659s):  the challenges would then be around the adhesion, deformation during printing etc that i've mentioned.

[JohnG]

well, yesterday was a good day:


 - cut the prop shafts to length
- test fitted the rudder, and tested the servo (using a conventional rc )
(interesting that the clearance between rudder and middle prop is rather less than in the plan- but still adequate - fortunately!).


- hooked up the raspberry pi (pic 2533 shows lipo's, voltage reducer, l298n motor controller, and pi)
- test ran the 3 motors in turn controlled by the pi
-  tested using the pi to control the servo.
- and tested the bluedot software ( https://bluedot.readthedocs.io/en/latest/gettingstarted.html ) to link to the pi


very pleased that all the bits worked - particularly that the motors and servo seem to do the job - they're all relatively cheap ones from ebay. and that the plan for 'control by pi' looks promising.


there will be the challenge of knitting the bits of software into the functionality of a mixer (btw the link from sailorgreg was useful for the link for functionality - thanks!). i'm hoping i can persuade a friend to do that bit - his programming is much more elegant than mine!


and finally - my new airbrush set arrived - so time to start planning the painting.. that's another new skill.  and of course the '50 shades of grey' question - what colour was a ww1 warship... ? i have some clues..

[ballastanksian]

The key is that as the war progressed the grey got lighter with some official standards. There is a thread on here that discusses it in some detail even including recipes for greys and modern colour matches.


You can deepen the debate further by adding the Razzle dazzle schemes that many WW1 warships and merchantmen acquired from time to time as the situation demanded. I read it through but didn't think anyone would be interested and forgot the name of the thread. RAF Launches started a thread on Dazzle schemes for HMS Kent.


Your ABS is not far off the colour warships would have been painted around 1905-1916 being a dark grey. Then uperworks on smaller ships began to be painted lighter, and by 1918, most ships were painted in lighter greys. White Ensign/Sovereign hobbies (?) have extensive knowledge and colours available for most eras.

[Rob47]

Action 2017 wow 
But its looking great though


Bob

Hi,

I'm building HMS Broke - a WW1 flotilla leader.

She was built by JS White in Cowes for the Chilean navy, was requisitioned in 1914, was at Jutland, and then part of the Dover Patrol including an action in april 2017. 

There's a strong family connection which has motivated the build.   

it's my first ship model. i'm 3d printing the parts from plans and a few pictures.

[JohnG]

thanks Bob!!   April 1917 of course.. battle of the dover strait 21 april 1917 to be precise.   
(if only there was an edit function...)

and thanks  ballastanksian. i'd seen similar info as a thread here:   http://www.shipmodels.info/mws_forum/viewtopic.php?f=69&t=154630  - but will look for the one on mayhem.