Monday, April 6, 2009
Blog Moved!
The Nescorna Rocketworks construction blog has moved, to http://blog.NescornaRocketworks.com.
Tuesday, March 31, 2009
Plans and Details
I ordered some Apollo plans, scale drawings with color schemes, produced by David Weeks (RealSpace Models). 1:48 scale, Block I and Block II, including (some of) the details on the EVA rails. Along with a couple of other diagrams and mission photos (in hand now), I'll have enough details, I think, to model Apollo 15 pretty accurately.
Next steps: finish the LES, decide which spirals to fill in the tubes and fill those, check for defects and gaps in the wraps (plastic and paper), prime, and paint. Oh, and attach the various jellybean parts to the different stages.
Next steps: finish the LES, decide which spirals to fill in the tubes and fill those, check for defects and gaps in the wraps (plastic and paper), prime, and paint. Oh, and attach the various jellybean parts to the different stages.
Wednesday, March 18, 2009
Apollo 15 Details
As I get closer to finishing building the Saturn V's structural components and beginning the finishing, it's time to think some more about Apollo 15's details.Apollo 15, 16, and 17 included a space walk for the Command Module Pilot during the trip back from the moon. (This wasn't just to give the CMP one of the cool things on the mission, a sort of consolation prize for minding the store while his buddies cavorted on the moon. There was some film to retrieve from some additional cameras in the SM. Remember, 1970, no digital cameras with wires to remote memory.) To assist the CMP on the journey from the CM to the SM, a set of rails and foot holds was added.
The rails on the CM leading from the hatch to the SM are covered by the BPC (boost protective cover, in place until the launch escape system is jettisoned), so those are not visible during launch. The rails along the top and sides of the SIM bay (Scientific Instrument Module), though, are visible on the pad and during launch.
Questions, then: how big, how long, how many, and just where?
Tuesday, March 17, 2009
To Fill and Sand?
The end of construction is in sight! I might even wrap up this evening, completing the LES and building the RCS nozzles (gotta love NASA's plethora of TLAs, eh?).Soon, I'll need to decide whether to fill the spirals in the body tubes or not, or maybe to fill just some (e.g., the S-IVB). Sure, it will look nicer, assuming I have the patience to do a good job. My biggest concern is that I might damage one of this crazy vacu-formed wraps, or even the paper wrap on the LM shroud. As it is, I have just a little repair work on the wraps yet, including patching a gap in one of the wraps (it was about 2mm too short, and, even though the joint is beneath one of the tunnel covers, the tunnel cover extends only part way up the wrap).
Sunday, March 15, 2009
LM Shroud Done
We're building the stack from the bottom up. Most recently, I've completed the LM shroud transition, atop the S-IVB. Next up will be applying the SM wrap.
The rocket is starting to look like a Saturn V! There's a long way to go yet, but with the CM atop the SM tube, even without the wrap, the silhouette is sure familiar (though still missing the LES atop the CM).
No serious problems, though, since that misaligned S-IVB wrap.
The rocket is starting to look like a Saturn V! There's a long way to go yet, but with the CM atop the SM tube, even without the wrap, the silhouette is sure familiar (though still missing the LES atop the CM).
No serious problems, though, since that misaligned S-IVB wrap.
Monday, March 9, 2009
Mis-aligned Wrap!
Oops.
I mis-understood one of the alignment instructions. It was plenty clear: I merely blew it.
The S-IVB has two wraps to model the ribs, one on the forward end of the stage, one on the aft end. There's a tunnel cover that stretches between them (overlapping each). So, the alignment mistake—about 20° off, rotated around the body tube—is more than just cosmetic, since there are flat spots in the wrap where the tunnel covers attach.
What to do?
I thought about just cutting the wrap where the tunnel cover needs to go, perhaps using the cut piece as a graft over the molded-in flat spot. I considered cutting the body tube in half, making a stage coupler, and rotating the two pieces to align the wraps correctly. I briefly gave thought to ripping off the wrap and replacing it with a new one.
I decided to try to remove the wrap and reapply it.
Some parts of the wrap came off the body tube very easily, but some were extremely difficult to remove. Where the CyA didn't wick very far under the wrap, it came off easily.
I used a hobby knife, very gingerly, to pry the wrap up, occasionally using CyA debonder to try to dissolve the CyA. (I'd tested it on some wrap scraps.) In a few spots, I had to cut a layer of the body tube away in order to lift the wrap off. There's one bad tear, a nick, and a couple of very small cuts, but the wrap came off in a reusable condition!
It's now back on the tube, properly aligned. Rather than wicking CyA again, I used canopy cement: I didn't want to take a chance on the wrap dissolving or cracking more from the CyA, so I just applied a thin layer of canopy cement to the edges of the wrap, laid it up, and taped it to the tube. Back in business!
I mis-understood one of the alignment instructions. It was plenty clear: I merely blew it.
The S-IVB has two wraps to model the ribs, one on the forward end of the stage, one on the aft end. There's a tunnel cover that stretches between them (overlapping each). So, the alignment mistake—about 20° off, rotated around the body tube—is more than just cosmetic, since there are flat spots in the wrap where the tunnel covers attach.
What to do?
I thought about just cutting the wrap where the tunnel cover needs to go, perhaps using the cut piece as a graft over the molded-in flat spot. I considered cutting the body tube in half, making a stage coupler, and rotating the two pieces to align the wraps correctly. I briefly gave thought to ripping off the wrap and replacing it with a new one.
I decided to try to remove the wrap and reapply it.
Some parts of the wrap came off the body tube very easily, but some were extremely difficult to remove. Where the CyA didn't wick very far under the wrap, it came off easily.
I used a hobby knife, very gingerly, to pry the wrap up, occasionally using CyA debonder to try to dissolve the CyA. (I'd tested it on some wrap scraps.) In a few spots, I had to cut a layer of the body tube away in order to lift the wrap off. There's one bad tear, a nick, and a couple of very small cuts, but the wrap came off in a reusable condition!
It's now back on the tube, properly aligned. Rather than wicking CyA again, I used canopy cement: I didn't want to take a chance on the wrap dissolving or cracking more from the CyA, so I just applied a thin layer of canopy cement to the edges of the wrap, laid it up, and taped it to the tube. Back in business!
Monday, March 2, 2009
Are the Wraps Just Old?
I applied the S-IVB transition wrap this evening. It cracked.
There was a little stress on the wrap, tangentially, in order to keep it tight. The CyA created a few cracks in the forward (small) edge. (Side note: I probably should have just glued this wrap down to the paper transition with canopy glue. I'm using that on the edge joint and on the aft [large] edge: I didn't want to take another chance with this wrap.)
I wonder if these wraps are just a little old. Does the chemistry of the wrap change slightly with age, making them more susceptible to developing these small cracks? I bought the kit about ten years ago.
There was a little stress on the wrap, tangentially, in order to keep it tight. The CyA created a few cracks in the forward (small) edge. (Side note: I probably should have just glued this wrap down to the paper transition with canopy glue. I'm using that on the edge joint and on the aft [large] edge: I didn't want to take another chance with this wrap.)
I wonder if these wraps are just a little old. Does the chemistry of the wrap change slightly with age, making them more susceptible to developing these small cracks? I bought the kit about ten years ago.
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