Rookie Ship Design Project

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

  1. Rob Wood

    Rob Wood NAMBA Rep

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    How about some photos?

     
  2. Cannonman

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

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    There are some photos of what I accomplished so far on the previous page in this thread, if that is what you were looking for. [8D]
     
  3. Mike Horne

    Mike Horne Active Member

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    try this link

    http://www.rcnavalcombat.com/FileManager/Storage/633526195878537500.png

    I'm still struggling with the photo add here :)


    Mike
     
  4. Kotori87

    Kotori87 Well-Known Member

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    I am heading off to a build session tomorrow, where I will assemble the Emile Bertin. I will try to take photos.
     
  5. Gascan

    Gascan Active Member

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    A thought: chose a rib in the bow and a rib in the stern and cut out a stand. It would prevent the ship from moving during transport to and from the pond, and could be done with the patterns already made up.
     
  6. Rob Wood

    Rob Wood NAMBA Rep

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    Forgive me for not reading every post in this thread, because I'm sure it's been covered, but I assume the burn marks are from laser cutting, and that that problem has now been solved. Correct?

     
  7. Mike Horne

    Mike Horne Active Member

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    From what I hear, there were a lot of surprises and lessons learned. I think switching from metal to wood caused some unforseen adjustments... other than that, I just don't know :(

    Mike
     
  8. Kotori87

    Kotori87 Well-Known Member

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    Yes, the burn marks are from laser cutting. I don't know if that issue has been fixed yet, because Cannonman has not done a second production run yet. We're still identifying all the bugs and working them out before making a second attempt.
     
  9. Kotori87

    Kotori87 Well-Known Member

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    I have *mostly* assembled the kit that Cannonman sent me, and I will have the rest of the wood attached by the next battle. I will bring it along to show off. After doing the assembly, though, I do have a few suggestions to improve the kit for the next run. Starting at the front and working my way back, they are:

    1) bow keel and bow rib: The forwardmost rib, which helps form the shape of the impenetrable bow, is not clearly positioned on the hull. If you could notch it like the other ribs, so it has a clear place, that would be helpful. The other issue is that the keel doesn't include the profile of the bow. It's only the bottom, and that makes it hard to visualize what shape the bow is supposed to be. I will be making the part next Saturday, but for future kits that would be useful to include.

    2) inside profile of the subdecks: The inside profile of the subdecks needs to be wider. The precise reason is currently classified, but the inside profile needs to be at least 2.5 inches wide, preferably 2.75 inches or more.

    3) laser burn marks: I sincerely hope that the next batch of kits doesn't have the burn marks that this one does. I made the stupid mistake of assembling the kit with the subdecks burn-side-up, and didn't realize my mistake until I was almost done assembling stuff. I'm still kicking myself over this one, and I hope nobody else has to share my suffering.

    4) bilge keels: I have two comments about the bilge keels. First, they're asymmetric but they fit into the prepared slots both the right way and the wrong way. I had to check the CAD model to get them correct. Second, they seem a little on the small side. If I plank the boat, they will almost completely disappear. Their current size also doesn't provide much benefit, stability-wise. Consider adding 1/8" to 1/4" to the bilge keels. It may not be perfectly scale, but a little bit there will make a big difference in performance and appearance.

    5) Keel Skeg: On my kit, the keel skeg in the back of the boat didn't sit quite right in the ribs. In some ribs it was all the way down, but in others it had a small gap. It could rock back and forth by up to 1/8". I took my best guess and it turned out good, but it may be worth looking at this to figure out what I was encountering and how to prevent it next time.

    6) As Cannonman already mentioned, the whole back part with the rudder-post-hole, aftmost keel, and aftmost rib, is pretty flimsy. I also found that mine didn't quite line up. You may consider notching the subdeck so the keel can slot in, and guarantee it fits properly. As it was, I guessed as to the correct position and think I got it right.

    7) weapons locations: I am interested in where the primary turrets and torpedoes are located. Could someone please tell me which ribs those components are located between, or their distance from the bow or stern, in inches?

    Overall this was a VERY awesome kit. I put the whole thing together in less than an hour. It's lightweight, sturdy, and very square. It's also very intuitively put together. If I were to build this ship from scratch, it would have taken me a week of calculating and drawing, plus another two or three days of careful cutting to get a hull this nice. I also test-fitted a 4-oz CO2 bottle, and it fit quite nicely. I will need to spend more time working on a viable layout for the rest of the gear, though. I will say for certain that some rookie is going to be very happy when he gets this baby.
     
  10. Kotori87

    Kotori87 Well-Known Member

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    I've been looking into possible layouts. I've been test-fitting various components including weapons, a 3.5-oz CO2 bottle, and several different servos. Here's what I'm thinking for the layout:

    steering: I was quite pleased to find that a standard servo fits inside the hull between frames 14 and 15. You could go with a micro-sized servo and fit it between frames 15 and 16 (closer to the rudder), but standard servos are half the price of micro-sized servos, and I'm on a budget.

    propulsion: I plan to drive only two shafts. I will install all four shafts and props, but only the inner two will be powered. Motor-wise, I am considering two options. The first is a pair of geared 280-size motors. These are quite powerful, and I have no doubt that they will get the ship up to speed. They may even be capable of Fast-Gun speed. The other option I am considering is a geared 400-size motor with two output shafts. I believe Tugboat has info on these? Whichever I choose, they will be going in between ribs 12 and 13.

    Armament: since I am doing Big Gun, I will be using torpedoes. Further information on the armament is currently classified. The torpedoes will go in the middle of the ship, so I am currently keeping ribs 8 through 12 clear.

    Gas: The Emile Bertin can easily fit a 3.5 or 4-oz CO2 bottle. I am hoping that I can get away with 16-gram disposable cartridges, but I'm also prepared in case it doesn't work. either way, the CO2 system goes in right around the step, either just before or just after. If it's a 16-gram, then it goes in front of the step. If it's a 3.5 or 4-oz, then it goes between ribs 5 and 8.

    Batteries: I am planning to use a single 6-cell sub-C NiMH pack with 3000mAh to 3800mAh. If I'm under-speed, I can switch out for a 7-cell or 8-cell battery. I've got several choices for location, depending on the CO2 setup. If I use a 16-gram cartridge, then I can put the battery between ribs 5 and 8. If it's a 3.5 or 4-oz bottle, then the battery goes immediately forward of the bottle.

    Has anybody else been thinking about layout?
     
  11. Cannonman

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

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    Yes, the burn marks are a side effect of the laser, and to some degree, our attempt to control it. When we cut the 1/4" sheet, we had a problem with severe burning where the laser beam would cut through the wood in an area where the bed contacted the wood. The worst catalyst to this problem is that the slag from our production metal cutting sticks to the bed and is then heated as the laser comes across it, and in return, it gets so hot that it burns away some thickness of the wood. To combat this we tried using some of the scraps of the already cut sheets to keep the 1/8" material off of the bed, since if it burned like the 1/4" did, it would reduce the thickness possibly enough to render the piece useless. Unfortunately, the side effect of this was that anywhere the two pieces of wood overlapped where a cut was being made, severe discoloration (black burnt look) of the surface of the wood occurred. We have discussed several different solutions to the problem, and intend to test each to see which gives us the best quality before we run anymore kits.

    As far as the burning on the 1/8" goes -- hit it with 180 grit on a palm sander, it comes off incredibly easily. I'm sorry I forgot to forewarn of this -- I actually meant to sand the pieces before I sent them out, and forgot. I also assembled mine with the burnt sides up on the rear deck, away from the ribs, and I also was angry with myself for doing so until I hit it with the palm sander and it came off so easily. Take a look at my pics. In a couple, you can see the bottom of the forecastle deck is burnt, but neither side of the rear deck is -- I had already sanded it, and it was the worst of the bunch.

    The black on the sides of the ribs may be able to be reduced with some experimentation, but I don't think it can be completely eliminated, but the burning on the surfaces should be able to be reduced to the point that it is negligible.

    Please keep in mind, that to some degree, some of the problems with precise fitting of some of the smaller 1/8" thick pieces are due to the profiles being accidently cut too small, and I was going to throw them all away, and try again at some point. Now I'm glad you guys talked me into trying to assemble them, instead of tossing them!! [:D]
     
  12. Kotori87

    Kotori87 Well-Known Member

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    Cannonman, I will hit the hull with sandpaper and see what that does. I have high hopes.

    I've been thinking about the construction some more, and I thought of another way to improve version 2. I realized that the bottom edge of the penetrable area is not defined, and it may prove helpful to do so. My idea is to put a 1/8"x1/4" (or similar) wooden plank along the bottom of the penetrable, along the full length of the ship. The plank should be recessed into the wood in a similar fashion to the bilge keels, so that the underside of the boat can be easily wrapped in thin plywood.
     
  13. Cannonman

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

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    I was kind of thinking something along those lines also. In an earlier post Webwookie said that the bilge keels defined tha seperation point between penetrable and non penatrable, but it is still hard to discern where that is beyond the ends of the bilge keels, in particular, near the stern where the 45 or 60 degree rule would come in to play. I would like to see some "stringers" like you are talking about, to give a little more area to attach balsa, to define the penetrable area in an un mistakeable way, and to tie the ribs together a little more.
     
  14. webwookie

    webwookie Active Member

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    There are a lot of very good ideas for revisions here, certainly enough to keep me busy for quite a while once I have a chance to really dive into it. Now that I've had a chance to play around with modeling the ship kits in CAD for a bit, I'm wondering if the forward main deck should be revised to either be flat or have a constant angle (eliminate the curvature resulting from modeling-in the raking of the bow). For the edge of the impenetrable area, I'm thinking that adding a notch in the ribs for a 1/8"x1/8" strip would be the most feasible; I do foresee some potential for that to cause some deformation of the keel (possibly causing the hull to cup downward?) though if something other than balsa should be used and if I don't modify the keel somewhat.
    The next revision of the templates will have turret centers indicated. I still need to complete the superstructure however before I post any data for anything above the main deck. Also, I'm definitely adding notches to the subdeck where they have previously been absent; after finishing out the Orfey class hull from my previous data and going to build it, the notches for the ends of the keel have shown themselves to be priceless.
     
  15. Kotori87

    Kotori87 Well-Known Member

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    Webwookie, you are correct in that adding stringers to define the bottom of the penetrable area may cause warping. But I don't think it's a serious probability, because the stringers only need to be harder than the balsa. We could use balsa, or any of several other soft, flexible woods. The rigidity of the hull already is incredible, so I don't think warping is going to be much of an issue anyway. I would recommend using a stringer that's wider than 1/8" though, so you can attach both the wrapped underside of the ship and the balsa skin to the stringer.

    Has anybody else been thinking about running gear, armament, and other hardware?
     
  16. Mike Horne

    Mike Horne Active Member

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    There was a much talked about cannon design from Jason Annen for the Mogador about 2002, 2003 or so... I think it was a quad tray arrangement. I may have a chance to see a surviving cannon sometime soon.

    If there are torpedoes, I'm thinking on the spring design that many have been working on here and there.

    Otherwise, I'm thinking a micro servo for the rudder, and those really small speed controllers found by Knight.

    If there is enough weight reserve, I was thinking of putting the receiver in the super, enclosed in good fiberglass structure.

    Batteries... I'm thinking loose packs of the high capacity batteries mentioned by Rob Wood.

    Mike
     
  17. Cannonman

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

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    Hey guys -- really good discussion going on right now!! Gotta like it when a plan starts to come together.

    Something for everyone to keep in the back of their minds as far as the motors go:

    Would it be possible to get the ship to speed for both fast and big gun using the same motors??? Reason I ask is that if they are the same, it simplifies mounting, and we could hopefully incorporate some type of motor mounts so there is no guesswork involved to get them mounted. Then maybe the speed could be brought down to big gun speed by using smaller props, or lower voltage or something of the like.

    What do you guys think?? Just wanted to throw this out there.
     
  18. Cannonman

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

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    Kotori,
    Did you have a problem with the keel fitting in particular ribs?? I did not have any issues with the kit I assembled, and I'm wondering if the thickness of the ply varied enough to cause it to fit too tightly in some of the slots??? I should have more ribs and another keel, I'll dry assemble another set and see if problems arise.

    ALL:

    I'm trying to keep up on the replies to posts, but it's a lot to digest, so I apoligize if I run a little slow, or have to break up responses into smaller posts to try to work around my family time!![:)]
     
  19. Cannonman

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

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    I just noticed something--

    It looks like on an earlier version of the PDF files there is a statement: "Also required 20.375 x .125 x .125 (1) pc."

    I did not see this on the later versions. Did I miss it??

    From the description, and looking at the hull, it looks like this piece was intended to run centered between the dual keels, between ribs 6-13 as a center keel. If we add this piece, it seems as if it would almost have to be made from something strong and stable, since it's such a small piece (1/8 square x 20-3/8" long) Possibly some type of hard wood or possibly bass wood??

    Webwookie, any insight on this??
     
  20. Cannonman

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

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    The best I can measure from the DXF files, the rise is somewhere around .075"?? If that is all the more the rise is, I don't think it makes any difference if it is a constant angle, flat, or curved. It can probably be whichever one everyone thinks would be easiest to assemble. I've curved mine, angled mine, and even had it going a little downhill, and visually it is very hard to tell, at least with the hull at it's current level of completion. It may be more noticable once it is skinned though.