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Advanced Reel & Winch Notes

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  • dave santos
    Thanks, Dan l, for the kind word. Here are some further tricks & tips- Reel Shape- A wide reel has a fairly constant mechanical ratio as line is removed or
    Message 1 of 2 , Feb 4, 2010

      Thanks, Dan'l, for the kind word. Here are some further tricks & tips-



      Reel Shape- A wide reel has a fairly constant mechanical ratio as line is removed or added & allows line to dry easier. A narrow reel has a highly variable progressive mechanical ratio such that when all the line is out, & the kite is pulling strongest in wind aloft, the skinny spindle diameter has a high mechanical advantage; but as the line is retracted onto its own backing it runs faster, helping land the kite right to the reel in low surface wind.


      ElectroTethers- A reel for an electrotether needs rotary contacts to convey current past itself. Such reels typically require special insulation & grounding. Winding an electrotether into many coils on a reel will cause well known impedance & magnetic field effects. High voltage, high frequency AC, & ferrous reel construction augment such effects. Inductive & resistive heating  of electrotether on the reel may be a factor. AWE schemes requiring high current VTOL from a loaded reel could be particularly problematic.


      Multi-reels have many variations. 


      A gurdy is a set of reels on one drive shaft with a clutch on each spool. Fishermen use this rig to troll with multilines, selectively reeling any line as needed. 

      Multi-lines can be reeled onto one spool provided a fairlead array orders them, especially combing the lines apart on unreeling.

      A single winch/capstan can serve many lines serially, just as a sailboat might use a single winch for multiple functions. 

      Winching power can migrate between winching stations, just as a sailor carrys around a winch handle from winch to winch. At an AWE field a motor unit might be rolled around to apply winch power at any point.


      Lines rigged with connectors, swivels, & other small tackle can generally be wound onto a reel without problems particularly if the fittings are small & smooth & tension is moderate. Siderigged gear on a line can even be taken up, perhaps onto sidetrack space on the spool. Notches in a spool wall facilitate sidetracking.


      Limit stops & varied sensor targets (magnetic, optical, etc.) on a line enable prcise winch/reel automation. Line length & reel revolution counters provide a more general state picture.


      Extra line is commonly stored on a working reel. As leader sections wear they are trimmed & new line wound out.


      Selecting motive power for winches follows a well established pattern across scale. Without going into explanation, at the tiny scale electrostatic motors are favored, at mini to medium scale human-power or direct electric (gear)motor driving is good, at medium scale pneumatic actuation is practical, & at the largest scale hydraulic power is a sound choice. An electric motor driven compression stage is common for the last two fluid power scales, but direct kite power compression could serve.


      Tensioners of many kinds are a common line handling expedient. Backlash snarls of slack line at the kite reel have been addressed by Peter Lynn (Sr.) with a small water flow in a tube that extrudes line slack. Compressed air may be desirable.


      Hacker Tip- A reel made from a wheel rim can be walled up for high capacity by taking the tire, splitting it around the circumference & mounting the sidewalls crossed inside-out back onto the rim.



      coopip





    • Robert Stuart
      At some point, we will probably notice an effect that surprised (I think) Henry Bessemer, when he hit upon the idea of taking deep ocean soundings using piano
      Message 2 of 2 , Feb 4, 2010
        At some point, we will probably notice an effect that surprised (I think) Henry Bessemer, when he hit upon the idea of taking deep ocean soundings using piano wire instead of rope to speed the process. He got his sounding, and all was going fine until his winding drum imploded. One can reproduce the effect by wrapping a long rubber band around one's finger. For high-altitude work, we will need a slack loop between the winches and the take-up reel.

        Bob Stuart

        ----- Original Message -----
        From: dave santos <santos137@...>
        Date: Thursday, February 4, 2010 2:32 pm
        Subject: [AWECS] Advanced Reel & Winch Notes

        >
        >
        >
        >
        > Thanks, Dan'l, for the kind word. Here are some further tricks &
        > tips-
        >
        >
        >
        >
        > Reel Shape- A wide reel has a fairly constant mechanical ratio as
        > line is removed or added & allows line to dry easier. A narrow reel
        > has a highly variable progressive mechanical ratio such that when
        > all the line is out, & the kite is pulling strongest in wind aloft,
        > the skinny spindle diameter has a high mechanical advantage; but as
        > the line is retracted onto its own backing it runs faster, helping
        > land the kite right to the reel in low surface wind.
        >
        >
        > ElectroTethers- A reel for an electrotether needs rotary contacts
        > to convey current past itself. Such reels typically require special
        > insulation & grounding. Winding an electrotether into many coils on
        > a reel will cause well known impedance & magnetic field effects.
        > High voltage, high frequency AC, & ferrous reel construction
        > augment such effects. Inductive & resistive heating  of
        > electrotether on the reel may be a factor. AWE schemes requiring
        > high current VTOL from a loaded reel could be particularly
        > problematic.
        >
        > Multi-reels have many variations. 
        >
        >
        >
        >
        >
        >
        > A gurdy is a set of reels on one drive shaft with a clutch on each
        > spool. Fishermen use this rig to troll with multilines, selectively
        > reeling any line as needed. 
        >
        > Multi-lines can be reeled onto one spool provided a fairlead array
        > orders them, especially combing the lines apart on unreeling.
        >
        > A single winch/capstan can serve many lines serially, just as a
        > sailboat might use a single winch for multiple functions. 
        >
        > Winching power can migrate between winching stations, just as a
        > sailor carrys around a winch handle from winch to winch. At an AWE
        > field a motor unit might be rolled around to apply winch power at
        > any point.
        >
        >
        >
        >
        >
        >
        >
        >
        >
        > Lines rigged with connectors, swivels, & other small tackle can
        > generally be wound onto a reel without problems particularly if the
        > fittings are small & smooth & tension is moderate. Siderigged gear
        > on a line can even be taken up, perhaps onto sidetrack space on the
        > spool. Notches in a spool wall facilitate sidetracking.
        >
        >
        > Limit stops & varied sensor targets (magnetic, optical, etc.) on a
        > line enable prcise winch/reel automation. Line length & reel
        > revolution counters provide a more general state picture.
        >
        >
        > Extra line is commonly stored on a working reel. As leader sections
        > wear they are trimmed & new line wound out.
        > Selecting motive power for winches follows a well established
        > pattern across scale. Without going into explanation, at the tiny
        > scale electrostatic motors are favored, at mini to medium scale
        > human-power or direct electric (gear)motor driving is good, at
        > medium scale pneumatic actuation is practical, & at the largest
        > scale hydraulic power is a sound choice. An electric motor driven
        > compression stage is common for the last two fluid power scales,
        > but direct kite power compression could serve.
        > Tensioners of many kinds are a common line handling expedient.
        > Backlash snarls of slack line at the kite reel have been addressed
        > by Peter Lynn (Sr.) with a small water flow in a tube that extrudes
        > line slack. Compressed air may be desirable.
        >
        > Hacker Tip- A reel made from a wheel rim can be walled up for high
        > capacity by taking the tire, splitting it around the circumference
        > & mounting the sidewalls crossed inside-out back onto the rim.
        >
        >
        > coopip
        >
        >
        >
        >
        >
        >
        >
        >
        >
        >
        >
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