JetChopper30 mono deep v hull FRP

Discussion in 'Mono Forum' started by Leo Ho, Oct 1, 2011.

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  1. Oct 1, 2011 #1

    Leo Ho

    Leo Ho

    Leo Ho

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    JetChopper30 mono deep v hull FRP

    Coming soon.

    Design not yet finished. 00002719.jpg 00002721.jpg 00002722.jpg 00002723.jpg
     
    Last edited by a moderator: Oct 7, 2011
  2. Oct 1, 2011 #2

    dwilfong

    dwilfong

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    I am not sure if the ride pad on the keel is legal for racing.

    David
     
  3. Oct 1, 2011 #3

    Leo Ho

    Leo Ho

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    Ref.: ADVANCED R/C BOAT MODELING P.8 BY JOHN FINCH

    http://www.amazon.co...g/dp/0911295216

    Mono hull runs on one continuous wetted surface. Strakes must be ended smoothly. With a RIDE PAD, it is still one continuous wetted surface.

    Likely legal mono class.

    Leo
     
    Last edited by a moderator: Oct 1, 2011
  4. Oct 2, 2011 #4

    Mike Hughes

    Mike Hughes

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    It is not a NAMBA legal mono hull because of the flat keel. Must come to a point.

    Mike
     
  5. Oct 2, 2011 #5

    Leo Ho

    Leo Ho

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    Oh, wonderful. I aware that SD3 and DF33 have similar ride pad. It was ported from 1974 YAMAHA fishing boat.
     
  6. Oct 2, 2011 #6

    ken turmon

    ken turmon

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    Looks like a nice design though, good work
     
  7. Oct 2, 2011 #7

    Leo Ho

    Leo Ho

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    DF33, won the Naviga mono class World Champion for many years, has similar ride pad. Naviga rules might not apply to NAMBA. In the design, I prefer to adopt Naviga rules.

    best regards,

    Leo
     
    Last edited by a moderator: Oct 2, 2011
  8. Oct 4, 2011 #8

    Leo Ho

    Leo Ho

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    A mind suddenly come up. Although www.boatdesign.net suggest that strake should have a small negative angle. The -1 degree angled strakes make tunnels between the strakes and bottom. The boat would be put into the hydro class. Need to change the angle to 0 degree.

    Leo
     
  9. Oct 7, 2011 #9

    Leo Ho

    Leo Ho

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  10. Oct 8, 2011 #10

    tnrcboatracer

    tnrcboatracer

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    Flat pad is legal in IMPBA. Strakes with -1 degree angle also legal, but strakes cannot be lower than keel. A mono will not ride on multiple wetted surfaces if the strake is only -1 degree. Strakes cannot have a squared off rear, they must be faired in if they end before the transom.
     
    Last edited by a moderator: Oct 8, 2011
  11. Oct 9, 2011 #11

    Leo Ho

    Leo Ho

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    Hello Jon,

    http://www.boatdesign.net/ suggest that strake should have a small negative angle. They obey law of physics. RC boat not only obey law of physics but also the NAVIGA rules.

    Never ever thought that a design would be so controversy. Attached file show how the -1 degree strake angle make tunnels at intermediate depth. Not sure if this satisfy the NAVIGA mono class rules. Need more consideration on the strake length and angle.

    Best regards,

    Leo

    [​IMG]
     
    Last edited by a moderator: Oct 9, 2011
  12. Oct 10, 2011 #12

    tnrcboatracer

    tnrcboatracer

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    I understand what the CAD section will show, but in reality, -1 degree is not enough to make multiple planing surfaces. IMPBA does not state that the strakes have to be parallel to the base, only that the hull does not have multiple wetted surfaces at running attitude, the strake are a maximum of 3/4" wide, and 5/16" deep, and that the strakes are not even with the keel.. You can see the IMPBA rule book at IMPBA.net

    I don't know the NAVIGA rules.
     
  13. Oct 11, 2011 #13

    T.S.Davis

    T.S.Davis

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    That flat keel is NAMBA legal. There's even a picture of a flat in the book. As long as it's not more than 15 degrees per side of the keel. What am I missing here?

    We've been running the No Step boats with flat keels like that for a dogs age in FE.
     
  14. Oct 11, 2011 #14

    T.S.Davis

    T.S.Davis

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    Oh, and when can I have one? haha
     
  15. Oct 12, 2011 #15

    LarryConrad

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    Lane one, three boat lengths ahead of you!
    Sweet looking boat.
     
  16. Oct 12, 2011 #16

    Leo Ho

    Leo Ho

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    Thanks to those who participated in this discussion.

    Things becoming more clearer. IMPBA rule book shows a padded v hull.

    The design might not meet the requirement of all boating organizations but hope to meet most of the requirements and are reasonable. Will soon proceed to CNC the prototype. Will post update here.

    Best regards,

    Leo
     
    Last edited by a moderator: Oct 16, 2011
  17. Oct 13, 2011 #17

    Leo Ho

    Leo Ho

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    Hello fellow members,

    These links answer my questions:

    IMPBA OFFICIAL RULE BOOK, March 2006, Page K-5, Technical Standards, Mono Hull Definitions and Restrictions, by IMPBA

    IMPBA OFFICIAL RULE BOOK, March 2006, Page K-6, Technical Standards, Appendix 1 Mono Hulls, by IMPBA

    http://mail.impba.net/images/stories/Rulebook/sec-k.pdf

    NAMBA OFFICIAL RULE BOOK, Section 11, Page 2, Revised 3/15/06, Strake specification by NAMBA

    http://www.namba.com/content/library/rules/namba_rulebook.pdf

    IMPBA RULE BOOK has a picture shown a padded V hull.

    I believe JetChopper30 is legal mono.

    I actually could not found the NAVIGA rule book.

    Things are becoming clearer. Design almost done. Will soon proceed to CNC the prototype.

    Best regards,

    Leo
     
  18. Oct 13, 2011 #18

    Leo Ho

    Leo Ho

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    Thanks to the following individuals, groups, organizations who lead me to many ideas on designing JetChopper30.

    Discussion on lifting strake, angle, width, number, position, spray rail, lifting pad, chine walk by members of http://www.boatdesign.net/

    http://www.boatdesig...akes-23218.html

    GETTING STARTED IN POWERBOATING by Bob Armstrong, Robert J. Armstrong

    http://books.google....0design&f=false

    Chine Walking-Why it happens and how to fix it by Jim Russell

    http://www.aeromarin...HB_Jan2008.html

    Why Does a "Pad" Make a V-Hull Faster? by Jim Russell

    http://www.aeromarin...B_Sept2005.html

    Discussion on hull design by members of OFFSHOREonly

    http://www.offshoreo...ull-design.html

    Strake, Advanced R/C Boat Modeling by John Finch

    http://www.amazon.co...g/dp/0911295216

    Ride Pad, Hull Technology in HydroStream Boats by Virus at HydroStream Boats

    http://www.hydrostre...es/HullTech.htm

    Ride Pad, original YAMAHA design 1974, by Allmand Boats

    http://pangacraft.co.../structure.html

    Ride Pad by CornelP at http://www.rcgroups.com/

    http://static.rcgrou...15-DSCF4625.jpg

    Ride Pad by Ron Frank

    http://www.modelpowe...nt.php?116-hull

    IMPBA OFFICIAL RULE BOOK, March 2006, Page K-5, Technical Standards, Mono Hull Definitions and Restrictions, by IMPBA

    IMPBA OFFICIAL RULE BOOK, March 2006, Page K-6, Technical Standards, Appendix 1 Mono Hulls, by IMPBA

    http://mail.impba.ne...ebook/sec-k.pdf

    NAMBA OFFICIAL RULE BOOK, Section 11, Page 2, Revised 3/15/06, Strake requirement by NAMBA

    NAMBA OFFICIAL RULE BOOK, Section 23, Page 1, Revised 3/15/06, C. 4. Logitudinal bottom strake requirement by NAMBA

    http://www.namba.com...ba_rulebook.pdf

    Best regards,

    Leo
     
    Last edited by a moderator: Oct 14, 2011
  19. Oct 14, 2011 #19

    Leo Ho

    Leo Ho

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    Hello David,

    These links answered your question:

    IMPBA OFFICIAL RULE BOOK, March 2006, Page K-5, Technical Standards, Mono Hull Definitions and Restrictions, by IMPBA

    IMPBA OFFICIAL RULE BOOK, March 2006, Page K-6, Technical Standards, Appendix 1 Mono Hulls, by IMPBA

    http://mail.impba.net/images/stories/Rulebook/sec-k.pdf

    NAMBA OFFICIAL RULE BOOK, Section 11, Page 2, Revised 3/15/06, B. 5. Strake requirement by NAMBA

    NAMBA OFFICIAL RULE BOOK, Section 23, Page 1, Revised 3/15/06, C. 4. Logitudinal bottom strake requirement by NAMBA

    http://www.namba.com/content/library/rules/namba_rulebook.pdf

    Best regards,

    Leo
     
  20. Oct 14, 2011 #20

    Leo Ho

    Leo Ho

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    It was designed to have a big motor compartment to install geared drive, e.g. CMB .21 VAC GEARED DRIVE.

    00002181.jpg 00002182.jpg
     

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