AlexM

The cylinders took a bit more than 2 hours. The cool thing about this kind of printer (called DLP printer) is, that at every step, alwas one complete layer is created by the UV display at the same time, no matter how big the part is. That means that it doesn't matter if you print just one cylinder, or in my case 20 at once. In both cases, it would take about 2 hours with my settings. Including the small support struts, the cylinders are about 1,6 cm high. According to the printig software, the main center part of the engine takes 3:45 hours with a layer hight of 0,04 mm. In reality, it might take a little bit longer, but not much. That part is a bit less than 3,5 cm high. So in just a few hours, one complete engine can be printed. Cheers Alex

Hi Gary, in fact, I haven't done any post processing concerning the surface. I just removed the bottom support structures, and washed the parts in isopropyl alcohol. Finally the parts layed a few minutes under a uv lamp to harden the parts more. The parts were printed with a layer hight of 0,04 mm. Cheers Alex

Hi Rick, thanks! My settings are: Normal exposure time (s): 16 Off time (s): 0 Bottom exposre time (s) 90 Bottom layers: 8 I haven't tried if other settings would lead to reasonable results in shorter time, but with those settings, my printed parts with this resin turned out nice so far. And for me as a hobbyist, time isn't really a critical factor. But even with those settings, the prints go pretty fast. One batch of cylinder takes just a bit more than two hours. Here is a overview with recommended settings from other Anycubic users: https://docs.google.com/spreadsheets/d/1crvzMnt_8NJXAsABinoIhcOjE8l3h7s0L82Zlh1vkL8/edit#gid=0

As Rick (SCRATCH BUILDER) said, somehow you have to outsmart gravity. Actually you can print at a certain overhanging angele, and even some vertical areas without support below. But to longer the distance, the higher the risk of a failed print. For example, if this engine would be printed as one part, the thin pushrods (0,7 mm diameter) would lay pretty flat "in the air", only connected to the main engine at both ends. I havent tried yet, but I suppose such a print wouldn't look great. You could add support-structure under those areas in the printing software, but it would be a pain to remove the support after printing. And as you said, it propably makes painting easier

Hi there, I want to share some experience with my Anycubic Photon 3d printer. I read some positive comments about the Phrozen ABS like grey resin. I gave it a try, and made a radial engine. Here, the various cylinders are sticking on the print plate, still covered with liquid resin. They all sit on support struts, which can be easily removed after printing. After cleaning in Isopropyl alcohol, that’s how it turned out. The whole diameter of the engine is about 4 cm. Looks promising for a 400 € printer Cheers Alex

I don't dare to say, but the engine cowlings were made of deodorant covers The forward parts of the cowlings, as well as the wheels, were my very first steps in 3d-printing. For the engines, there are very nice resin Bristol Pegasus/Alfa Romeo 126 RC.34 engines from Vector.

Hi Padraic, thanks. For the diamond plates there are corresponding styrene plates available: https://www.architekturbedarf.de/katalog/search?mode=check&do=riffelblech Cheers Alex

I would very much welcome a Martin turret, since this somehow prevents me to continue with my Marauder project at the moment. Apart from some photos, I found no real drawings of that turret. Did they use the same turret on the A-20G? In that case, the recently announced kit from HGW might help out Cheers Alex

Great news

I wasn't aware that cigarette ash is used for polishing, but this sounds like a good reason to start smoking as a New Year's resolution Cheers Alex

According to Wikipedia, the airfoil of the B-24 is described as Davis 22% / Davis 9.3%. As far as I understand it, the percentage means the relation between the chord line (something lile the width/length of the profile) and the maximal thicknes of the profile. That would mean that at the wing root, thickness of the profile is relatively high with 22 %, and at the wing tip relativly much thinner with 9,3 %. So the profiles at different positions of the wing are not similar in a geometrickal sense, meaning they are not just scaled to each other. The relation between width and thickness chanches at every postion of the wing, which makes it difficult to compare one certain Davis profile to a randomly chosen wing-postion of a model kit. I don't know if this drawing is accurate, but it illustrates the chanches of the relation between width and thickness of the wing: http://kativ.eu/ivohobby//Airplanes/1-48/B-24D Liberator - 1-48 Revell/Drawings/B-24J wing sections.jpg

I'm looking for the D version, so at least issue with the front turret is no problem for me (IF they don't forget to polish the moulds for the clear nose ). I suppose that the issue with the wing profile is most noticeable on the upper side. Are the lower wing halves somewhat usable in respect to the real profile? Maybe some new (for example 3d printed) upper halves that imitate the Davis profile could bring at least some improvement? Or are the wings as a whole incorrect, especially concering the position/hight where the trailing edge meets the fuselage? Alex

I don't know when the vat should be repalced. After several prints, I still see no need for an replacemet. The transparent FEP film is clamped in the vat, and basically makes the bottom of the vat. My printer already had one replacement film in the box. The FEP film gets worn after several prints and subsequently cleaning, so a little stock of film is recommended. I had to replace the first two film very soon, but now I'm more carfull at cleaning the vat, and until now, I'm doing well with the third one for some time. I found the original Anycubic films rather expensive. There are cheaper FEP films from other suppliers. You shold also buy a UV lamp the ladies use for their nail poish for postprocessing curing of the printed parts. Cheers Alex

Hi Rick, welcome to the Anycubic club The nacelles got some primer. Maybe a bit too much, but after using the scriging tool, the recesses lines are now sharp and clearly visible. The nacelle parts are glued onto the wings. This didn't went fully gape-free, so I put some thick silver respectively grey Revell enamel color at the junction between wing surface and nacelles. Once fully dried, this will be sanded. So here we are at the moment (the engine cowlings aren't glued yet, just taped):

Hi there, I though about the engine nacelles, especially the lower parts. The original (grey) parts needed cut-outs after printing for the landing gear, and some scribing at the rear for the doors, which apparently are closed on most of the period photos I'm aware of. But I HATE scribing! So much that can go wrong Therefore, I modified the existing 3d-model, so they now already have the cut-out, and some recessed lines for the rear doors. The new printed (green) parts will benefit from some sanding, for sure, but the recessed lines are looking promising. Cheers Alex