Haze Gray

I use an Anycubic Photon S

Hi CDW, yes it’s from a resin printer

So on the topic of can a 37mm Hotchkiss cannon be printed at 1/72 scale - the answer is yes - I think.... small one is actually too small (at 12mm) for 1/72, and the large one is too large (19mm) - so I've adjusted to the proportions (though it's still about 1mm longer than it technically would be at scale but) and added the shoulder brace and magazine and printing another one and hope it turns out!

Alan, what temperature do you set the bed to when printing? If your getting lifting during the print you can up the bed temp to around 60c ….. currently I set my bed at 50c but I keep the bed on after the print is done.

I've also had some good experiences with automotive primer - not sure if I would give up Gesso for it on hulls but I use primer almost exclusively on small parts (with some light sanding prior to spraying) and there it works well for me -

Hi Dan yes have that or a version of it - one think I might try is printing without the barrels and then use small pipe or rod for the barrels - but I'm going to try to print one later today.

I've heard about gesso in a spray can but it's cut with significantly more water is my understanding - so many more coats required but maybe that's not an issue.

King, I want to add that you need to resist any urge to lay on the Gesso in a thick layer - especially if you don't cut it by 20-25% water. first time I used Gesso I laid three thick layers down and thought "this is amazing - I can make all those lines disappear"...but, once dry, it took me a really, really long time just to get to the point the left over brush marks were not so visible. Gesso can be quite a durable coating, especially if it's not fully cured and if you lay it on thick it's going it could take a long time to cure. As mentioned before, test out what you want to do on a separate piece and see how it goes.

Considering how the weld lines stand proud and separate the surface of the hull into multiple sections sanding the plastic directly would be somewhat torturous (and rotary tool would remove weld lines in the blink of an eye no matter how careful you are). A very thin layer of 75% gesso/ 25%water mix could help fill in the lines somewhat and then follow up with multiple layers of primer and then sanding could be a good way to go - but I recommend you print one additional of the hull sections to test whichever method you want to pursue since you will learn a lot about what works and what doesn't.

yeah those are not going to be easy - there were 37mm Hotchkiss revolving cannons (very similar to this) and then there's the .45cal Gatling guns (which I don't think were actually mounted on the ship but on limber but can't be sure). I do have photos that show both 1lbr QF guns and the 37mm Hotchkiss revolving cannons mounted on the 4 points of the center island - and one of the drawings in the national archive calls out "gatling gun or 1lbr" in those 4 locations. "gatling gun" is is sometimes a generic term used for revolving multi-barreled guns - but I'm going to go with what I have photographic evidence of. I'm going to attempt to make the 37mm Hotchkiss revolving cannons but they are probably at the limit of what I can print so I might fall back on mounting 1lbr QF guns.....

So I looked closer at the video the way the bow breaks the water results in an extreme upward travel and a curl much further back - this really isn’t unusual for this bow shape (it’s similar to ploughing a field) if you look very closely at the bow you’ll see the waterline at the bow is actually above surface of the water but is quickly forced upwards and outwards.

Yves, You're correct - but it might be more accurate to say the ship was too light in the stern, the tips of the props were not always in the water and I probably needed about 3/4" more draft!

Pics as requested - note though that I am still a long way away from finishing - I started painting the deck and don't like the color so waiting for more appropriate paint to arrive + there's lots and lots of detail that needs to be added.

Yes, I'll post some pictures of the ship at the current state - but with nice weather over the labor day weekend and fall (rain) on the horizon I put the Maine in the water to check how it floats and get a better idea of the ballast needed - here's a video... Note: I removed the main guns and upgraded the offensive capability of the ship with sea-skimming anti-ship water bottles 😃

I figured I should start posting some updates and I have been making progress on the USS Maine - most recently I have been attending to small details like the small caliber (calibre) weapons and launches, cutters, and other deck furniture using a resin printer. here's some photos: This one is a 32ft Launch - doesn't actually go on the USS main but I have a 33ft cutter in the design stage that's pretty similar: Then there's searchlight and Driggs-Schroeder 6lb guns (yes they both pivot and swivel) unfortunately I have the searchlight rotated upside down in this shot: And I'm working on a 27' steam cutter that will go on the Maine - this print actually failed due to operator error (I didn't tighten down a knob for the build plate): will try to post some more pics later today

Hi Alan, I think this would be a good thing to consider - it uses a BL Touch probe which is what I use and it is reliable. It can be used to do two things: a) probe the corners of the bed to help you level the build plate b) "bed compensation" for the contours of the bed if it's not completly flat - or, if it's not truly level it will adjust the z-axis movement up or down to keep the distance of the nozzle from the bed uniform across the print. Technically 'bed leveling' involves the printer making adjustments automatically based on the probe measurements but I have one printer that does bed compensation and another that does automatic bed-leveling and they both work just fine. lastly, occasionally when a print of my has failed I've broken a few of the plastic probe needles but you can buy replacements for them (instead of buying a whole new probe unit) - I bought a total of 4 BL-touch probes before I figured that out I could just by the probe needle and replace it %$&#^&$)%*!!!!!!

There is an option to 3d print stanchions - but it would require something like a printer that uses ultra-violet curing resin - and you'd need to select resin that is more durable than what's typically used (most UV curable resin tends to be on the brittle side). I've not tried this but my gut tells me it's not a good option but then again I haven't tested anything.

Hi Yves, I tried a lot of different things, some were combinations (my 12 y.o. daughter helped me by applying each to test hull sections and charging me for it too!) but what seemed to work best for a single type of coating was Gesso (it’s also non toxic which is nice). Be careful though, thick layers of gesso take a long time to cure and can be a nightmare to sand down if not fully cured. A thick layer or glob of gesso can remain uncured for months and has to be peeled or cut off. Gesso applied in temperatures below 70f can take much longer to cure I typically sand down the hull by hand or with a small orbital but that’s not necessary if you apply multiple light coats and sand in between. I’ve started experimenting with some spray on options as well. I’d recommend you print out a hull section and test how the gesso works for you. Another option is to use uv curing resin - I’ve not tried that but should be viable in some circumstances depending on the resin properties.

I’ll be floating the first one pretty soon ((USS Maine). Just a photo of the painted hull attached but will have to update the thread on that build when I get back from vacation,

Small update here as I'm getting the hull ready for painting - mostly just some sanding and filling in the layer lines to get as smooth as a surface as possible - maybe a little filler in a few areas will be needed. another week or two and I should have the hull painted - one hiccup is the hull colour below the waterline - which was likely Schweinfurt green (also known as "Paris green") which was basically paint with a combination of copper and arsenic - it also have variations in the actual color but what's easily available to me at the moment is a green with a brown tinge to it, might still work for my purposes but we'll see- above the waterline I'm going to attempt to create the "lamp black" for the hull (which is a 'softer' black and not as harsh as the oxide black..so I think mixing in some brown will get the color in the right direction with some experimentation). Above the deck will be a light buff (much lighter than the typical US Navy buff... maybe more like the white star lines buff) humm colors are hard! here's a few pics of the getting the hull ready for painting - getting rid of layer lines with a combination of sanding and some readily and commercially available coating that will get sanded down makes work fairly quick. The flexible sanding pad (first image) works better then a "sanding sponge" as I can use my fingers to press into areas in a way that matches the exact shape of the proper contour. If you look at "image 2" and compare it to "image 3" that show how the how the layer lines actually are filled in (coating is translucent so in 'image 2' you can see layer lines under the surface of the coating).

Hello sms_koenig_wilhelm sorry I didn't see your message until now - there's two books that would help: ISBN 978-5-98830-060-8 (it's in russian) but if you seach the internet you can probably find an on-line copy of it ISBN-10 ‏ : ‎ 2374680231 / ISBN-13 ‏ : ‎ 978-2374680231 - this one is in French and is also helpful The drawings that I have found on the internet are pretty scant on details and there's a lot that are preliminary designs so you have to be careful and check the drawings across as many actual photographs as you can get on the Charles Martel. I Found that None of the designs actually match what was eventually built but there was enough there to get the envelop of the ship and selectively taking specific features from one drawing that were accurate and combining it with features from another drawing that has additional parts that are accurate (all along the way verifying against photographs). Also There were changes to the design as the ship was built so I doubt there were any final "as built" plans.... if you compare these two drawings to the photo you can see there's notable differences across the board

Welcome Bruce! I'm certain you'll find that MSW is great place to discuss work on projects and it's a trove of useful information. There are many great members here that are very supportive and have suggestions and advice on a wide range of topics. You're going to have a lot of fun!!

Ah yes - MICRO KRISTAL KLEAR - I haven't tried that yet but now have some on order, it's water proof when dry so should be suitable for models that go on the water.

The work you're doing on that ship really looks good yvesvidal. What are you planning to do in terms of the portholes? I think the corvette in this scale has a lot of freeboard but they could let in water in rough conditions. One thing that I haven't done enough testing on is heat susceptibility for painted 3d printed ships - the glass transition temperature (when it starts getting soft) for regular PLA is ~between 55 to 60 °C (essentially above 131f) and for PLA+ 60 °C ~140f.... I've had two bare hull sections (white PLA+) outside for 12 months and they are fine, but I'm up in the pacific northwest and the sun is not that intense - what I worry about small thin/fragile gun barrels painted black and drooping when exposed to high ambient air temp and direct sunlight. I don't think it's an issue in the northern latitudes - but I have to try out a few things and see how they do. I would suspect that hull painted black, in the back seat of a parked car on a hot day with the sun hitting it for 6 hours will exhibit some effects from the heat.

Quite a nice build and looks like a fun one at that! On joining hull sections together I've had limited success with using a solvent based plastic welding agent. I dropped one of my 3d printed ships (sections had been joined with a plastic welding agent) from a height of about 3ft on to a concrete floor and there was some separation but the weight of that ship was over 5kg empty (I use epoxy now by the way) but I doubt MEK joined hull sections of the 1/48 flower corvette will have issues (still best not to drop it!). There's a lot of things you can do with designing a boat for 3d printing, if you can imagine it, you can probably do it.