johnlove_mk_II Posted February 10, 2022 Author Share Posted February 10, 2022 The J-2 is coming along well. Not absolutely perfect, but I'm pretty satisfied so far. I keep reminding myself that this is 1/72 scale and a tube not having the absolute perfect curvature isn't going to be the end of the world, especially if it's to be partially obscured by some other little detail. Quote Link to post Share on other sites
habu2 Posted February 10, 2022 Share Posted February 10, 2022 The conical thrust structure attaches to the elliptical bottom of the LOX tank, so there is a distinct gap around the lower skirt and the tank bottom. (ingore the yellow ring) Quote Link to post Share on other sites
johnlove_mk_II Posted February 10, 2022 Author Share Posted February 10, 2022 Hi Habu - I know, it looks a little weird right? I decided to model it as close to "launch-ready" as possible so I'm including the rarely seen impingement curtain that bridges that gap between the edge of the thrust structure and bottom of the aft skirt. (I think it's there to protect the aft skirt equipment boxes from the S-II retros.) Not sure what it's made of exactly, because I've found very little info on it, but it does have what looks to be zipper closures for accessing the equipment and such. I still need to add the surface details and make it look wrinkled somehow. Here's the best information I've been able to find about it. (Technical Memorandum No. 136 - S-IVB Configuration Sketches, McDonnell Douglas Astronautics) Quote Link to post Share on other sites
habu2 Posted February 10, 2022 Share Posted February 10, 2022 Interesting, I was unaware of this cover. Carry on……. 👍 Quote Link to post Share on other sites
johnlove_mk_II Posted February 13, 2022 Author Share Posted February 13, 2022 Here's the J-2 so far. Think I'm getting there, but there's a lot of little things to add. Quote Link to post Share on other sites
aircommando130 Posted February 13, 2022 Share Posted February 13, 2022 There was nothing like standing on the beach and watching a big Saturn V go! Saw three of them...Apollo 9, 10 and 11! Thanks dad! Great work so far! Cheers...Ron Quote Link to post Share on other sites
K2Pete Posted February 14, 2022 Share Posted February 14, 2022 It's ALL those "little things", the "do-dads". the Greeblies that makes these miniatures look as actual as they can ... This is really looking good! Is your reference based on Photos or do you have Engineering Drawings from back then? Keep up the terrific work! Pete Quote Link to post Share on other sites
johnlove_mk_II Posted February 16, 2022 Author Share Posted February 16, 2022 Thanks guys! Information on the J-2 is pretty scarce, so most of my references are photos. When I visited KSC a few years back I spent a few gigabytes on the J-2 they have there in the garden. I got a total walk-around and way more detail shots than I likely would have ever needed. I did get my overall shape from one of the few three-view drawings I've found, then I just started adding things in as best I could with a ton of dead-reckoning using the photos. Been a slow go of it lately, and I'm kinda tired of the J-2, so I'm going to work on the thrust structure for a bit. Got a start on the ambient helium tanks that populate the thrust structure, but they need way more work. Here's a look at what I've got so far for the entire S-IVB. Quote Link to post Share on other sites
johnlove_mk_II Posted February 26, 2022 Author Share Posted February 26, 2022 Finished up the J-2, now to try to get it to print. Setting up for that today and hopefully should have some freshly minted J-2s sometime tomorrow. Decided to get all the propulsion out of the way first so I'm digging into the F-1s currently. Going to try to model them with the TPS blankets, which will likely require that I learn some Blender. So the plan is to design the foundation in Rhino first and then add the wrinkled texture and such via Blender. That's the plan anyway. Fingers crossed. Quote Link to post Share on other sites
johnlove_mk_II Posted March 4, 2022 Author Share Posted March 4, 2022 The first proof print of the J-2s is complete. Was hoping to do the first print this weekend but I discovered that my resin had gone funky so I had to order a new bottle. I'd say I'm about 95% there. There where no failures but I think I may have been a little too heavy-handed with the supports. (Some of the details where obliterated during clean-up.) Going to try again with an updated support scheme and I might dial back the exposure time ever so slightly. Pretty chuffed at how these guys turned out. Quote Link to post Share on other sites
habu2 Posted March 4, 2022 Share Posted March 4, 2022 Impressive ! Quote Link to post Share on other sites
CaptKirk Posted March 4, 2022 Share Posted March 4, 2022 Very nice! It's so good to see models turn from CAD to physical objects; a combination of 2 great skills. Quote Link to post Share on other sites
K2Pete Posted March 4, 2022 Share Posted March 4, 2022 COWABUNGA!! Those DO look GREAT! The spheres on the prints, did you sand 'em smooth or is that how fine the resolution is now? Man oh Man, I'd be chuffed too! Nicely done! Pete Quote Link to post Share on other sites
aircommando130 Posted March 5, 2022 Share Posted March 5, 2022 That is awesome! As said by Jack King....the voice of Apollo Launch Control! Cheers...Ron Quote Link to post Share on other sites
johnlove_mk_II Posted March 5, 2022 Author Share Posted March 5, 2022 Thanks everybody! The second (and third) prints, with the new supports, completed without issue. I now have a baker's dozen of perfect J-2s ready to roll. Pete - Those are straight from the printer with no sanding or anything. The Elegoo Saturns have a 4K resolution so there's very little stair-stepping. You really have to take a magnifying glass to see it at all, which is awesome. Quote Link to post Share on other sites
as205 Posted March 8, 2022 Share Posted March 8, 2022 At what angle did you print them? They came out fantastic! I've got a Mars 2 Pro with the 4K screen and I'm thinking about taking a wack at some F-1's that I found on Thingiverse. I might end up drawing them from scratch if they don't look good. Randy Quote Link to post Share on other sites
johnlove_mk_II Posted March 9, 2022 Author Share Posted March 9, 2022 22 hours ago, as205 said: At what angle did you print them? They came out fantastic! I've got a Mars 2 Pro with the 4K screen and I'm thinking about taking a wack at some F-1's that I found on Thingiverse. I might end up drawing them from scratch if they don't look good. Randy The final prints were straight up and down. Like this: On my first attempt I did have them canted 45° and they came out ok, but there were way too many supports to clean up in critical places. Quote Link to post Share on other sites
crackerjazz Posted March 9, 2022 Share Posted March 9, 2022 (edited) That's incredible, John! They look like real injection-molded kit parts : ) Did you have to hollow-out anything or make any drain holes? Edited March 9, 2022 by crackerjazz Quote Link to post Share on other sites
as205 Posted March 9, 2022 Share Posted March 9, 2022 Thanks for the tip. I'll be trying that out when I get to printing some. Quote Link to post Share on other sites
johnlove_mk_II Posted March 14, 2022 Author Share Posted March 14, 2022 Thanks Jazz! I'm really pleased with how the Elegoo Saturn is performing – everything, so far, has printed beautifully. Oh, and I added no drains ... thought about it, but found that it wasn't necessary because of the small-ish size. Getting ready for the next round of printing so I started concentrating on the S-IVB thrust structure. Got most of the main items – now for all the fiddly bits. Quote Link to post Share on other sites
spaceman Posted March 14, 2022 Share Posted March 14, 2022 Incredible 3D modelling, John, the rest is done by your first class printer you can rely on. Keep it up! I stay tuned amazed ... Quote Link to post Share on other sites
crackerjazz Posted March 14, 2022 Share Posted March 14, 2022 (edited) That looks fantastic, John : ) What resin are you using, by the way and how were you able to tell it was going? I just picked up a bottle of plant-based resin and it says best before 2022 02 03. I may need to use up the whole bottle soon. It doesn't spoil all of a sudden does it? : ) Also have a question regarding cleaning. I notice on my prints that there's some resin in between tiny details that hasn't completely flowed out and probably wasn't completely removed by swishing in IPA and then had solidified. I did try to clean the parts thoroughly though, even taking a paintbrush to all the nooks and crannies before curing the part under the UV lamp. Was thinking about using a toothbrush but I was afraid it might harm the softer sections if any. Is it possible that the lights in the room emit some UV that starts to solidify resin even while you clean the parts? Edited March 15, 2022 by crackerjazz Quote Link to post Share on other sites
johnlove_mk_II Posted March 17, 2022 Author Share Posted March 17, 2022 My bottle had some like filmy globs. Thinking back it honestly just looked as if maybe the top had filmed over because it had been exposed. I probably could have just filtered out all the solids, but there was only about a third of a bottle remaining so I just decided to not risk it and started with a fresh one. I'm just using the standard Anycubic grey 405nm stuff. A 1kg is like $24, a heck of a deal. For cleaning I've invested in one of the cleaning and curing stations. It really saves a ton of time and the parts come out flawless. I found the one I have for less than $90 shipped on eBay. It's kind of a luxury but it's so nice to just plop the parts in for a few minutes and have the machine do all the cleaning. Quote Link to post Share on other sites
johnlove_mk_II Posted April 10, 2022 Author Share Posted April 10, 2022 Finished up the forward and aft skirts for the S-IVBs. Started printing last week, it took three iterations to finally get a near flawless print of the aft skirt. I learned a lot, so going forward I hope things will proceed a little more smoothly. Printing the forward skirt as I type this ... should have a semi-complete S-IVB in about six and a half hours. Quote Link to post Share on other sites
GeneK Posted April 14, 2022 Share Posted April 14, 2022 (edited) On 3/14/2022 at 5:32 PM, crackerjazz said: I notice on my prints that there's some resin in between tiny details that hasn't completely flowed out and probably wasn't completely removed by swishing in IPA and then had solidified. Use an airbrush to blow out excess resin trapped in small nooks. Once after the initial swish, and again after the final IPA wash. Speeds drying the IPA. Gene K Edited April 14, 2022 by GeneK Quote Link to post Share on other sites
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