• Wide drogue

    lion mclionhead • 10/03/2025 at 05:21 • 0 comments

    What's been working is a heaver gauge shoelace string for lashing it to the truck & a wider drogue.  The heavier gauge string doesn't come undone.  Still a nonzero chance a PLA piece could bolt on & extend above the container.

    It clips on symmetrically.  The drogue drifts left & right with the camber of the road & wind.  Too wide & it goes off the side.  Too narrow & it flips over more.

    It tends to hug the side.  The full 4k camera, drogue, motion control mount burn 500mAh/mile.

  • Introducing the drogue

    lion mclionhead • 09/02/2025 at 08:31 • 0 comments

    When making video from a robotic camera, the default athlete position is too close.

    Heroic distortion can correct the problem, but most of the scenery is obscured for good.  The athlete needs a marker to stay far enough away.

    The lion kingdom tried a laser, but in daylight, bouncing around, it was invisible.  A towed wheel vehicle was the leading contender.  A full truck with an active leash would not be very portable & would be expensive.

    This was a deceptively hard problem.  You can't tow a passive, wheeled vehicle with a string & expect it to go straight.  It'll always oscillate & flip over.  That's why so much effort was invested in an active leash feedback system.  https://hackaday.io/project/188284-smart-leash

    A castered front wheel could go reasonably straight, but not recover from flips.

    Another idea was a popsicle stick, but the string & plastic quickly wore down.  It didn't track straight.  It definitely needed wheels to get the string high enough & reduce wear. 

    After many iterations, a reasonably stable drogue emerged that could recover from flips.  A 1.3m string was a decent length.  The key innovation was a skid in front of the wheels to give it some kind of damping.  A skid behind the wheels was unstable.  The skid has limited life, but it's better than nothing.  

    Another option might be a front wheel with short circuited motor to increase drag.  Then the only wear would be sideways.

    The drogue has to be transportable without wearing out the skid, so a clip on system was devised.

    The mane problem is it's invisible in the dark.  It really needs some kind of lighting, but night movies are the rarest.