9-27-09.

  Introducing the new Kinkade "Sure-Glide" dynamic wing lock system! 

This new device augments the standard passive Glide-Loc device allowing you to achieve dihedral lock-ins each and every time on new Kinkade ornithopters. Up to this point, the passive mechanical glide-loc was a "hit or miss" system which often required several attempts before a wing lock-in was acheived.  Lock-in failures were due to the ratchet pin over or under-shooting its proximity to the ratchet pawl when the pilot throttled the motor down.

 This new system still utilizes the standard glide-loc, but dynamically augments it, by bringing the wings into lock mode under pilot command within seconds if the standard glide lock fails to lock in.

It's been said that "simplicity is the hallmark of good engineering". I always try my best to follow this motto. This new system took a lot of thinking and work, but the final result was very simple.  This device basically functions the same as the French "GLDAB" device but does it without the need for custom electronic components or a Hall sensor and therefore is far more economical. This is accomplished by taking advantage of an easily overlooked feature already existing in the typical ESC (electronic speed controller) which is *low voltage cutoff*. If any part of the ESC circuit is opened while under power, the ESC shuts off and stays off even if the circuit is closed again, that is until the ESC is "re-booted" by moving the transmitter throttle stick back to zero.  Because of this, it was possible to design a mechanical system that shuts the motor off right when and where it needs to shut off in order for the mechanical glide-loc to engage.

The existing standard Kinkade mechanical glide-loc was an example of utmost simplicity and light weight,was the first of its kind, and it did the job when the main gear happened to fall into the right sector at down throttle.  But that's always been a random thing because it's very hard for the pilot to control with the throttle stick exactly where the motor stops.  For the glide-loc to lock in, the motor needs to shut down so the main gear and thus the ratchet pin is in the right spot and in the same spot each time. 

The new Sure Glide system does this by means of a trip lever on one main gear that is mechanically timed with the ratchet pin and pawl.  The trip lever has a rear end to it that toggles like a see-saw with each main gear rotation.  The end of the trip lever goes down when the glide-loc ratchet is in its lock-in sector.  There is a normally closed micro switch electrically wired in line with one of the three leads going from the ESC to the motor and this micro switch is attached to a mechanical pivot plate. A five gram sub micro servo mounted near the gearbox ( controlled by 4th channel, rudder trim tab on Tx), rocks this pivot plate, moving the micro switch in or out of range of the trip lever by pilot command. (The micro switch is normally set so it's out of range of the trip lever during powered flight).  It is this "throttle up" pilot command that shuts down the motor quickly, but due to the cycling trip lever, ONLY shuts down the motor when the ratchet pin is in it's lock-in sector.  This results in a glide lock-in virtually every time if done properly.  Operation does requires a simple set of pilot commands that can be done easily within seconds.

 The pilot command sequence to lock in a glide is as follows:

1) Fly to a good altitude, throttle down and watch for a random lock-in
2) If wings lock in, glide. If they do not lock in, activate Sure-Glide...
3) Move rudder trim tab to right, throttle up, motor shuts off, wings lock-in...glide.
4) To resume flapping, move throttle stick back down, move trim tab to left, throttle back up.  That's it!

This new system has been designed into new Kinkade ornithopter kits.

This system can also be made to operate on 3 channels only without the addition of a micro servo and this may be best on smaller models where weight is more critical and the fuselage is shorter.  For three channel operation, a pushrod is run from the tail rocker ( elevator function) up to the micro switch pivot plate.  The set up is made such that the micro switch is normally held out of range of the trip pawl when the tail of the bird is at its normal 25 degree of up pitch.  Full down elevator command is rarely used when flying ornithopters so this command would now be what moves the switch so it activates the Sure Glide lock-in. Just a brief command of "down" elevator coupled with throttle up is all that is needed to lock the wings.

-Sean Kinkade

Kinkade Sure-Glide system copyright 2009.  Patents applied for.