Dan's Safe Kite Control Bar Experiments

I am experimenting with kite control bars for kiteboarding.  Click on images for blow-ups.

• Bar 1: Experimental Quick-release and cleat
• Bar 2: Good Quick-release chicken-loop and cleat
• Bar 3: Adjustable pulley-bar
• Homepage: http://www.zblob.com
  

Bar 1 - 2003/04/15 - "Clunker"

This bar has two experiments: a release-under-load shackle with custom trigger in the chicken loop and a clamcleat for locking the power when unhooked.

Design notes (see diagram):

• Clamcleat: this is attached at about a 90 degree angle to the bullseye, the idea is to rotate the bar when you want to engage it.  It worked ok but required a quick glance to engage it to ensure the rope was in the cleat.
• Part 1: this was machined out of aluminum, it is one main bar plus a small endcap for the tylaska shackle which screws on.
• Part 2: this was machined out of delrin (acetal).  it is a tube with a taper at one end.  a rope goes through it to hold the tie ball on the end.  the tapered design is critical, it allows the tylaska shackle to be released by pulling the tie ball in addition to moving it away or towards the rider.  Make the trigger out of plastic for smoothest action.
  
• Tylaska T5 Shackle (regular bail size): this is the best release-under-load shackle, and its trigger mechanism is the easiest to work with for adding the custom trigger.
• U-Shackle: standard sailing part, must be large enough to not snag the tylaska shackle when released.  Here I used a Wichard 1402 3/16", a smaller U shackle does not release well. Later i switched to a Wichard 1241 5/32" bow shackle since it is smaller but still releases well.

• The Tylaska shackle with custom trigger works really well.
• Chicken loop assembly is a bit clunky and complicated.
• Clamcleat worked well on the beach for launching and landing.  You can't fly hooked in with it, because the rope can pull out of the cleat unexpectedly when you turn the kite.

Bar 2 - 2003/05/01 - "Power Cleat"

• SpinLock Powercleat PX0812: this is a cleating device which locks/unlocks by rotating the bar 30 degrees when the line is tensioned.  It replaces the normal bullseye.  You can reverse the direction of the cleat depending on how you plan to use it.  As shown it is useful for launching and landing the kite depowered, but duplicates the function of the secondary power adjuster.  If you reverse it you can lock any power level on the water so the rear-line load is carried on your harness instead of your arms.
  
• Tylaska shackle with custom trigger (part 2) is unchanged from Bar 1.  See bar 1 design notes.
  
• Both ends of the chicken loop are hooked through the tylaska shackle.  One end has the U-shackle, the other end is tied to the top of the tylaska shackle so it does not go anywhere.
• The Green tie balls are the endpoints for chicken-loop motion.
• The Clamcleat is screwed to a loop of 1-inch webbing.  Use fender washers on the backside.
• It is not shown here, but put a piece of velcro on the rope next to the red ball and stick it onto the bar.  This makes it easy to grab the ball at any time and prevents it from flopping around.
  

• This bar is better than Bar 1 in every way.
• The SpinLock Powercleat works well. I found it easy to keep in either locked or unlocked mode while riding, and it is just as smooth as a basic bullseye when unlocked. It does have problems with sand, after dragging my bar across the beach it jammed up and i had to spend a minute flushing it out. I used the larger powercleat model for now since I was not sure it would be strong enough, but I will test the smaller one in the future.
  
• The chicken loop assembly works well.
• The 'full circle' chicken loop is slightly harder to unhook than the 'half-circle' design in bar 1 because the loop stretches more when you are hooked in. Most riders probably will prefer this.
  
• You MUST TEST the release mechanism, as it is sensitive to the exact parts you have used. Once you find the right parts it will work 100%, but if you for example use the wrong U shackle it will not work well. See Bar 1 notes.  Test the mechanism by hanging your body off it, add additional weights if desired.
  
• The secondary power adjustment shown here is not an original idea, but I showed it since many folks are liking it more than the common commercial designs.

• 3 pulleys are used, here I used Ronstan RF185.
• Pulley 3 has two bolts, locking its angle.  It is mounted as close to the cleat as possible with shims so that the rope is directly in line with the cleat opening.
• Pulley 2 has only one bolt, but 2 bolts may turn out to be better.
• Spinlock Powercleat PX0308.  I used the smaller model this time, it is easier to mount.
• I lathed the wood part from a 2x2 block of white ash I found at home depot (28" table leg: $6.00).  This was convenient since I could leave the bar square at the points where I needed to attach stuff.
• The plastic parts are 1/4" x 2" delrin (acetal).  The winders are 5" long.
  

• Usa a fixed harness line as shown, or you could connect a chicken loop with 2:1 mechanical advantage.
  
• Secondary power adjustment using spinlock cleat mounted on the bar - very convenient and easy!
  
• Pulley-bar setup increases steering response.
• Adjustable pulley-rope increases steering response at low power when kite naturally steers slowly.
• Put the tie-ball on the rope at the maximum-power setting, that way you can instantly go right to maximum power by unlocking the cleat and just letting the rope go.
  

• hmm.