WWII Scharnhorst (IRCWCC)

Discussion in 'Warship Builds' started by Kevin P., Oct 14, 2020.

  1. Anvil_x

    Anvil_x Well-Known Member

    Joined:
    Nov 4, 2017
    Posts:
    1,626
    Location:
    Athens, GA
    Hey Kevin,

    where'd you get the five blade props on your outboards?
     
  2. ZARUBA1987

    ZARUBA1987 Well-Known Member

    Joined:
    Jul 2, 2018
    Posts:
    293
    Location:
    Tarkington Tx
    seriously great idea with the tape.
     
  3. Kevin P.

    Kevin P. Well-Known Member

    Joined:
    Mar 29, 2015
    Posts:
    1,781
    Location:
    Chantilly, VA
    Thanks, I’ve used electrical tape since my first build I think. I don’t recall where I got the props from, some scale model website. They aren’t very good for our ships, the blades have too much cup to them, so they are very directional. They are installed backwards so they will do well in reverse but produce no thrust when slowly rotating forward (hopefully act as drag).
    37D07305-EA86-4403-BBC6-33BF5CA311A6.jpeg
    81F787F3-4AE7-401E-9FA7-96504F491FF7.jpeg
    64356B48-073D-43E7-B00E-000CB045F363.jpeg
    working on rudder mount. Servo needs to go forward of the drop-off
    9E5AE4BF-F0DE-4EEE-83E7-8CE49303A395.jpeg
    Dimension to help with the CAD
    217F468D-4A85-4EEF-8F12-6C67834C3CC1.jpeg
    rudders slightly taller than prop, two pivot points
    CF5F1DE8-BED9-4B71-8090-B2D8D33F4467.jpeg
     
  4. Kevin P.

    Kevin P. Well-Known Member

    Joined:
    Mar 29, 2015
    Posts:
    1,781
    Location:
    Chantilly, VA
    More time spent on rudder mount

    The idea is to have 4x pivot points, so I can vary the balance of the rudders (proximity to the prop) and also the spacing between the rudders. One thing I've found by doing a lot of rudder testing is that it's difficult to predict the optimal combination, which is why I want to test a few set-ups.

    To make this work I'll have half of the mount get fiberglassed into the boat. It will have the 4x rudder post holes per rudder. The top half will be movable and can shift fore to aft. I'll make some studs to hold the halves together by installing screws with the lower half. The upper half will have two sets of receiving holes for the studs. I'll need to plug 1x hole that isn't in use, but the upper half should close up the two other unused hole.

    I played around and found that I could make 1x center gear work for both spacings by using a larger gear on the rudder post that is further from the centerline, without having to draw up another gear diameter. Here is the sketch I ended up with. Needed to use dummy gear between servo gear and rudders due to vertical spacing for servo. Large circles are the pitch diameter of my standard printed rudder gears (20P, 3/8" face). The outer lines show the confines of the hull. I'm planning to have 4x studs, shown by the blue circles.

    RudderMountScharnhorst v5 sketch2.png


    Here's round 1 that I'll print tomorrow

    RudderMountScharnhorst v5.png

    Other side
    RudderMountScharnhorst v5 stbd.png
    Fingers crossed. I tried to visualize how it will work, but need to get it to the boat to be certain, and can always dremel as needed as long as it's close
     
  5. Commodore

    Commodore Well-Known Member

    Joined:
    Aug 8, 2013
    Posts:
    576
    Location:
    Sunny TX
    Tres Fahncee!
     
  6. wfirebaugh

    wfirebaugh Well-Known Member

    Joined:
    Aug 8, 2013
    Posts:
    520
    Location:
    El Paso Texas, USA
    This mite sound like a odd question, but when a ship has 3 props and assuming they all have power to all screws, what is the usual rotation of all 3 props?
     
  7. Kevin P.

    Kevin P. Well-Known Member

    Joined:
    Mar 29, 2015
    Posts:
    1,781
    Location:
    Chantilly, VA
    The outboard ones are counter rotating, the middle one will go one way or the other.

    The prints came out OK today, hole spacing was right on, but will reprint tomorrow with a couple tweaks
     
  8. Kevin P.

    Kevin P. Well-Known Member

    Joined:
    Mar 29, 2015
    Posts:
    1,781
    Location:
    Chantilly, VA
    Got the rudder mount in tonight - definitely the most complex rudder mount I've done. 2nd print with a few tweaks came out great. Gear spacing was perfect, looks like the fore/aft shifting will work
    4AF26564-E69E-4DB9-820E-12F25A86CEAD.jpeg
    printed a top piece to better support the brass tubes since they will be split between the halves
    38FE0C83-7CC0-42E9-82F6-380D04AFB092.jpeg
    drilled first hole from bottom using the mount as a guide to get the hole centered, then drilled from the inside through the mount
    1391984D-8944-4F7E-865E-E42B3C51C534.jpeg
    servo fits great, perfect hole alignment
    0CF7F8DD-5BDF-4F04-BEDA-BFF64774C1D8.jpeg
    Clearance. important to consider subdeck height. Designed to be 5/8 from the deck edge, so 1/4" below subdeck
    ACF7317E-6582-4D49-AC6A-629ED5E04754.jpeg
    I always put a longer rod through to make side the post is vertical
    DA83EDF4-7BBF-440E-A908-DEA0DBE9808B.jpeg
    Epoxy prep
    EA542EB4-1730-4473-A2F9-189F5897C441.jpeg
    7203DA19-B52B-4FB5-A521-28F0ACF74D71.jpeg
    6CB3C334-D2F8-48D7-990A-106F5506DC8B.jpeg
    low profile, filled in around the base to make it solid
    24A2D7A0-319C-4E18-85B6-16A9192E29E0.jpeg
    fiberglass going up sides
    841039C9-AD84-4050-8EC4-27F9B0ECE395.jpeg
    Good grouping on the posts. They'll get cut down just slightly beyond the hull
    342494BF-88C0-4806-8922-36CADD51A610.jpeg
     
    Last edited: Nov 19, 2020
  9. Kevin P.

    Kevin P. Well-Known Member

    Joined:
    Mar 29, 2015
    Posts:
    1,781
    Location:
    Chantilly, VA
    Waterchannel in. Making video so not many pictures
    6CF9BA52-F319-4DF3-B424-83741712C2E8.jpeg
    FEE3BD3E-4929-47A6-8A89-949387C1AE03.jpeg
    Added drain pipes between the voids, 1/4” diameter
    B5F5654B-02C3-477E-B595-0C7A6D60083B.jpeg
     
    Last edited: Nov 22, 2020
  10. Anvil_x

    Anvil_x Well-Known Member

    Joined:
    Nov 4, 2017
    Posts:
    1,626
    Location:
    Athens, GA
    so are you using that break in the water channel foam to act as baffles?
     
  11. Kevin P.

    Kevin P. Well-Known Member

    Joined:
    Mar 29, 2015
    Posts:
    1,781
    Location:
    Chantilly, VA
    The break is for the aft turret, if needed for hose routing. The ultralite around the motor mount will also serve as a baffle for water moving aft, but it's primary purpose is a mounting surface for the solenoids and accumulator tanks. We'll see how it works out, might be too much channeling aft but my goal is to get boats to sink bow first
     
  12. wfirebaugh

    wfirebaugh Well-Known Member

    Joined:
    Aug 8, 2013
    Posts:
    520
    Location:
    El Paso Texas, USA
    Why bow first out of curiosity?
     
  13. Kevin P.

    Kevin P. Well-Known Member

    Joined:
    Mar 29, 2015
    Posts:
    1,781
    Location:
    Chantilly, VA
    Most boats sink stern first, and there is less freeboard in the stern. If the water inside the boat is evenly distributed with the boat stationary, then when running in forward the water will pool in the stern and the boat will sink sooner.

    If more water pools in the bow, the boat will sink level when running forward, and there is more freeboard in the bow so it will stay afloat longer. Most importantly, bow sinks look cooler.

    Like everything, there is a happy medium, as either approach taken to the extreme won’t work out (prop comes out of the water too early)
     
  14. Kevin P.

    Kevin P. Well-Known Member

    Joined:
    Mar 29, 2015
    Posts:
    1,781
    Location:
    Chantilly, VA
    Working on deck now, subdeck cut to size
    A3C9EC1F-8BED-420A-8641-A5B2EFED66F6.jpeg
     
    ZARUBA1987 likes this.
  15. Kevin P.

    Kevin P. Well-Known Member

    Joined:
    Mar 29, 2015
    Posts:
    1,781
    Location:
    Chantilly, VA
    Lots of work today, deck rim and getting rudder post done. Making videos so fewer pictures
    DF9FA26C-BC55-4629-8725-778BA702C441.jpeg
    99619079-9A5A-4964-9ED4-6599B936F35D.jpeg
    Rudder posts had to change to solid tube all way through since I had alignment issues with the split tubes.
    9C72F258-60F2-48BC-B65F-86FE4CA369A3.jpeg
    Now just servo piece moves as needed
    11E93139-0C11-451D-831F-62BCD2FC9E2A.jpeg
    various gear tests, through the 4 rudder post locations
    7DF8E54A-224A-47E2-93D3-AD2EBD189BB2.jpeg
    4F5A463A-1748-4D52-92A3-93CA639DB296.jpeg
    C4DA4A81-1C85-4B6F-9975-6E4957A1D462.jpeg
    97F077CC-6B0B-4FFA-B6F6-125887224169.jpeg
    8A7BB43D-DCBD-42F5-8AAD-8FC7BCA603AB.jpeg
    Showing the removable piece
    111BF920-F881-42B0-93E0-9171B548CEA0.jpeg
    deck pieces
    F135AA5D-EDC5-4C70-ADAE-B6FEC1ED01E8.jpeg
    subdeck in
    C6D446AE-B5B5-4588-AD9C-564942F7E4DA.jpeg
     
    Last edited: Nov 29, 2020
    Evan Fowler, Beaver and ZARUBA1987 like this.
  16. NickMyers

    NickMyers Admin RCWC Staff

    Joined:
    Nov 15, 2007
    Posts:
    4,409
    Location:
    Federal Way, WA
    Bow first sinks also have the happy side effect of not using your rudder and props to find the bottom before the rest of the ship...
     
    Boatmeister likes this.
  17. Kevin P.

    Kevin P. Well-Known Member

    Joined:
    Mar 29, 2015
    Posts:
    1,781
    Location:
    Chantilly, VA
    Deck rim came out good, deck pieces fit pretty good
    9B9058E9-E9FD-499E-811F-62F47BC5EDFF.jpeg
     
  18. Kevin P.

    Kevin P. Well-Known Member

    Joined:
    Mar 29, 2015
    Posts:
    1,781
    Location:
    Chantilly, VA
    Not much work with reserves this weekend, got the barb holes cut tonight, probably will print them up this week, also probably bilge keels. It’s nice how quickly a build goes when only working on one boat
    BC567BC1-4075-4298-8A70-C79FE0BA4C00.jpeg
     
    Renodemona likes this.
  19. Anvil_x

    Anvil_x Well-Known Member

    Joined:
    Nov 4, 2017
    Posts:
    1,626
    Location:
    Athens, GA
    Hey Kevin, I used your electrical tape trick to glass in my new shafts on Texas and ran into a lot of epoxy leaking through the tape. what's the secret here?
     
  20. Kevin P.

    Kevin P. Well-Known Member

    Joined:
    Mar 29, 2015
    Posts:
    1,781
    Location:
    Chantilly, VA
    No secret really. I’ve only had issues with one brand of tape that was very cheap - but it was clear that the tape did not adhere well so a few leaks were expected, and those roles went to the grab bag pile. I found a pretty cheap 3m version that holds great, came in a pack of 5-10 role. I overlap the edges, make sure one piece sticks to the next, and double up a few longer strips over the top. Need to get creative at the end of the shafts with some folded pieces. Nothing crazy though