Recent content by Ron

  1. R

    Knot for joining two lines for an SRT base-tie

    I use the Zeppelin bend with 10 mm EzBend. The 10mm gets really stiff with use but the Zeppelin holds securely. Here's a 450 lb test pull with the Zep, its a bit too long but be sure to watch at the 3:30 to see how easily it comes loose after being pulled to 450 lbs...
  2. R

    FWIW, I have a video series on rope and pulleys...

    Oops, I forgot to update - got two more pulley vids up, segments 16 & 17. These last two deal with climber referenced systems, specifically DdRT and RADS Preface to the RADS http://www.youtube.com/watch?v=76l9KZ6XcME The RADS http://www.youtube.com/watch?v=v1p-xuZNq5g
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    RADS Theoretical Ratio

    [ QUOTE ] ...Description number 1: In RADS, (assuming zero friction and parallel lines, etc., etc.) a climber has a mass of 150# and is suspended in air as a separate person holds the input leg of line. That is: 75# of input force (person holding the input leg with 75# of his or her own...
  4. R

    RADS Theoretical Ratio

    In the top figure of my original sketches, I tried to indicate that the pull line could vary, which obviously it can, and I alluded to that in some of my comments, but most of my comments were based on the understanding that the pull would be vertical - which I did not show in the original...
  5. R

    RADS Theoretical Ratio

    [ QUOTE ] Verrrry good Ron. Almost tempted to start an 'Ask Ron' thread right here. Would be great for us, and you'd probably grow to enjoy it given time. [/ QUOTE ] You may be giving me a more credit than I deserve. Probably would be fun, although I'm not sure I'd last long before I couldn't...
  6. R

    RADS Theoretical Ratio

    Reg, Now that I know what set up you had in mind, here are some things to consider, although I'm not sure how significant they are because often in the field, we have to work with what we have. I've reproduced the configuration here for reference: Keep in mind that this is not stable and will...
  7. R

    RADS Theoretical Ratio

    [ QUOTE ] The first one Ron, thanks. Ive used it to load logs in the past, but with no pulleys. Thanks Dave [/ QUOTE ] Ahhh, I thought the first one was what you described! BTW, did it stay in balance? Of course without the pulleys it's a different situation. Friction would probably help with...
  8. R

    RADS Theoretical Ratio

    [ QUOTE ] [ QUOTE ] However, if this were a parallel rope system as shown in the figure below, it would be a 3:1. [/ QUOTE ] Nice diagrams, Ron! I think the last one is the one Reg is talking about. Why do you describe it as 3:1? It seems to me that if you pull down on the rope the plank...
  9. R

    RADS Theoretical Ratio

    As shown, both of the lower configurations are 3:1 systems. In reality the the lower left would be slightly more efficient because it uses one less pulley. OTOH, no one would connect a stretcher like any of the three diagrams - they're not stable.
  10. R

    RADS Theoretical Ratio

    You're quick! I was working on that as you typed. Check out my modified post. And bear in mind, I'm not sure that's what Reg is meaning, but I think it is. We'll see.
  11. R

    RADS Theoretical Ratio

    Reg, Ahhhh, what I'm reading finally registered. Is this what you have in mind? If so, I can analyze it; but it's complicated because it isn't a parallel rope system and some trig has to be used to calculate the theoretical MA. I just want to be sure I have the right configuration...
  12. R

    RADS Theoretical Ratio

    With no reference to any particular post(s) and just for reference, hopefully this will explain some of those ‘mathy’ and ‘theoretical’ issues that apply, and some things that have been referred to but not stated directly. I’m going to start with a couple of simple definitions and then...
  13. R

    RADS Theoretical Ratio

    [ QUOTE ] ...sometimes its the little things. What is DdRT v DRT? Ron I'm sorry you felt the need to write all that other stuff down in response to my post, you really didn't have to, but I appreciate your time in doing so. [/ QUOTE ] Reg, Hmmm, I'm not sure whether this is good or bad, but...
  14. R

    RADS Theoretical Ratio

    I think adding another term hinders more than helps. We have DRT, DdRT, now hybrid DdRT which is the very same thing as DdRT - that just takes us further away from the issues. E.g. doesn’t a hybrid pulley system have exactly the same issues as a non-hybrid system? Yes, and what’s more, the...
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    RADS Theoretical Ratio

    [ QUOTE ] ...I've always had trouble with the use of the word "you" when refferring to a universal "one" That is one of my big gripes with the english language I think, Or at least my use of it because I say "you" when I'm not really talking about you at all but a more general abstract "one"...
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