Carbon MAST tube

Discussion in 'Boatbuilding' started by joe PEREGRINE, Mar 30, 2017.

  1. joe PEREGRINE
    Joined: Mar 2017
    Posts: 1
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: cocoplum beach

    joe PEREGRINE New Member

    GENTLEMEN , LADIES , FIRST POST .PLEASE BEAR WITH ME..
    I HAVE AN IDEA CAN'T FIND ANY PRYOR ENTRIES, DATA, OR INFO RELEVANT.. SO PLEASE FEEL FREE TO CRITIQUE..
    STAYED , MASTHEAD , 6 IN CARBON TUBE , WITH A REMOVABLE MASTHEAD PLATE/CRANE, TO HOLD THREE HALYARDS, SPINN, REACHER, AND JIB.
    FORESTAY ,TWO CAPSHROUDS, AND TWO RUNNING BACKSTAYS...VHF ANTENAE,TRI COLOR,WIND INTRUMENT...
    MAST STEP, LARGE FLANGE , WITH INTERIOR TURNING BLOCKS FOR ABOVE HALYARDS.
    THE TUBE WILL BE 50 FT, AND A 47 FT , 3 TO 1 , PLYWOOD WING MAST ,7 IN X 21IN .WILL ROTATE AROUND TUBE AXIS... ..THE WINGMAST WOULD HAVE ONE MAIN HALYARD AND ONE TOPPING LIFT, WITH EXITS AT 5 FT AND CLUTCHES...
    THINKING OF USING 3 TO 5 BEARING SURFACES, ON BOTH TUBE AND PLYWOOD WING MAST .
    QUESTIONS : WILL CARBON BE A GOOD BEARING SURFACE .?
    Could I simply make a carbon friction BEARING, inner and outer. X5 , MAST head, base , boom point, and two more along axis.??? Lubrication?
    Will a 7 inch TUBE be strong enough, ?????
    Would I need spreaders on wing section.???
    My opinion being an easily rotated , efficient wing section , WITH very little if at all compression loads , very light BUILT and very light OVERALL weight ...
    Your thoughts ,will be apreciated...thank you. ..joe
     
  2. frenette
    Joined: May 2011
    Posts: 21
    Likes: 1, Points: 3, Legacy Rep: 13
    Location: Southern California

    frenette Junior Member

    You didn't give any information about the righting moment of the boat so it's difficult to say anything useful.

    Masthead spreaders are something you put on an existing rig to move a code 0 or a spin from 7/8th to mast head not something you would use as a rig. The spreader angles even on a catamaran don't work. Any reasonable rig design would avoid less 10 degrees angle. Your forces are off the chart.

    A 7" tube would be something more for a 25' mast.

    Carbon wouldn't be my choice for a mast bearing. It doesn't have enough give to it so when the boat's hull flexes and it will you will find tolerances get out of wack so you want something with some give to it.

    Given this I would recommend finding someone to tell you what you need. The net is good for extending your knowledge but you're not there yet and gravity storms can kill people. Please get a professional to help.
     
  3. gonzo
    Joined: Aug 2002
    Posts: 12,408
    Likes: 208, Points: 63, Legacy Rep: 2031
    Location: Milwaukee, WI

    gonzo Senior Member

    The only answer possible, from the engineering perspective, is: it depends. There are so many variables, that nobody can give you a more precise answer. For example, are the bearings roller, ball, straight, taper, etc.? Is the sail structural to the system? Is the mast tapered and then how much and with what curve? Is the mast buried and how much? Easily rotate should be a quantity, ie 50ft lb. Light weight should also be a quantity, ie 378 lb. You should also post all the engineering calculations for the righting moment at different angles,the wind pressure on the sail and any other forces and their vectors.
     
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