[3DP] Svetlana, the Red Menace!

Discussion in 'Digital Design and Fabrication' started by Tugboat, Dec 21, 2013.

  1. Tugboat

    Tugboat Facilitator RCWC Staff Admiral (Supporter)

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    [​IMG]
    Had to do it. So many hulls in the shop, and none of them printed, all are wood or fiberglass. Admittedly, this will go easier with the Rostock once its built (since it could print 2 cruisers in one massive print job), but it won't be up till January! Why wait a month (late January) when I could print one NOW! in smaller pieces? So, I got my plans into a jpg form, properly scaled. Deciding on a ship was tough. I want it to be relatively short, but something that could be armed and run in battle. And then I had to figure out how to get the hull form in Sketchup. Not being as gifted as Daniel is in this arena (see his Bismarck build!), I have kludged it and while it's not fast, it's reasonably quick, and the ship WILL be well within scale tolerances and look like it's supposed to. I imported the plan view into Sketchup, then lifted it up to where the main deck is supposed to be (vertically speaking) I drew one side of the main deck, then mirrored it on the port side. Then I raised the deck forward of the step. Crude and it will need some subtle refinements, no doubt, but it looks cool and it made me feel happy. I then added the first rib, which was tricky, but I've got the hang of it now. First pic:
    [​IMG]
    And so on... I added more ribs moving forward towards the bow from the step. But wait! As drawn, these ribs are not bevelled! That would be inconvenient to have to sand them. Why sand them when I can spend a couple extra hours in the design phase and save the plastic that would otherwise be sanded off. So we save time and plastic! And bevelling that 0.5mm off the front edges could save at least 5 or 10 minutes of print time in a 10-hour print! So below, you can see most of the rib bevelled down to the hard area, with a little left to be done. Note: The hard area inside is not done at all yet. It still needs water channeling and mounts for things. Those will be added later. But soon, we will have enough done to print the two bow sections and mate them up!
    [​IMG]
    I got the idea to do this from Bob Pottle, who laid out some possibilities in another thread. She's being built for IRCWCC combat, probably with a half-unit pump and four 1/2-unit guns. At speed 23, with pairs of 15-degree-off-centerline cannons in the casements, she'll be worthy of notice in battle by anyone who's not fond of double belows. Battleships can't outrun her, and convoys will hate her. Heck, the cruiser battle will be carnage :) For MWC use, she'll arm half the guns as 1-unit guns, and take the speed boost to 22 sec.
     
  2. Tanaaris

    Tanaaris Active Member

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    Impressive start! I will love to see how this one can be printed!
    2 things I did slightly differently:
    -I used the water line instead of the deck to line up my components
    -I waited a bit later in the design process before adding thickness to my parts and ribs. Initially I did like you, but then each small adjustment and modification needed also to take into consideration the thick parts. So I did the full set of ribs and parts in flat mode, and close to the end I added thickness.


    And one trick you can use for shaping your edge. After adding thickness, draw a horizontal line accros the ribs you want to shape down. Te line must be at the height where the shaping is not needed anymore. (this line present only on the shaped side of the ribs, will create a closed surface.) you can then pick and select the full curvature of your ribs (but only on the shape side) and scale it toward the inside.

    Good luck, and keep updating this thread, I want to see it coming along.
     
  3. Beaver

    Beaver 2020 Rookie of the Year Admiral (Supporter)

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    OOOHHH!!!!! I've been waiting for this thread!! Looking really cool!
    One thought though, you said that she would have a 1/2 unit pump, and 4, 1/2 unit guns. Under the IRC rules, it states that you can't split a one unit gun into two half unit guns. I'm not sure exactly where, but I remember seeing it.

    Keep us updated.
    Beaver
     
  4. Tanaaris

    Tanaaris Active Member

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    You are partly right.
    5 tells:
    Except as provided in section 11.e, below, a ship may mount only a single one-half (1/2) unit cannon in its offensive armament, and a whole cannon unit shall not be divided into smaller (1/2 or 1/4) unit cannons.


    Except that 11e) tells:
    Ships in Class 2 or smaller may use their battle units in one-half unit increments for either cannons or pumps.
     
  5. Anachronus

    Anachronus Well-Known Member

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    Its a baby Gangut. :D
     
  6. Tugboat

    Tugboat Facilitator RCWC Staff Admiral (Supporter)

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    Daniel is correct, Beaver. I thought exactly what you did up till about a week ago when Bob P. gently schooled me :)
     
  7. Beaver

    Beaver 2020 Rookie of the Year Admiral (Supporter)

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    Ah, see what you get when you don't read the rules enough.....:laugh:

    Beaver
     
  8. Tugboat

    Tugboat Facilitator RCWC Staff Admiral (Supporter)

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    Exactly what I said when Bob told me about that section ;)
     
  9. Beaver

    Beaver 2020 Rookie of the Year Admiral (Supporter)

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    What is that saying, "Great minds (sometimes don't) think alike" ;)

    Beaver
     
  10. Anachronus

    Anachronus Well-Known Member

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    My version of that is "warped minds think a like". You can decide which fits your needs best. :)
     
  11. Tugboat

    Tugboat Facilitator RCWC Staff Admiral (Supporter)

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    6 of one, half-dozen of the other... :)
     
  12. Tugboat

    Tugboat Facilitator RCWC Staff Admiral (Supporter)

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    I did look at how I was doing things in Sketchup, as Daniel said, there are more ways than one to do things. Then I discovered the obvious... I can do just the stbd side, and then mirror the who dang thing, saving a BUNCH of time over doing one rib at a time, etc. Expect printed boat parts to be seen shortly.
     
  13. Tugboat

    Tugboat Facilitator RCWC Staff Admiral (Supporter)

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    Making headway on the forward end. The stringer is coming along nicely, and I'm almost done with the ribs up there. I'll post a pic soon.
     
  14. Anachronus

    Anachronus Well-Known Member

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    How goes the Red Menace?
     
  15. Tugboat

    Tugboat Facilitator RCWC Staff Admiral (Supporter)

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    Slowly. doing the ribs is the easy part. Making the curved parts of the hull look good takes time! I didn't fully appreciate that earlier, but I want it to look good, otherwise there's no point in doing it. Currently evaluating the priority development work-wise, and leaning towards delaying Svetlana until the Rostock is printing and working more intensely on the printed Big Gun cannon. More people would benefit.
     
  16. Anachronus

    Anachronus Well-Known Member

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    I think you are right about the cannons being a priority.
     
  17. Remo

    Remo New Member

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    BTW Tugboat , I'v been working on automating the whole process you are doing by hand ( sculpting the ribs etc. ) It turns out to be a quite a bit more complicating than I hoped. But I''m getting there..

    Basically I do the hull in Delftship , export it to .obj file ( ONLY the hull ) and then run the program with instructions of where the ribs should be and it exports the keel , ribs , and deck with notches ready for printing in .STL format..

    I'm having some issues with the deck ( not all decks are flat , damn those engineers ), a slightly bent deck is not a problem , but lots of the ships have a raised deck at midship, and I the current triangulation code I have only works in a single geometric plane.

    I'll put the source on GitHub once I get a solution for the decks.
     
  18. Tugboat

    Tugboat Facilitator RCWC Staff Admiral (Supporter)

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    1) Totally awesome, I can't wait to see your work!
    2) The bent deck problem is an issue. The ships that have mostly-flat decks almost all have a step amidships. All the ones lacking a step amidships, have a slop to the line of the deck.

    My goal is to have the deck and ribs print as one part (albeit several printed sections will be necessary, since my print volume is 8" absolute max (7" is better to allow for finagling in the software of the printer). This is important because it lets me print parts like the gearboxes, gas bottle holder, pump mount, etc, as part of the hull, making it easy for a new captain who doesn't know where to put these to get into the hobby :)
     
  19. Remo

    Remo New Member

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    I have several options I'm looking at to solve the stepped decks.
    1. I can split the extrution & triangulation process into horizontal and vertical steps ( this is probably what I'll end up doing ), but it does get quite tricky :).
    2. Get an implementation of 3d triangulation ( or write it myself ) , this is not a simple pease of code though, and I have not found a java version that is easy to plug into my code yet. Even with a working 3d triangulation algorithm it has to be tweeked so that it creates triangles in the correct way ( not connect some vertex next to the step to a vertex in the vertical step ).
    BTW What printer did you end up getting ?
    Im looking at the CubeX myself. ( But I'll have to save for it a bit ) . Also interesting was the makemendel.com/3d-printer/rapidbot-mega it has a nice long bed 750x250x200mm might still opt for that..
     
  20. Tugboat

    Tugboat Facilitator RCWC Staff Admiral (Supporter)

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    I've been running my RepRapPro Mendel for about 6 months now, it's quite good. I'm about 2/3 done building a Rostock from scratch. The Rostock has a print volume about 203mmx203mmx700mm and it's 2 to 3 times faster (print speed) than the cartesian coordinate printers due to the much lower moving mass of the printhead and attachments compared to the various cartesian bots' having to move the whole X-axis assembly. It's also self-levelling. I got the E3D hot end for Christmas, which will do most any thermoplastic you throw at it; I'm looking forward to printing in nylon.