Rookie Ship Design Project

Discussion in 'General' started by Kotori87, Mar 28, 2008.

  1. Mike Horne

    Mike Horne Active Member

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    Flush deck: Seems for barrel height issues, to fire over the bow at nearly scale flush is better than the Atlantic (tm) flare :) But since it's got the rise, I'll build it as it is. Seeing as barrel height gets to be contentious... and not to start any arguments, the MABG has language limiting the accumulated depression height, see the armaments section. Might be worth a looksee. Heck, I forgot about it till reminded (embarassment!) I didn't see this get a mention in the latest round of anger, so it might not be known :)


    Mike
     
  2. Mike Horne

    Mike Horne Active Member

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    Motors/speed controllers... I've seen a Scheer at ridiculous speeds on three blades and really cheap but over-volted radio shack motors. Had HU-normous caps to knock down the noise, but the 3 or so volt (by guess) motors were juiced up to 7.2. So, with the small speed control, and differing prop combo's it certainly is a strong possibility. Treaty is I think faster too, and MBG is moving to a different speed chart. The thing to keep in mind is these are smaller boats, and there is going to be a learning curve on propulsion.

    As long as the motor is not way under torqued, to the point that it speeds up the ship as it gains speed and looses resistance to turning (slowly accelerating the ship to beyond speed) I don't think there is too much of a problem.

    Certainly, if the fine folks at BDE or others make a gearbox, or gear combo that can be swapped out, there are even more possiblilites :)


    Mike
     
  3. Kotori87

    Kotori87 Well-Known Member

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    Someone I know is bringing a BC two-output gearbox for me to test-fit in my hull. Hopefully I will find out on Sunday if it works. I am also planning to try geared 280-size motors. Right now, I am only planning to power the inner two shafts, although the outer two will be present and free-spinning.

    Cannonman, I will try to answer your question about the keel. Have you ever seen a table where one leg is shorter than the other three? It has a tendency to rock back and forth between the short leg and the opposite leg. That's pretty much the result I was getting here. I'm guessing that the slot that the keel sits in was too deep for one of the ribs, but looking at it now I can't spot any gaps. I wonder if the subdeck was simply warped a little?

    One other tip. Make the subdeck the same shape and size as the deck. I'd rather sand away bits of subdeck to conform to the shape of the ribs than sand away bits of rib and deck to conform with the shape of the subdeck.
     
  4. webwookie

    webwookie Active Member

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    I added that to the design originally as a surface against which plywood sheeting can be attached in the water channel area, assuming that the joint runs along the centerline of the bottom of the keel. It's not technically necessary and can be omitted; perhaps, though it might make it easier when it comes to sheeting for somebody who doesn't have experience building a wooden hull.
     
  5. Cannonman

    Cannonman Ultimate Hero :P -->> C T D <<--

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    I did dry assemble the stern keel and the ribs that fit to it last night. It did set perfectly flat on the machined surface of my table saw, so it does not appear to be a design issue. A couple of thoughts on this:

    When I assembled mine, I kept the sub deck heavily weighted to the machined table on my table saw through out the assembly process to keep it as flat as possible and "lock" it into the flat shape by adding components. Mine did come out really flat after assembly -- it's possible that warpage was an issue for you.

    The other possibility is that the stern keel has some really small steps in it that may have accidently caught one of the ribs, keeping it from fully seating on the notch in the keel.

    I'll post a couple pics, after work tonight.
     
  6. Kotori87

    Kotori87 Well-Known Member

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    Cannonman, the second possibility you mentioned may have been the issue I encountered. I did not have any issues with warping (except the decks) even though I did not take as many precautions as you did.
     
  7. Cannonman

    Cannonman Ultimate Hero :P -->> C T D <<--

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    Here are the pictures I promised:

    This is the stern Keel dry assembled onto ribs 15-16 with another keel set on the assembly to show the orientation of the "steps":

    [​IMG]


    This is a shot of the keel by itself to more clearly show the "steps" that ribs 15 & 16 assemble next to. Rib 15 goes to the right of the second step from the left, and rib 16 goes to the left of the step to the far left -- if that makes any sense:

    [​IMG]

    Kotori,
    After looking at the pictures, does it seem as if this may have possibly been an issue, or even seem like an issue we may want to address even if it wasn't what caused your problem?? Seems to me that it might be better if the steps were made into notches, to make them grab the assemblers attention more???[?]
     
  8. webwookie

    webwookie Active Member

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    Notches those will definitely become, as soon as I find the time to wrap up the edits that I started (which is now being balanced with the assembly of two destroyers).
     
  9. Cannonman

    Cannonman Ultimate Hero :P -->> C T D <<--

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    It looks like the stern cannon needs to reside between ribs 14 and 15, and from what I've read, the stern cannon is a staple of the fast gun crowd. I'm still looking at possible servos, but it looks like the smallest, most reasonably priced ones that I found are around $10 and would have to go between ribs 15 and 16. I can't find one that is small enough and cost effective enough to be mounted inverted near the rudder post, between ribs 16 and 17.



    I've been looking into this....
    When running one of these motors, it looks like the output shaft is typically something like 2MM in diameter. What is available to couple these to the prop shafts? When running a 280 or 370 sized motor, are they always run through a gear box? Does anyone know with relative certainty which motors, voltage, and props it will take to get to speed for both big and fast gun??



    How long do you guys expect this battery pack to last in battle?? This is what I had hoped to use also, provided that the general consensus is that they will last long enough.

    I am currently prepared to order all of the propulsion components in the next couple of days, I just don't know exactly which motors to try first, and how to connect them to the props.
     
  10. mike5334

    mike5334 Well-Known Member

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    Hey all, how are the builds coming along? :)
     
  11. BoomerBoy17

    BoomerBoy17 Active Member

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    Yea, an update would be nice. Hey Mike, how is Korea, by the way?
     
  12. Mike Horne

    Mike Horne Active Member

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    I think Cannonman has run into some life strife... I'm busy with Baby Godzilla :) There's a big gun potential start up out west... I'm hoping that they will switch to the Emil instead of trying destroyers first... It is a wee bit larger :)


    Mike
     
  13. webwookie

    webwookie Active Member

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    I just did a quick upload of files for the model in 1/96. My computer seems to be having a fit and the software is refusing to generate pdf files so the next best option was to save the plotter output as postscript files. They are located as indicated below:
    Visit this site
    Visit this site
     
  14. Kotori87

    Kotori87 Well-Known Member

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    In the WWCC, I have passed the Emile hull on to someone who will complete the ship. He's an old salt when it comes to cruisers, and has built one Emile Bertin in the past. In fact, we brought out his original custom-machined motor mount from his old Emile, and fit it in the new one. It fits! That's pretty impressive. I will be sure to share any new developments.
     
  15. Cannonman

    Cannonman Ultimate Hero :P -->> C T D <<--

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    Since I have a second, I'll chime in here. As Mike indicated, real life is really rearing it's ugly horns at me right now, so as far as my build goes, it is on hold indefinitly, until I get life back on track. I do have some further progress I can post a picture of, as soon as I get a chance to take one, but I am at the point where I need to purchase the propulsion system, so I have to wait for a finacial opening before I can purchase the required goods and continue the build.

    I'll post a pic as soon as I have a chance.
     
  16. Droidling

    Droidling Member

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    How close are you guys to letting a real rookie try to build this hull? I'm about as green as any rookie could be.

    It sounds like your pretty close to a new rev of the drawings, and I'm really anxious to start. If there is going to be another prototype I'll but a set. If your done laser cutting for now, I can always hand cut my own set. I'll be watching for a drawing update.

    BTW There is a problem with the emile_bertin_foredeck_and_subdeck_1.02.dxf drawing file. I opened it in Autocad 2005 and the layout dosen't show the parts. There isn't any viewport that I can see.
     
  17. Cannonman

    Cannonman Ultimate Hero :P -->> C T D <<--

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    I currently have ACAD 2002 installed, but I'm pretty sure the two are the same... Can you click on the "Model" tab in the lower left corner of the graphics window?? As the file is currently, the "Layout" tab is clicked by default on opening the file.

    As things look right now, due to a job change, I personally will likely be unable to laser cut any more of the kits. There is an outside chance I could get it done, but that is a real outside chance. If there were a sizeable demand I may be able to find someone to cut them.

    I have taken a few pictures of my current progress, as I have time I'll upload them.
     
  18. Droidling

    Droidling Member

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    The parts are drawn in the model view. they are stacked vertically in a SW Isometric view. They just don't show up in the layout. My guess is the changes to the DXF didn't get saved before it was up loaded to the file manager. Did you download your file from the forum, or did Webwookie email it to you? It's not a big deal. I can use the PDF to print plans.

    I was talking to one of the Bitondo bros. Labor Day weekend. He mentioned taking a laser cutting class at the Techshop. Maybe that will work out.

    Terry
     
  19. Cannonman

    Cannonman Ultimate Hero :P -->> C T D <<--

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    Yeah, that Techshop place looks great. I wish there were one near me. Hopefully the Biotondo Bros. can get something going on!! Yes, you are right, the decks do not show up in the layout tab, only the model, I guess I never use the layout. I just seperated them in the model view, and moved them around, and put them on the same plane when I prepared the parts for laser cutting.
     
  20. Kotori87

    Kotori87 Well-Known Member

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    Techshop is a great place. Their laser cutter is a bit finicky about DXF-format stuff, as I have discovered. It can also only cut up to 18"x24" material. It's great for the ribs, keels, etc but it won't handle the subdecks and decks. They do have some excellent equipment, once you get certified on it.