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Author Topic: HMS Coventry D118 Type 42 destroyer - 1/96 3D printed  (Read 1525 times)

DamienB

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Re: HMS Coventry D118 Type 42 destroyer - 1/96 3D printed
« Reply #25 on: November 29, 2020, 09:57:13 pm »

Tilting is about reducing surface area on each layer and therefore the force needed to peel off the exposure plate, and move through the liquid resin. Nothing 'drips off' during the process itself, as it's all happening within the liquid medium. Whether it drips off at the end is irrelevant as I run it through a cleaning solution of IPA to clean any uncured resin off.
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DamienB

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Re: HMS Coventry D118 Type 42 destroyer - 1/96 3D printed
« Reply #26 on: December 01, 2020, 05:37:35 pm »


Aft hangar block external view, with life raft shelves glued on. One genius aspect of this UV curing resin is you can use it as glue - just apply a thin layer to the surface and point a UV flashlight at it. It hardens incredibly quickly and forms a really solid bond. Far, far better than superglue. There are various details missing from the hangar at this point - approach lights, landing aids, a big cabinet on the aft bulkhead - all to come later.
If you look very closely you can see the fine stepped lines on the angled surface of the life raft shelves. As these will be obscured by the liferafts once fitted I'm not bothered about sanding them smooth. The side of the hangar has more widely spaced lines, which I have made some effort to sand off.


This is the area of superstructure forward of the actual hangar. Annoyingly, this was too big to print it one go too so I split it in two (you can see the join line along the top near the ladder). The obvious choice here for build plate surface was the roof itself, which avoids any shelves collecting resin elsewhere. So I cut off the little bit sticking up and printed that separately too. Also you'll see an open ventilator hatch, I seperated that out before printing as it otherwise gets cut in two by the roof line.


Another view, showing some reinforcement walls to keep things stiff. In the end I don't think these were actually necessary and were I to print this block again I'd try without them.

Printed item, primed and glued to the aft section. I've clipped off the reinforcement bits to save weight.

Some assorted gubbins for the upper hangar deck. Lockers, cabinets etc. plus the blast shield and control kit for the Corvus chaff launchers.


Took two attempts to print the Corvus shields, as they needed more of a floor to work properly, but they came out OK second time. Rough placement of various bits to see how far I'd got - this was actually taken before the 'glued together' shot earlier in this post hence the missing life raft shelves.
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derekwarner

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Re: HMS Coventry D118 Type 42 destroyer - 1/96 3D printed
« Reply #27 on: December 01, 2020, 06:14:41 pm »

Have been following on Damien.......there is absolutely no reason why 3D printing can be used for larger structures, I just never considered this aspect


So based upon CAD and correct input, the accuracy of scale detail output is astonishingly sharp & clear  :-))


Derek
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Derek Warner

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DamienB

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Re: HMS Coventry D118 Type 42 destroyer - 1/96 3D printed
« Reply #28 on: December 01, 2020, 06:59:03 pm »

I'm so impressed by the printer output. I've found myself designing bolts that are sticking out 0.2mm from a surface, then kicking myself for wasting time, then printing it and finding you can see them!
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RST

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Re: HMS Coventry D118 Type 42 destroyer - 1/96 3D printed
« Reply #29 on: December 01, 2020, 08:41:52 pm »

How do you find the fumes and clean-up. I' >:-o m itching to take advantage of discounts and get a printer / curer and clean-up combo, but there is no way I can deal with quantities of IPA -will need to be the water based resin.  Where do you keep your clean-up solution so the light gets to it to cure washed off resin? I'm struggling with that concept also but your work is really tempting.
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DamienB

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Re: HMS Coventry D118 Type 42 destroyer - 1/96 3D printed
« Reply #30 on: December 01, 2020, 09:49:42 pm »

The Mars Pro I use was smelly first time I used it but not since (it has a gasket round the cover, and a filter on the fan). For cleaning, I initially used IPA and a toothbrush and then a little turntable and a UV lamp to post-cure. Messy, time consuming. Chucked a hundred quid at the Elegoo Wash & Cure machine. Fill the bucket with IPA, a few buttons presses - print is basically clean. Remove item from build plate, remove supports, dab any remaining IPA dry, put back in machine, press a few buttons - cured. Game changer - so much less hassle. Every now and again the IPA needs to be sat in a window sill to cure out the suspended resin bits (or use the cure cycle in the wash & cure machine!), then pour it through a coffee filter to clear it up a bit more and re-use.
The water washable resin suffers from cracking, and while you are using water for cleanup, you can't pour that water down the drain as it still contains resin which is bad for the environment, you still can't handle it with bare hands, so basically the only plus is you don't have to chuck 30 a year or so at buying IPA. I don't particularly mind the smell of IPA, and the container is only open briefly so health hazards low. I use blue nitrile gloves for all handling of the build plate and item up to curing stage, if you're careful you can reuse them several times before they get sticky.
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RST

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Re: HMS Coventry D118 Type 42 destroyer - 1/96 3D printed
« Reply #31 on: December 01, 2020, 10:04:08 pm »

Thanks for your reply. Kind of confirms what I was thinking with resin printing. Great prints but too much clean-up and disposal I can deal with (also I'm in a flat and have enough modelling incendiaries stored as is). I hadn't found much feedback on the water based resin so that's good to know. I have more than enough PPE but the clean-up is prohibitive, I'll have to stick with my current printers.  Thanks for posting back.
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DamienB

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Re: HMS Coventry D118 Type 42 destroyer - 1/96 3D printed
« Reply #32 on: December 03, 2020, 01:01:44 am »

Modelling incendiaries  {-)
Right, light relief time. Funny I always think doing a small bit will be less work than the big chunks. They never are.



Mk.32 Shipborne Torpedo Weapon System (STWS) or the triple torpedo tube as the Septics call it. Great bit of bolt-on kit dating from 1960 with a rotating mount and 3 torpedoes ejected by a compressed air system (the hemispherical end) after the end cap (left) hinges up out of the way. The derrick to the right is used for loading torpedoes into the tubes.On later ships these were removed to make space and weight capacity for other equipment such as more guns - the ship retained torpedo capability via the Ship's Flight Lynx.

STWS fresh from washing after printing. If you look closely you'll see a flat disc under each one - this is where the mounting failed to print correctly.


After post cure and removal of supports. I ended up making separate parts for the mountings as they didn't print correctly for some reason. Look at that detail - I didn't think the wiring on the junction box would come out for instance!
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warspite

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Re: HMS Coventry D118 Type 42 destroyer - 1/96 3D printed
« Reply #33 on: December 03, 2020, 10:22:31 am »

Why 4 ?


Would it not have been easier to split it up into 'Airfix / Matchbox' sub assemblies ?


Otherwise brilliant  :-))
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Operational - 1/72 LCMIII, 1/180 Sovereign, HMS Victory to be sailed
Non Operational - 1/72 Corvette, 1/72 E-Boat, 1/72 vosper mtb
incomplete, tug, cardboard castle class convert

DamienB

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Re: HMS Coventry D118 Type 42 destroyer - 1/96 3D printed
« Reply #34 on: December 03, 2020, 12:07:16 pm »

For a lot of the smaller items I'm printing multiple copies purely so I have spares in case of minor failures, or trying different orientations for comparison. I'm just being lazy trying to model things to be the minimum number of parts. Almost everything being the same colour grey helps :)
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DamienB

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Re: HMS Coventry D118 Type 42 destroyer - 1/96 3D printed
« Reply #35 on: December 06, 2020, 01:17:41 pm »


Now, going back to the central superstructure. Again on comparison with scale plans, something was seriously out. It looks like the entire section is too long, with the errors spread over several places. The lack of detail and the cross passageway made the decision to rebuild the section under the funnel easy enough. However, choosing the orientation to print it was trickier - flat deck is the obvious build plate area, but makes the part too wide to print in one go. Also too long, of course. So this part is actually split into 4 bits for printing.


Resulting bits, glued together, and placed on top of the existing model structure to demonstrate how far out the woodwork is. The big empty space gives me more room to possibly put a smoke generator in the funnel... hmmm.... 😃  Any recommendations for an inexpensive non-polluting smokey thing?



So, the funnel. As I mentioned earlier I had a quite nice funnel replacement already. Big chunky bit of resin - 90 grams of it. Dimensionally pretty accurate but a little lacking in detail perhaps. And it had two big rectangular depressions on top that aren't there on photos of early type 42s. So, sod it, designed that too 😃 As I've been doing with other bits, I'm going with ladders and railings embedded on the surface rather than being separate items. This is because it'll save me time and fiddling, and hopefully be more robust when it comes to handling the model.



Completed funnel test fit - spot on. The holes in the side of the funnel are for later use to put in some aerial spreader poles, resin wouldn't be strong enough for those so I'll use brass rod. I have used resin for the bracing to the side of the main mast as you can see on the far right - that's under no load so while it's still delicate I might get away with it, or I might replace with brass too. The completed funnel is 64 grams, so a nice little weight saving on the Sirmar item too. This is a wide angle shot so the forward side of the funnel is distorted looking - it does correctly slope back a bit in reality.
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