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johnlove_mk_II

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  1. A bit of a bear, these things. It's taken a little while to get to this point but I'm pretty close to finalizing and sending the parts off to Ponoko for cutting. It won't be an exact representation, but it should be robust and will hopefully look the part. Still need to sort the equipment boxes and other trust structure details ... but hey, it IS progress. Also the S-IC forward skirt details arrived this weekend from Shapeways. I think they turned out pretty well. I have a few little details to work through, then I will start the final assembly of the S-ICs.
  2. S-IC forward skirt details - continued Finished modeling the equipment boxes and LOX vent line parts. I was planning to print one set of these at Shapeways and then cast all the ones I would need in resin. I was thinking that it might be more cost effective but it turns out it’s only going to be $17 bucks to print them all. So yeah - I'm just going to print them all and be done with it. Hope to see them in the next week or so. S-II - Getting started and thrust structure ideas As I've mentioned previously the S-II will be a rather piecemeal affair. I will be using the kit's aft skirt and tank parts and will utilize a section of a donor skirt from a third kit for the forward skirts. T’ll be adding the extra stringers to the aft skirt and will also add the smaller “intercostal” stringers to the forward skirt. The forward skirt stringer count will be off, but it should look reasonable, and will mate up with the S-II/S-IVB interstage which also has the wrong amount. I'm hoping these will go together quickly and So for the last few weeks I've been pondering how to tackle the S-II thrust structure. I think that I've come up with a solution that will be relatively easy, though somewhat tedious, and should not cost a fortune to execute ... twice over. Still working out some details, but I'm getting close to finalizing the design. (Ponoko will certainly be getting more business ... I am NOT cutting these things out by hand.) Here a start of some of the patterns that will be used.
  3. Finished the second skirt interior and cobbled together the ODOP antennas. I'll attach them after I complete adding the extra stringers to the interstage and the S-II aft skirt. (I'll want to sand them all so they're uniform.) Now there are two. ODOP, telemetry and range safety antennas.
  4. The last month was busy for me with birthday parties and work trivialities … but we’re back at it, nose to the ‘stone. Been struggling with the laser-cut interface ring parts. The first set had a little fitment issue so I had another set cut. This time I added a doubler to help stiffen them but unfortunately these too were slightly off and out-of-round. I’m guessing the styrene does shrink a little more than I was expecting. I went ahead and cut the parts with the Silhouette and they came out far more accurately. So yeah ... some progress.
  5. Thanks guys. I'm trying not to be too critical, especially with these, but ... you know. 😉 Didn't get to work very much this weekend, but I did start on the skirt interiors. Had to remove some vertical "guide" plastic doodads and then lay in the structural rings and vertical "stiffeners". Still need to add the little diagonal struts that attach to the interface ring and center ring.
  6. Just decided to proceed with the LOX bulkheads as they are. They look a little off, but with the added details they don’t look too bad. Besides, they’ll be tucked away out of sight for most of the rest of their existence. Adding the various access ports and whatnot. The bulkhead placed inside the skirt with the interface ring. Not horrible.
  7. I can see what you mean. They do curve, just not nearly as much as they should ... and at the angle the photo was taken, which is almost straight on, they do look really wack-a-do. I think that since the dragon part is not so much ellipsoidal as it is spherical, that's what makes the weld curvature less pronounced. But yeah, I'm already thinking of creating a balsa plug and vac-forming properly shaped parts.
  8. S-IC Forward Skirt Interiors - LOX tank bulkhead The weld lines look low ... but with the weird "Dragon" parts, I'm afraid thats as good as it gets. Here's one of the Marshal built S-ICs bulkheads for comparison. Started adding the "weld" details to the tank bulkheads yesterday evening. The original bulkheads were made up of 16 gore sections, 8 base sections and 8 apex sections. The "Dragon" parts only represent the welds that go from apex to base so I used styrene strip to add the missing horizontal welds. As I was adding them it wasn't looking quite correct. I'm guessing that the since the 'Dragon" dome was a little off shape-wise, it was causing it to look a little off to my eyes. I think I'll just continue adding detail and see if it doesn't start looking more "right" ... or at least acceptable. I may also sand down all the "welds" to about half they're current height as they're a little too proud of the surface. At that scale the welds would be as big around as a beer can. Just for fun I stacked up one of the S-ICs on the Apogee Motors. These things are going to be huge.
  9. This is sort of a housekeeping post. I've been working on tying down details and how to proceed with construction ... so fair warning, there's not a lot to see here. All planning and no construction make Jack a dull boy. S-IC Forward Skirt Interiors - The interior plan is set ... Shapeways parts are ordered I think I've got my forward skirt research pretty much squared away. I tell ya, there's nothing like piecing together details from close-up photos, that darn stage lifting fixture is always in the fricken' way. The structure of the forward skirt is pretty interesting from a engineering standpoint. It is made up of three circumferential support rings attached to 12 skin panels. That assembly is further reenforced by the 216 external stringers. The stringers transmit the longitudinal loads, via the upper most support ring to the interstage and then on to the S-II. Cool. Here's one of my "working" drawings showing tank and skirt detail locations I was hatching this grand plan to have the three support rings and the internal stiffeners laser cut. But thinking on it further I've decided that I didn't want to deal with the down-time waiting on those parts to arrive. Given that the models will be stacked 99% of the time I've just decided to use styrene strips and rod. I'm finalizing the pattern for the layout and start on that on that part of assembly shortly. Oh yeah, I also already had the uppermost support rings cut when I had the umbilical details cut ... so I do already have those. I had already completed considerable research on the LOX tank bulkhead from my previous endeavors. I just had to adjust the drawing to the weird Dragon part. I'm debating on whether to remove the molded "weld" lines then add my own ... or just to roll with it. I'm leaning towards just using them as they are and adding detail. That seems to be inline with the spirit of this build. I also sent off the equipment box and LOX valve parts to Shapeways for printing. I hope to see those within the next few weeks.
  10. Thanks ApolloMan. Indeed, those are Evergreen strips. The application is rather tedious, but I think the end result is worth the effort. If only Dragon had taken the time to get it correct in the first place. As far as the separation motors around the interstage. I understand that they discovered that the rate of separation at staging was higher, or sufficient enough, where they were considered to not be absolutely necessary. The resulting weight savings allowed for things like more fuel for the LM descent stage, SIM bay experiments in the Service Module and Lunar Rovers and such. Hotdog - I reconnected the images, can you see them now?
  11. Finished up adding the forward skirt umbilical details. Moving on to the interiors. This part is done. Two S-IC stages. Cool beans.
  12. Strange. I went in and relinked the image and it looks like it's showing as it did before. All big like. S-IC Forward Skirt Interiors - the kit tank parts are rubbish. Go figure. Still working on the forward skirt interiors and, of course, that means a 1:1 drawing of the kit parts and their relation to the parts I wanted to produce. Measured out the skirt and it's a few millimeters longer than it should have been. I could have trimmed it down to the correct size but I didn't bother. Interestingly, and I think it's been covered elsewhere, the skirt cylinders are slightly tapered. Probably to help with part removal during the injection process. It's very slight but does add a bit of complication. The other thing that was sort of a surprise is how "off" the kit provided tank dome parts are. If you look at the drawing below you can see that the original bulkhead shape (dashed line) is much more bulbous and is considerably wider. The kit's parts ... not so much. I'll be proceeding with the kit parts but will have to make some adjustments and tweaks to get it to look presentable.
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