Blogs

A 3x2 propeller, another tuning of the PID & azimuth, & a lot of camera flashes got it up to 9 minutes. Previously, it was a 3x3 propeller. The motor stayed just cool enough.

Here, the battery hit 6.6V & started falling over.  Throttle started ramping up at that point.

Overheating still sometimes happens faster & it shows up as a throttle which diverges from battery voltage.

Here, the battery never fell over but was stable at 6.8V.  Throttle ramped up anyways, probably from motor overheating.

Meanwhile, it's a trip into history

as hardware from 2 years ago is recycled

into a new, much lighter, more reliable POV attachment.  The dust shows how long ago M.M. was.

The flight computer had to be rebuilt for the 1st time in 2 years.

Of note is a new etching technology seen on the Goog Tube.

Just float the board upside down on the FeCl.  Surface tension holds it up.  Slide it around to remove air bubbles & let it sit for 30 minutes.  The copper magically falls away as it's etched.  No need for heating, airating, stirring, or splashing FeCl in your eye.

Took 3 years of manual board etching to figure that out.

Magnet wire jumpers.

New & old, with conformal coating.

The 1st Marcy 1 board was made on Aug 25, 2009.

The 2nd Marcy 1 board was made on Dec 30, 2009.

The 1 that consumed most of our time was made on Jan 12, 2010.  So that was a 2 year old board.

So this is our 4th Marcy 1 board.  As much as possible was recycled from the old board.  Working with this ancient hardware of course reminded us of the peak of M.M..  That really feels like the peak.  We don't feel nearly as attached to Her as we did in that time.

Rediscovered the hard way that 32Mhz isn't enough to drive the radio.  It needs the 64Mhz clock.

The full magnetometer is on the wing.  It only does 120 samples/sec.  At the nominal flight speed, that's 20 samples/revolution.

Moved the LED to the wing & did some POV trickery so it could detect attitude during the takeoff.  The POV doesn't seem to interfere with the machine vision.

  Tried using a red LED again for the machine vision, without any luck.  The drop in brightness throws it off even in darkness.  In daylight, the POV overwhelms it.  Anything is going to require white LEDs & differences in luminance.

The original Marcy 1 had the LED on the wing, which may also have improved the coning angle situation.

Disappointing that we never found a use for 3D sonar.  Only a large blimp or a ground vehicle could have used it.  Sonar overall is a mess.  We once envisioned a network of receivers on a ceiling, allowing a UAV to travel anywhere in a building.  It was way too directional & slow.

It could fly a blimp.  There was once a blimp based courier system in an HP building.  They used a robotic blimp to send pieces of paper between cubes.  All we've done is make it cheaper.

Video can now do the job much better.


The long flight times & experience with how long you can expect stable flight got us the 1st flash photos.

Surface mount LEDs would be nice, but we can't afford $20 of shipping for $1 of LEDs.

There was also this video of the very 1st POV flights, with lousier tuning.