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Thread: Middle-aged kit building

  1. #451
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    http://www.astronautix.com/v/vonbraunlunarlander.html
    I recognised the 'table' that holds the fuel tanks etc.

  2. #452
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    Quote Originally Posted by eburacum45 View Post
    http://www.astronautix.com/v/vonbraunlunarlander.html
    I recognised the 'table' that holds the fuel tanks etc.
    That's the one. This seemed like a good year to be building it.

    Grant Hutchison

  3. #453
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    Too bad you can’t build an “as flown” version.

  4. #454
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    It's interesting that the photo in the Astronautix link shows Wernher von Braun holding a model that has the same "unrealistic" configuration as the Pegasus model I'm building. The very large, outermost spherical fuel and oxidizer tanks were intended to be used for translunar injection, and then discarded, like the S-IVB stage. During that acceleration phase, the legs were to be stowed out of the way of the rocket plumes - the outer ones folded forward, and the central one retracted. They were only to be deployed during the final powered descent to the moon, by which time the vehicle had a more stripped-down appearance. And the central leg was only the same length as the others once the vehicle had landed - it was intended as a shock-absorbing "probe", and initially extended beyond the plane defined by the footpads of the outer legs.

    I'm modifying my kit to depict the landed configuration.

    Grant Hutchison

  5. #455
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    Thirty rocket motors! A crew of fifty! That's a spaceship. The mission seems to have been modelled on the Endurance or Discovery in the Antarctic.

  6. #456
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    Quote Originally Posted by eburacum45 View Post
    Thirty rocket motors! A crew of fifty! That's a spaceship. The mission seems to have been modelled on the Endurance or Discovery in the Antarctic.
    Here's the engine array:
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    The outer twelve could be vectored in triads for attitude control:
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    According to the 1952 Collier's article, the expedition crew of 50 would have travelled in three ships, one of which replaced the lunar departure tanks (in the centre of the structure) with a cargo hold. Each ship could accommodate 25, so that the two with return take-off capability could get everyone off the moon.

    Grant Hutchison

  7. #457
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    Three ships would require 90 rocket motors.
    The same number of rocket motors were used in three N1 launches. Not a resounding success.

  8. #458
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    And of course, the BFR Starship/Superheavy is going the same way.
    Cum catapultae proscriptae erunt tum soli proscript catapultas habebunt.

  9. #459
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    But with fins. And no worry about a hypergolic disaster.

  10. #460
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    1/350-scale astronauts.
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    1/350 is a common scale for ship models, and I managed to find some figures in that scale, to which I applied little bits of styrene strip for life-support packs, and a blob of glue for a bubble helmet. Bit of a challenge to paint, as you can see.

    Grant Hutchison

  11. #461
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    Mercy, that's tiny!

    My first reaction to the photo was that your pennies are quite a lot bigger than ours. They aren't that much, just 1mm and change.
    Cum catapultae proscriptae erunt tum soli proscript catapultas habebunt.

  12. #462
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    Click image for larger version. 

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    Grant Hutchison

  13. #463
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    Quote Originally Posted by grant hutchison View Post
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    Grant Hutchison
    Now weld some stainless steel around it....
    Cum catapultae proscriptae erunt tum soli proscript catapultas habebunt.

  14. #464
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    Kicking up some dust ...

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    No, honestly. That's the size of it.

    Grant Hutchison

  15. #465
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    That is what should have been the first lander. Sigh....

  16. #466
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    Advice for sawing fine detail

    You guys might be just the guys to help me out with this.

    I'm planning to make a landscape relief map out of foam core layers (1/4" or 1/8"). It's mountainous territory, so the cutting will be very intricate - and a lot of it. I'll print out the landscape, paste it on, then cut along the contour lines. (The printed landscape will be the final surface.)

    I tried using an X-acto knife already. It was not up to the job. Even a #11 blade, that's only a mm or two thick, does not allow me to cut the curves I want. Worse, it doesn't cut cleanly through the paper and foam core, so the contour frays or falls apart.

    I'm looking for a better - and ideally faster - way to cut.

    I have a coping saw but a flat blade will still be problematic. Ideally, I can get a blade with a circular cross-section, so I can cut in any direction. Still, using a coping saw for hours on-end will probably rattle my teeth.

    I wonder if there are hand saws for this kind of work? I'm thinking like a micro-screwdriver, but instead of a bit, it has a blade with a circular cross-section. Then it would essentially be a human-powered coping saw.

    I also thought of a hot wire but, while it might go through the foam core fine, it likely won't handle the paper very well.

    Thoughts?

  17. #467
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    I don't have a good suggestion. I've used and cut foam core, but only as single layers, and an X-acto works fine.
    At night the stars put on a show for free (Carole King)

    All moderation in purple - The rules

  18. #468
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    Cut out the paper separately first (any way you see fit), put it on the foam, then follow the contour with the hot wire. That way the hot wire doesn't have to cut the paper. You spend extra time because you have to cut twice, but two easy cuts might be faster and more pleasant than a combined troublesome cut.
    With sufficient thrust, water towers fly just fine.

  19. #469
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    Quote Originally Posted by Nicolas View Post
    Cut out the paper separately first (any way you see fit), put it on the foam, then follow the contour with the hot wire. That way the hot wire doesn't have to cut the paper. You spend extra time because you have to cut twice, but two easy cuts might be faster and more pleasant than a combined troublesome cut.
    Thanks for the idea, but I think it will be problematic. Making circa-millimetre mistakes when cutting both is not a problem for me, but when cutting the foam to match the paper, even the tiniest divergence from the cut the paper, the edge will look terrible.

    And I've got a lot of cutting to do...

    This is about 18" square and has 20 layers.

    (I'd 3D print, but I think it's way too large/expensive. )
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  20. #470
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    Quote Originally Posted by DaveC426913 View Post
    ...
    (I'd 3D print, but I think it's way too large/expensive. )
    Rather than 3D print, I'd have thought that's more a job for an "old fashioned" CNC router table kind of thing.

    (Dunno about the detail achievable though.)
    Measure once, cut twice. Practice makes perfect.
    Wanna wake up every day and be the best clockmaker on Mars.

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