Pulleys for Cable Steering system

Discussion in 'Boat Design' started by Dhutch, Feb 9, 2012.

  1. Dhutch
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    Dhutch Junior Member

    Yeah, its got to have one there too hasnt it, proberly a little stiffer than what there is there currently. Either than or or non at all and just rely on the ropes give, there shouldnt really be any movement, so the only thing the srping is doing is making it easer to get the tension right without spending ages setting it to the millimeter?

    Daniel
     
  2. whitepointer23

    whitepointer23 Previous Member

    have you thought about changing to hydraulic, there are some reasonable priced kits on the market. you fit and forget, they rarely give any trouble.
     
  3. michael pierzga
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    michael pierzga Senior Member

    What is this SPRING ?...do you mean turnbuckle ? These are the components of a chain cable system
     

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  4. SamSam
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    SamSam Senior Member

    Well, a metal cable might change length with the temperature and require frequent adjustment.
     
  5. hoytedow
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    hoytedow Carbon Based Life Form

    Make a tensioner pulley.
     
  6. SamSam
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    SamSam Senior Member

    He said he has 1 drawbar spring, which I believe is one of these, which can't be stretched out of shape...
    [​IMG]
     
  7. boat fan
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    boat fan Senior Member

  8. michael pierzga
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    michael pierzga Senior Member

    A spring would be stretchy ? Slack in a steering system is not desirable.
     
  9. boat fan
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    boat fan Senior Member

    They work well.
    I had one fitted to an old Hartley power boat in the eighties , never gave trouble .
     
  10. tunnels

    tunnels Previous Member

    Those types of springs are for small boats with outboards bigger boat dont need and not advisable to use . Donot want slack in the cables at all!!
    There is non stretchy cordage thats best !!,its soft and easy to use just use turnbuckle Tensioners with it !! You also need to use large diameter pulleys not small . :p
     
  11. Dhutch
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    Dhutch Junior Member

    It was considered, but we dont want to loose the feedback of a cable and as far as I am aware there are no hydraulic systems that have feedback to them. We boat for the fun of the boating, so feel of the wheel is important

    That looks very like the kit we have currently, which admittedly has done 15 years, but is undersized for a 20ton 58ft boat narrowboat and has never instilled confidence or been overly reliable.
     
  12. Dhutch
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    Dhutch Junior Member

    Thats what we have currently. Its stiff enough that you dont feel it (it doesnt stretch) in normal operation, but when you go hard lock left (to port) and either push it into the end stop or have a lot of power on it then stretches making the off side go slack and hence in current operation, fall off.

    Obviously if the pulleys where all in blocks not in the open it couldnt fall off, and a second spring would keep tension. Any spring would have to be a very stiff one, but maybe its is not required.

    Still 50/50 on rope or cable. Im happy I can get pulleys for either given the links and infomation gained in this thread, which leaved what I can adapt The quadrent to suit and that might be better suited the smaller diameter cable?

    What would a large 180degree quadrent for a rope look like?


    Daniel
     
  13. Dhutch
    Joined: Oct 2008
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    Dhutch Junior Member

    Hi, still working on this but hitting a bit of a stumbling block on what I would need by way of a quadrent if using a polymer rope for the steering system?

    Edson have some nice quadrents but with the 'marine' tag attached, the cost is prohibative, so I would be looking at eather modifying our current quadrent on making a new one in the form of a welded steel fabrication.

    Does anyone have any photos of DIY quadrents they have made or seen?


    Daniel
     
  14. tunnels

    tunnels Previous Member

    Why are you still having to ask ! You have seem whats availible and what they look like so make you own from steel !! And then get it galvanised . The most important thing is to get the diameter right and the attachments for the ropes so you can place a turnbuckle on the ends to tension the rope
    Read what availible and study the pictures !! plus compair what you had and add all the bits of information together and make your own . When i was 15 years old still going to school i bult my own boat and made everything for it from steel and worked out the diameter of the steering shaft pulley and the quadrant dia i needed . To get the right number of turns from straight to full lock . I made plywood pulleys And whan i was satsfied i had it right Then aske a engineer to make the bits !!
    Make a decission that this is what you need and do it !!.
    How will you ever survive at sea if you cant make desissions or ask over the net what should i do ?? Get on with it !!!:confused::
    Gathering to much information makes the job so confussing you will never get any where !So just do it !!
    Make a working model from wood and string exactly what you will need !!
     

  15. Dhutch
    Joined: Oct 2008
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    Dhutch Junior Member

    Well I wouldnt really agree.

    'Stumbling block' proberbly isnt the right term as Im quite sure I have enough information to had a good stab and get something that would work fine, but currently in my lunch hour at work, unableto get in the workshop or on the boat till atleast the weekend after next, I would be interested incase anyone has some photos I could take ideas from before having a crack at making my own.

    - Do people normally run the ropes in two separate grooves, or one wider groove.
    - Is it important to have a curved bottom to the groove to retain the rope, or is a flat bottom with sides ok from a wear point of view.
    - Is there anything else I should be incorporating into the design that I hadnt thought of?

    For instance I hadnt thought of incorporating the turn buckles into the qaudrent. At the moment our cables are just clamped, with 'floating' turnbuckles in the cable runs back the wheel.


    Daniel
     
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