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ICMF

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  1. Yay! My Saturn 2 has arrived! Upgrading from both a Phrozen Mighty (for the bigger size) and OG Photon (for the higher res) I haven't been able to run it yet, but resin printers are kind of commodity products at this point, so barring any major design flaws, it should be fine. A few thoughts for those who are interested: Like: Power switch is on the front of the machine. Nice for multi-printer setups and just generally more ergonomic. Lid "pre-drilled" with hole for vent fan. There's a moulded in hole (with screwed on cover) for a ~70mm PC fan to help vent the machine. Those that want to add extra ventilation won't have to mutilate the lid. Vat has max fill indicated. Simple but handy touch. Vat has handles. Pretty much a requirement at this size. Vat has feet, protecting the FEP when you set it on a workbench. Simple solution with four thicker cap-head screws, but it'll save scratches/damage/punctures. Build plate is a positive fit. Handy if you have to remove and reinstall the plate mid-print for some reason. Plug in charcoal filter. The printer has a USB socket on top *strictly* for plugging in the included filter. Easier than using one of the battery operated filters, but DO NOT PLUG IN OTHER USB ACCESSORIES. No-Like The vat screws are too long. They thread about 1/2" into the printer, so they'll be annoying to screw/unscrew. The power button is a momentary switch. It takes about a second for the screen to light up, so there's a bit of "did I press it hard enough or not" uncertainty when you turn it on. Tape around screen. Elegoo have applied a tape/gasket to seal the screen from resin leaks, but the cutout is actually smaller than the build plate, which makes levelling... confusing? Narrower tape or a thinner build plate (it's larger than the screen) would help. Meh. (not a fan, but not a big deal) The design. It's a little Transformers, IMO. I'd be good without the angles. USB socket is at the rear left. I'd much prefer it to be at the front, but it's easy to fix with an extension cable. Pouring lip on the vat is in the top left corner (or else max fill line is in the wrong location). Bit of a nit, but with the fill line visible, I'll have to rotate the vat to pour resin out of the spout; with the spout in my preferred location, the max fill is at the front of the printer, and less visible. Ball jointed build plate. Not a huge fan of Elegoo's levelling system, and with a plate this large (10"), it would really benefit from four point levelling. Solid feet. These are moulded into the chassis. I'd prefer to have adjustable feet, so I can level the printer itself. Plastic chassis. I honestly don't care - it's sturdy enough for a resin printer - but some people will complain.
  2. Bah. You're never too old. (but yeah, I get it. build whatever makes you happy.)
  3. Well I can answer the spool part, at least: it's 'detail 1' in the scale drawings (the cylinder under the upper wing), so... about 21 x 1050 mm. Be proud. CAD offers the advantage that size doesn't matter - I can zoom in and add microscopic details as easily as anything else. That's not true of scratchbuilding - sway braces are a pain to detail! I won't be selling the files, but if there's interest, I will make the kit available. Being an experienced scratchbuilder, you should have a big leg up in learning CAD, if you ever choose to do so. I think one of the biggest hurdles is being able to break complex objects down into simple shapes - seeing a busy cockpit as a series of circles and squares, for instance - so if you've got a handle on that, you're a long ways towards understanding how to think about designing parts in CAD. After that, it's "just" learning how the software works. Not saying it will be easy, but certainly easier than starting from zero.
  4. I'll put you out of your misery: it was fly by wire. https://en.wikipedia.org/wiki/Siemens_torpedo_glider
  5. Small update. Since the plan (at the moment) is to finish it as a late-career test ship, I needed something cool to dangle underneath. That means SSW torpedo gliders - one of the first "precision" air to ground munitions. Scale drawings were imported into Solidworks, then scaled and traced (the measurements are very helpful here): And the CAD model completed. Same process as the Zeppelin - various bits were extruded, revolved, cut, shelled and filleted to shape. I can do a detailed breakdown again, but you probably get the gist: Designed in 1/144, currently printing in both 1/144 and 1/72. And for anyone wondering, it's about 50mm/2" long in 1/144.
  6. Glad you're enjoying it. That was a big part of my goal in the thread - to show what's involved in designing and printing a kit. Lots of people talk about and are interested in 3D printing, so I thought a thread that (hopefully) explained the nuts and bolts would be useful. Oh, and look forward no more! Success! (mostly). All the parts turned out well. Had a bit of trouble with the first cm or so of the prints, so they're a little wobbly - not sure why, but it might have been due to mixing resins in the vat (had a bit of older, grey in there, topped it up with a bunch of clear). Ah well, it's certainly fine for a test run, and bodes well for any future 1/350 prints of the model I might want to do. (hint, hint :D) Close up on the tailplanes, showing the nice, subtle ribbing. It's a little more opaque than I'd like - I used a clear resin to play with the translucency if/when I get around to painting it. Even the fine door framing rendered well. Not as happy with the gondolas. They're a bit meh, and I'd reprint them if I wanted the model in this scale, but still... you can see the ribbing on the sides of the gondola, and the hollow windows/interior. Bit of a step up from Takom's parts. Tailplanes rendered nicely. Sharp, crisp detail. And SUPER thin trailing edges. Again, a nice detail improvement over Takom's parts. Penultimately, a close-up of the envelope, showing the post-print surface. I haven't done anything more than cure the print here. Pretty much ready for a filler-primer, IMO. Might need the slightest rub down with some 0000 steel wool, or similar. The coolest thing about resin prints, though, is that you can use the same resin to join parts. Just a tiny smear of liquid resin, hold the parts in position, then give them a slight blast of UV light and they're cured as solid as the rest of the print. It's even more instant than CA. So of course, I put this to use, and a couple of minutes later...
  7. Glad someone gets it. So, another update. I figure, whilst waiting for my Elegoo Jupiter (hopefully arriving in May?), I might as well scale things down and print it in 1/350. It's pretty much just a direct scale-down - I made the envelope itself thicker so it would be rigid, but I haven't played with the 'rib tape' dimensions or anything - so it'll be interesting to see what prints and what doesn't, but it *should* be okay. Step 1 in print prep: add vent holes to the envelope. I'm using a resin printer, which uses a vat of liquid resin over top of an LCD screen (like a cell phone or tablet screen); a UV light shines from underneath, and the LCD screen masks off everything but the outline of each layer. A metal build plate comes down from above, the first layer is exposed and sticks to this, then it lifts up to peel that layer of cured resin off the the vat, then lowers back down to expose the next layer, repeating this cure, lift, lower pattern. This is important because, if you've got a hollow tube, it will create a strong suction force as the build plate raises and lowers. Like lifting an upturned mug out of a sink full of water. The way to solve this is to add an air hole at the top (or bottom, depending on your perspective - closest to the build plate) of the part, so that air and resin can freely flow in and out as it raises and lowers. As an added benefit, these air holes serve as alignment points to help assemble the completed envelope. Next the envelope is chopped into individual sections. Again, you can see the vent hole I've cut in the part. Smaller items like the tailplanes and gondolas are prepped for print, with pour stub-like supports. I could add individual supports in the print software (you may have seen the forest of rod-like supports on other 3D printed parts), but felt this would produce better results for these parts. Then the parts are all saved in a format the 3D print software can read. And opened in said 3D print software. This converts the various 3D models into individual layer slices. In this case, it's basically a whole bunch of JPEG files stacked on top of each other, with a little bit of machine code to tell the printer how long to expose each layer, how fast to raise and lower, etc. I've doubled up the gondolas and tailplanes because they don't take much resin, and being smaller, they're more prone to failure. This way, I'm more likely to get a good print. (now watch the biggest envelope part fail...) And then the models are converted for printing. The left side shows the printer's build plate at a particular layer; the right side shows what the LCD will expose for that layer - in this case, layer 145 of 3001 total layers, or some 12 hours total print time.
  8. It'll be about 110 cm, or 44" long. Bit bigger than your average 1/144 fighter.
  9. Okay, moving forward... I thought I'd do a deeper dive into the construction of the gondolas. So here's a bit of a step-by-step. This is just the processes involved; every process involves at least one sketch, which is the time consuming bit as you try to interpret the references and make an accurate part. These sketches and processes tend to layer on top of each other, so if you find out you did something wrong earlier in the design, it can break subsequent steps, which means you've got to go back and repair things, so it can be a tedious process. Tl;dr: it's not as easy as it looks I decided to start with the main windows. You have to start somewhere, and they seemed like a fairly central detail to 'hang' subsequent operations on. (hard to see, but) next is a loft underneath, to blend the main, square section of window with the bottom of the gondola. Then the front bottom of the gondola is extruded with a slight taper. ...and cut to shape. The mid section is extruded from the roughed out front section. And the various sketches completed so I can create a loft for the aft end of the gondola. The cross-sectional sketches form, well, the cross-sections of the loft, but they have to be told where to go, or else they'll simply take the straightest path (or occasionally, a random, wild path...). This requires additional sketches floating in space, to connect the cross sections. It's actually a bit of a process to create these - flat planes are simple to trace, but sketches that are fully 3D end up requiring a ton of preparation and tweaking to perfect. I'll often extrude, cut and loft temporary bodies so I can trace their (3D) outlines to get the necessary 3D sketch... then delete the bodies and use the resulting sketch to guide the loft. All that prep work done, the loft is completed. I only did one half as it was easier to force the loft to do what I wanted. I can mirror it later. The roof is then extruded... ... and the entire model gets chopped in half. This wasn't my original plan (or else I'd only have done one side of the front section) but after screwing around with the loft for a while, I decided it was the best option. Doing two lofts side by side ran the risk of causing problems meshing with the rest of the model; mirroring just the loft might have worked, but in the end, cutting it in half gives me a single, flat surface I can use to mirror the other side, for a simpler construction. It boosts the file size a bit, since it's more process-intensive, but I felt it was worth it. Mirrored. The final step to rough-out the gondola is to create a loft at the front of the roof. This is a great example of using sketches to 'force' the loft into place - I'm trying to merge a triangle into a weird, six-sided shape. Each of those grey lines tells the loft to go from point A to point B. Without them it would fail, as it can't reconcile the the 'start' and 'end' sketches. [img}https://i.imgur.com/GYeZpzd.jpg[/img] And the gondola is roughed out. This completed body is then duplicated so that I can add details. One body is hollowed out to create the main part of the gondola. The other body is shelled outwards, adding thickness, so that I can model the raised surface details. Here you can see a portion of the outward shelled body cut away, exposing the window area. The ribs are then cut out and merged with the main body. I now have raised ribs on a hollow gondola. Time for some windows. The rear, open section is cut out. Front windows are recessed. Front windows are then cut out. I've left a .25mm lip around each pane to fit a piece of acetate, once printed. The left side's windows then get mirrored onto the right, and the front window is cut out. And the side windows are done in the same manner. The access hatch is cut in the roof. Incidentally, most Zeppelin kits seem to include this as a 'tube' between the gondola and envelope; this doesn't seem to be correct, from my readings. As far as I can tell, it was open there, so you'd get a blast of icy air traversing the Zeppelin. This solid bit is added. Not quite sure what to call it - it covers the connections between the gondola and the airship. Finally, the rear bumper is added and the gondola is complete. I'm probably not going to detail the interior of this one; you really can't see it on the finished Q class, so there isn't much point. Phew. And THEN, I did all that all over again, for the rear gondola! And with THAT done, I could start buttoning up the envelope model. A new assembly was created and the scale drawings were turned back on, to help with locating everything. Note that, after correcting the section spacing, the model no longer lines up with the scale drawings - they're wrong, mine is (more) right. Hence the slight discrepancy. The gondolas are imported and lined up. I can now make location holes for the struts, rigging, access hatches and such. Like this. They may not fully print, but the holes should at least give me a slight recess as a location point for drilling. Next up: completing the gun platform, then prepping all the individual parts for print. This is about where my enthusiasm wanes, as I'm still waiting for my large-format printer; the itch to wrap my head around the shapes is mostly scratched, and I'm stuck twiddling my thumbs. Oh, and as a particularly annoying kick in the balls... a different company has announced ANOTHER large-format printer, which is a whopping 1cm bigger, should be available sooner, and only slightly more expensive. That 1cm may not sound like much, but it's JUUUUST enough to print all of the height climbers.
  10. Just remember, you can do a reasonable job bridging in FDM, but you can't really bridge in SLA - at best, the first layer is a floppy film of resin that's half the thickness of a sheet of paper ; at worst, it'll be a floppy, thin film of resin that simply tears off the part, sticking to the FEP. This is the 'tentpole effect' - it's like a sheet of fabric being held up by tentpoles, sagging in between them. This is why the surface facing the build plate is never as crisp as the surfaces facing away from it.
  11. Unfortunately, you can't just magic up any shape you want with a 3D printer. You need to design for the medium. The steps I'd take to troubleshoot, from least to most work/lowest to highest chance of success... Calibrate your resin with a RERF to find the best exposure time. Print the file straight off the build plate, if you can, rather than using supports. Add a ton of supports under the overhangs. These areas will never be perfectly flat, due to the 'tentpole effect', but the more supports, the closer they'll be. Add a hole to the side of the stacks. As it is, you're printing suction cups; a small hole in the side will allow airflow and eliminate the suction. Thicken the thin walls at the front and back of the model. Adding supports to their sides for lateral stability will also help. Consider revising the model, to remove the thin, flat overhangs. You could easily skin these areas with styrene sheet instead. This would get you closer to your original design.
  12. Next, attention moves to the tailplanes. These were sketched out, then more complete detail drawings made, before the actual modelling was begun. First, the framing is extruded: Then the 'fabric' is extruded - slightly thinner than the framing, to give slight relief. Then various details added - the rudder trailing edged were chamfered to a thinner edge, fillets added to the tailplane leading edges, control horns(?) added, etc. And the same process was repeated for the horizontal tailplanes. The envelope was copied, then a thin shell is created as the basis of the framing detail. The frames were then marked out and the areas between cut away from the shell, leaving a series of thin 'rib tape' rings, which are then merged with the original (correct size) envelope: And finally, detail areas were cut out from the almost-complete envelope: windows, the gun platform, rigging points, etc.
  13. Sooo... how to design a model kit. The first step was to scan the scale drawings, re-size them to the correct scale dimensions, then carefully trace the key dimensions - the outline of the airship, location of the tails, gas cell locations, etc. This is a fairly slow, tedious task with a lot of time spent fretting over fractions of a mm (mostly needlessly) and wondering which side of a line to trace to. This process also serves to get the gist of the shapes into my head. It familiarizes me with the intricacies of the subject and just generally helps me get up to speed. With that done, the actual design work can start. A cylinder with the diameter of the envelope was extruded for the nose, then excess was cut away to form each individual facet. The same process was repeated for the tail. There's also quite a bit of cross-checking with the scale drawings and with reference photos, to ensure the creases are formed in the right locations - it's not just a simple 17-sided structure. ...and then a simple loft in between the two sections to finish the raw shape of the envelope. With that done, I turned my attention to the keel, creating a loft to form the front end: ...then the back... ...then the transition sections... Before completing the centre section: Which seems fairly straightforward, but required a bunch of planning, tweaking and revision. The loft tool is powerful - it can make complex 3d shapes - but it's also kind of dumb and doesn't always do what you want it to. It needs to be able to connect each vertex - each 'point' - from one sketch to a matching point on the next sketch. Try to loft a square into a triangle, for instance, and things can go haywire.
  14. I'm currently awaiting delivery of a large format resin printer, so while I wait, I've been designing another Zeppelin model to print on it: Z XII. Z XII was one of the first Zeppelins built during the Great War and the only N Class Airship. As an early war design, in many ways it bridges between the pre-war passenger airships and the war time bomber/recinnaissance airships. It introduced changes such as the duralumin structure and central keel, but maintained the external keel gondola of the passenger airships. The gondolas were enclosed, with the front using a pusher propellor for the first time, while the airship lost the venetian blind-like array of tailplanes for a simpler, cruciform tail structure. It had a successful career spent mostly on the Eastern Front, before being retired to training and development and, astonishingly, managed to survive the war. It was the first airship to bomb Paris, the first to use an external 'sub-cloud car' for navigation, and it was the first aircraft to use a standoff guided weapon: the Siemens Torpedo Glider. This is how I plan to finish my build, in a late-war sheme with dark envelope with a lighter top section, and a pair of torpedo bombs slung underneath. ...as seen here, which also happens to be my primary reference, using the excellent scale drawings contained therein. The volume covers the history of all the early Zeppelins used in the war, with special focus on Z XII and the O Class ship LZ39.
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