🚀 go-pugleaf

I did some thrust testing of various electric motors used in RC cars
and planes. Most were pretty good Re: power to weight. 

The big problem I ran into was battery power to weight. The limiting
factor seemed to be there. Adding or deleting motors did not make that much
difference in the thrust budget, as they were offset by the batteries
required by the config.

My base design goal was a creature that would:
     hover itself for 5+ minutes 
     have enough power surplus to manuver during that period
     pickup and carry some small objects.

Based on thrust measurements & available battery data, I could not
get an (electric) critter to hover for 5 min, much less manuver & carry 
things. 1-2 minutes looked possible.

So that left the following options-
     gas bags for lift- (too clumsy & slow)
     dynamic lift- (Not able to hover to pick up objects)
     gas engines- (feasable using the mag clutch methods
                  discussed earlier.)

As the gas engines got into control issues I was not interested
in, I did not persue further. (rpm syncing 3-4 gas engines???)
A single engine approach using a gas engine would make it simpler.
Could you "PWM" the power to the fans using the clutches to vary thrust???
Hmmmmmmm......

WRT mobile robots, hovering ones are neat, but loose much in practicality
because you use nearly all of your energy just hovering. If you could
stay in ground effect, you could reduce that issue. Still ,unless
you are interested in a certain contest, or the nav issues it is not
as practical.

I still like to have "step counting" capability for nav purposes, as
well. (just as a cross reference.)

BTW, I had considered a 4 motor platform so I could use 2 axis of
optical feedback from a pendulum with some existing motor control
chips. I still think it would work.  (replace the pots in a joystick 
with shaft encoders. Hang the batteries from the joystick handle. )

Oh well, my ideas for the hovering robot contest. If you use them, and 
win, remember to mention me in your speech. (and subsequent royalty
payments :-> )

Good luck!


 Alan Barrow  km4ba | I've seen things you people wouldn't believe. Attack
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         km4ba!alan | like tears in rain. Time to die.          Roy Batty