RE: [CAD_CAM_EDM_DRO] Re: typical servo speeds

Might I suggest another method? Using crystals mounted opposite one another
with a lever of some sort trapped between the stones, you could excite one
while relaxing the other forcing the lever up or down depending on which of
the stones were excited.

Most ultrasonic applications in the US use 20 or 40 Khz freq, require a ton
of power and get very small but very powerful motion. Detuning to the freq
you want might cut the power requirements to something manageable and using
some sort of ratio multiplier to get the amount of travel.

Something else to consider are the small DC motors in cell phone vibrators.
Run off 1 ½ VDC watch batteries for some while.

R. Wink





_____

From: CAD_CAM_EDM_DRO@yahoogroups.com
[mailto:CAD_CAM_EDM_DRO@yahoogroups.com] On Behalf Of Graham Stabler
Sent: Wednesday, July 18, 2007 5:57 PM
To: CAD_CAM_EDM_DRO@yahoogroups.com
Subject: [CAD_CAM_EDM_DRO] Re: typical servo speeds



--- In HYPERLINK
"mailto:CAD_CAM_EDM_DRO%40yahoogroups.com"CAD_CAM_EDM_-DRO@yahoogroups.-com,
Jon Elson <elson@...> wrote:

>
> Wow, that is still going to be WAY small for the motors I had in
> mind! When you miniaturize this stuff, things like computers,
> batteries, etc. start to be a big problem. Maxon makes some
> REALLY small motors, but they may still be way too big to fit
> INSIDE a hummingbird.

Its certainly no trivial task, standard engineering approaches don't
and haven't cut it. I've been looking from all kinds of angles
including resonant motors that designed to oscillate and may also have
electrical resonance tuned the mechanical. I've also been looking at
auto-resonance which is essentially a form of commutation so that the
power delivered to the motor is optimized and keeps it resonating even
if the natural frequency shifts (it follows it). Insect flight muscle
does this naturally as it contracts after it is stretched and they act
in antagonistic pairs.

> This is where some crafty engineering can go one better than
> nature, we can make springs and cranks that restore more of the
> energy.

I hope so but its so far from straight forward it hurts :) Its easy
to draw various mechanisms but add a bit of play here and there and
all the inertia punishes you big time and your wonderful mechanism
that should produce a figure of 8 produces a mess.

Graham




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