Topic: SMS G42 (1915) V25 class torpedo boat. 3d print/scratch build. 1:96 scale (Read 3986 times)

JohnG · « **on:** July 26, 2022, 10:33:07 am »

I’m starting the cad modelling for a new 3d print and build.

It follows on from my HMS Broke build.
https://www.modelboatmayhem.co.uk/forum/index.php?topic=64903.0

SMS G42 was one of the ships involved with HMS Broke in the Battle of the Dover Strait - so it continues the (rather niche) theme..

She was built by Germaniawerft in Kiel in 1915. https://en.wikipedia.org/wiki/SMS_G42
There’s a rather fine builders model of sister ship G37 an the National Maritime Museum in Greenwich, which is probably going to be my best source of detail. I plan to go see the model and take plenty of photos.
https://www.rmg.co.uk/collections/objects/rmgc-object-67387

Here’s a couple of early screenshots of the cad hull modelling – with the pic of the nmm model mounted behind that i worked from. I'm using the 'blender' 3d package again - much quicker second time round.
( I just realised I’ve flipped the photo, and then modelled it – so the non symmetric part of the bridge is a mirror image of what it should be – oops – need to flip it back! )

I also found a few different plans of other ww1 german torpedo boats I’ve waiting for delivery of a plan of S49 from the Polish Modelarstwo Okretowe (thanks to ballastanksian for the suggestion). These other plans give some help to complement the nmm model, even if not exactly the same layout. There’s also a good 3d printed model of a v25 here https://scalemodelguy.com/index.php/sms-v25/ but the layout is significantly different.

Info on the G37-G42 ships is pretty sparse. I eventually took the hull cross section/profiles from a V170 plan. http://www.dreadnoughtproject.org/plans/SM_V170-177_1918/

tonyH · « **Reply #1 on:** July 26, 2022, 10:41:54 am »

I assume that S23 was similar to S29, so these may help if you end up in that direction. http://dreadnoughtproject.org/plans/SM_S23_1913/

JohnG · « **Reply #2 on:** July 26, 2022, 10:59:31 am »

thanks Tony,

yes i'd spotted that one - again a different layout esp around the bridge/1st funnel.

curious that one of the S23 drawings shows a sail hoisted on the aft mast - i had no idea the masts might be used for sails on these ships. i wonder if it was to steady the roll of the ship rather than propulsion?

tonyH · « **Reply #3 on:** July 26, 2022, 03:24:38 pm »

Hi John,
The sail facility seems to have been common on TBs and TB destroyers of the period. Some years ago I built this one (See:Pointy Thing) which carried a jib on a "just in case" basis. Witnesses from this esteemed forum will tell you that she steered like a dog due to the screws being aft of the rudders but she did move forward quite well under sail alone. http://dreadnoughtproject.org/French%20Warship%20Plans/Arquebuse_1902/
Tony

ballastanksian · « **Reply #4 on:** September 06, 2022, 11:26:31 pm »

Great news John! Your design is looking good already. I am glad the info I remembered from a while back is of some use. The magazines are excellent.

JohnG · « **Reply #5 on:** March 20, 2023, 10:47:04 pm »

well it's been a while, but the model is finally making progress.

i visited the NMM at greenwich - saw and photographed their model of G37 which was on display. a fine model in a larger scale, so lots of detail. This becomes my main source.

i've put a lot more detail into the 3d model (And found a way to display with slightly funky colours)

JohnG · « **Reply #6 on:** March 20, 2023, 10:48:47 pm »

the process is as described for my hms broke build - model in 'blender' package, and print on home 3d printer

JohnG · « **Reply #7 on:** March 20, 2023, 11:04:47 pm »

Printing - getting over the separation.....

i've nearly done the main print of the hull. 1:96 scale as before.

I'm printing in PETG instead of ABS - with the HMS Broke model it was a major problem getting adhesion between the filament layers in the prints.
(i ended up gluing some extra abs on the inside of the model for strength - using it rather like glass mat for strength.)

Anyway, this time, after reading round, a few false starts, and a new print head on my Ender 3, i'm finally getting something robust with PETG filament.

This is the bow section - comes out v shiny, and with a definitely rough surface from the filament.
(PETG is heat and water resistant enough, but can't use the acetone smoothing that works with the ABS)

JohnG · « **Reply #8 on:** March 20, 2023, 11:09:37 pm »

After sanding and a skim of humbrol filler, the surface is pretty good. i'll find our more when i put primer on.

The hull is in 5 sections. 4 of the 5 are printed and the 5th on the printer as i type - a 13 hour print.

meantime i'm prepping and jointing the ones done so far.

ScottW · « **Reply #9 on:** March 20, 2023, 11:13:21 pm »

It has been long enough that I don't remember whether this model is intended for static display or in-water operation.Question is, what effect on an operational model would that rough surface from printing have?

JohnG · « **Reply #10 on:** March 20, 2023, 11:14:23 pm »

A question on colours....

now a question - what colour should she be - german channel operations in 1917?

the builders model at the NMM is black above the waterline and grey below. Looks quite impressive, and easy to model!

[size=0px]https://www.rmg.co.uk/collections/objects/rmgc-object-67387[/size][/color]

does anyone have any other info/views??

JohnG · « **Reply #11 on:** March 20, 2023, 11:22:41 pm »

Quote from: ScottW on March 20, 2023, 11:13:21 pm

It has been long enough that I don't remember whether this model is intended for static display or in-water operation.Question is, what effect on an operational model would that rough surface from printing have?

Hi Scott,
She's intended to go on water, RC controlled. the rough surface is pretty much removed by sand/fill/sand - i wouldn't have been happy with it direct off the printer.
(in contrast the layer separation would have had quite a serious effect on in water operation.....

)

i'm no expert at 3d printing - just do enough to get the result i want. it does seem the PETG is slightly rougher that the abs was using the same process.

JohnG · « **Reply #12 on:** March 22, 2023, 03:44:27 pm »

hull now in one piece. shouldn't take too long (famous last words) to smooth the joints and get a coat of primer on.
meantime rudder ordered along with some brass rods for masts etc. progress!

JohnG · « **Reply #13 on:** March 24, 2023, 11:43:29 pm »

well, i have a hull! all 5 pieces joined, smoothed, and a quick coat of primer to show how the finish looks. some touching up to do, but overall not so bad..
(also shown for scale against my model of hms broke. both 1/96 and the g42 hull is around 20cm shorter. )

must say i quite like the black (as per builders model). though looking online at ww1 era photos, they do tend to look more grey than black.
I'd value any comments - colours for ww1 channel fleet?

here are a few pics i found so far. with b&w images it's near impossible to judge the colour tone..

https://www.alamy.com/german-torpedo-boats-in-flanders-1916-image68839146.html?imageid=B23C9669-C3C0-4708-AD06-7433DF05A5F2&p=291611&pn=1&searchId=7a505538b1d7a6a95b717d269a3705c5&searchtype=0

https://www.alamy.com/sms-g-135-image397133913.html?imageid=CBB35B49-96C9-46CE-BA7D-23DE17D61560&p=1392328&pn=1&searchId=5d7f1bea9011451b8e4d4642914f07c3&searchtype=0

https://www.alamy.com/german-torpedo-boats-1916-image68839148.html?imageid=5DDE4769-1384-4C65-949F-3A0510BE6A2D&p=291611&pn=1&searchId=5c40a9454885ffbda682400f9c167b47&searchtype=0

raflaunches · « **Reply #14 on:** March 25, 2023, 08:29:36 am »

Hi John

Great to see this back on the stocks. After seeing Broke last year I am looking forward to seeing her German counterpart. You can see the differences in design between the two navies. I was shocked after reading several books on the subject of destroyers of how many German TBDs and destroyers were lost in WW1 compared to the British vessels.
Keep up the amazing work

JohnG · « **Reply #15 on:** March 25, 2023, 07:36:21 pm »

thanks nick - encouragement appreciated. i've pencilled in the wicksteed weekend - though there's no way i'll have this one finished by then.

ballastanksian · « **Reply #16 on:** March 27, 2023, 09:52:24 pm »

I think that as the war progressed warships got somewhat lighter, but many vessels were much darker than you would find in WW2.

Go with what you find as a consensus John. I painted my destroyer with the dark grey available from Halfords in a rattle can but you may find it worth mixing your own from other sources such as bulk buy of Revell or Humbrol tinlets, or from Sovereign, who will probably have shades based on research.

JohnG · « **Reply #17 on:** March 30, 2023, 12:50:35 am »

thanks for the comment ian.

based on a couple of references that google turned up, eg

http://www.gwpda.org/naval/s1200000.htm#:~:text=Torpedo%20boats%20were%20painted%20black,cases%20styles%20of%20disruptive%20camouflage.

plus the fact that the builders model at nmm greenwich is black, i think i'll go with that. most likely vallejo as i've used their colour before with the airbrush.

in other news:

- i've been treated to a resin printer - v pleased with the initial results - far better definition as hoped for. first out are the main sections of the bridge. i wouldn't have thought of trying to print the port and starboard lanterns with the other printer. here they are great.

the snag is of course that now it's possible to include more detail, which means take more time to do the cad work... ah well

ballastanksian · « **Reply #18 on:** March 30, 2023, 10:43:04 pm »

I bought a couple printers last year (one of each) to try out. I haven't used them yet as I have not yet had room but reckon they do have potential. The resin printer has the benefit indeed of giving you smoother surfaces especially if you angle the print to minimise stepping.

The support work done in the slicer program looks to be pivotal to getting a good pprint.

JohnG · « **Reply #19 on:** April 11, 2023, 05:26:37 pm »

making a little progress - the black is looking good - i'll keep grey below the waterline as per the original shipyard's builders model.

the main bridge, funnels and air scoops placed on the (not yet painted) deck. starts to look menacing - as i rather think the original would have done!

annoyingly i hadn't gently sanded enough the edge to the first coat of grey despite trying to airbrush a soft edge to the grey below the waterline - the masking tape line shows - so will have to go back over with wet and dry and then respray.

yes Ian, adjusting the slicer is a key part of the printing - both filament and resin (and of course different progs to run for each). Particularly looking at the print layer by layer (not as slow as it sounds) to see what will actually print saves a few wasted prints too.
on balance though it's the cad prog that's the really complex bit i'm finding. i work with blender for the cad primarily because that's where i found the hull modelling process when i started. i'm managing to add eg steps up the funnels and metalwork around them too with the resin print - will be interesting to see how it looks once picked out in a metallic paint.

ballastanksian · « **Reply #20 on:** April 11, 2023, 08:51:40 pm »

Yup, them printers are not plug and play. The destroyer looks great so far John!

JohnG · « **Reply #21 on:** May 25, 2023, 11:43:10 pm »

What a great motivator Mayhem at Wicksteed is:

Decided if i was coming to the weekend, i really needed to be able to bring something - especially as it was Ian (previous commenter) who gave me the 'what are you going to build next?' nudge last year...

so lots of work done this past week:

- Main deck fittings printed, painted, placed (not yet permanently fixed)

- Props/motors/electrics fitted/tested

- Bath test - fixed leaks (oops) , and balanced

so ready for wicksteed!!

The only question is 'do i dare put her in the water - when i haven't tuned the handling at all ?'....... (especially given previous history with earlier model that didn't quite make it back to shore when insufficiently tested.... ) .. Watch this space.....

anyway car just about packed - off in the morning. yippee!

ballastanksian · « **Reply #22 on:** June 13, 2023, 03:59:12 pm »

There is a fine flotilla of escort vessels building up at Wicksteed now, what with Tony's German Torpedo boat and British Destroyer, and now your pair!

We just need a battle ship!

Geoff · « **Reply #23 on:** June 14, 2023, 11:47:52 am »

Ha, now that I can provide, Iron Duke or Invincible!!

Cheers

Geoff

raflaunches · « **Reply #24 on:** June 14, 2023, 12:20:54 pm »

Hopefully I’ll have an operational large light cruiser next year too

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Author Topic: SMS G42 (1915) V25 class torpedo boat. 3d print/scratch build. 1:96 scale (Read 3986 times)