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Aleksei Domanov

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Posts posted by Aleksei Domanov

  1. Opps... Sorry, I missed this post

     

    The problem was with our site (you couldn't use some symbols in both address and name fields), now we fixed it. Thank you for your help to solve this.

     

    Your parcel is shipped out from our country on 3.09 and maybe still on the way as I can't obtain any data from Australian post. Sometimes it takes 7-10days, sometimes 30... Post is unpredictable...

     

    Have you received PSU?

     

    BR,

    Alexey

  2. And I see you have problem with quality of "twist".

    item 4 - It depends on how even strands leave spools.

    My experience on this matter says - you do not need  to brake spools. I made a lot of experiments and lot of versions of spool holders... 

    even in such way :-))

    post-1538-0-42496000-1391759388_thumb.jpg

    post-1538-0-87678300-1391759389_thumb.jpg

     

    and you need to give attention how thread is lay on spool.

     

     

    any questions - you're welcome! you see, I sell version 2.5 and spent several years to make it...

     

     

  3. Dear Michael,

    looks fantastic! But you forgot why you have to use idle gears...

    http://modelshipworld.com/index.php?/topic/5396-domanoff-workshop-planetary-ropewalk/#entry156085

    Item 1

    Because thread is not wire, it's non-deformable. You have to "unwind" each thread while they wind one around another.

     

    Alexey

     

    PS Using pinion to drive solar disk could increase noise dramatically...

  4. First of all: THANK YOU VERY MUCH, BOB, FOR THIS REVIEW !!!

     

    And let me explain some ideas I used in this ropewalk (sorry for my english...).

     

    1. Ratio of "sun" and "moon" gears have a value, "Planet" gears are used only to reverse rotation of "moon" gears and their size may be any. sun:moon = 2:1. Why? Take a look at pic:

     

    post-1538-0-81441400-1391246388_thumb.png

     

    Because thread is not wire, it's non-deformable. You have to "unwind" each thread while they wind one around another. Otherwise there will be tension in final rope which will try to unwind. How many turns? Two for one turn of all threads (look at the picture).

    Now if you put mark on spool holder and make one turn of all system you'll see mark makes two turns. One around "moon" shaft + one around main shaft. That we required.

     

    2. Central core. Thank you, Bob, for good idea! Can I use it in my future machines?

    When do we need central core? Let's take a look at pics:

     

    This is 3-strand rope. You may see - everything is ok, all strands lay in their places. You may need central core (made from very thin wire) if you'd like to "form" rope as you like. Diameter of this core shouldn't be more than 0.155 * R.

     

    post-1538-0-78376800-1391247092.png

     

    This is 4-strand rope. You HAVE TO add central core, otherwise strands will try to be in "center" of the final rope.

     

    post-1538-0-12406300-1391247110.png

     

    3. Quality of the resulting rope.

    Quality depends on angle in which strand goes into resulting rope in "wind point".

    Big angle (red) - tight rope, small (blue) - loose. Should be around 45 degrees (green).

     

    post-1538-0-52571100-1391247869_thumb.png

     

    "Wind point" position depends on takeup block speed.

    BUT. There is one trick...

     

    post-1538-0-81961400-1391248057_thumb.png

     

    Using cross bar (guide bar) you may make this "wind point" at any distance from ropewalk! Look at pic. You may see, 45 degrees angle depends not on position of guide bar but on... hole in guide bar! Even not on hole as it is but on the front point where strand "breaks"...

    You may see on photo - I use different types of guide bar:-)

     

    post-1538-0-31219400-1391249312_thumb.jpg

     

     

    4. Quality twist, without whorls. It depends on how even strands leave spools... If one goes jerky - wind point jumps and final rope has whorls.

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