Re: [CAD_CAM_EDM_DRO] Re: typical servo speeds

Graham Stabler wrote:

> --- In CAD_CAM_EDM_DRO@yahoogroups.com, Jon Elson <elson@...> wrote:
>
> That is encouraging Jon.
>
>
>>A real hummingbird, I believe, flaps its wings at about 600 Hz
>>(or am I thinking about a bumblebee?)
>
>
>
> A Bumblebee (I'm currently analyzing microCTscans of a honeybee) flaps
> at around 200hz, a humming bird depending on the species is in the
> 15-30hz range though I'd have to look it up to be sure.

I have actually held a hummingbird in my hand (it was trapped in
a building walkway and needed some guidance to get back into
nature). The numbers you quote sound much more resonable.
I'm looking

> at building something inspired by an insects flight apparatus but more
> on the size scale of a humming bird.

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.
This rig is to allow PIV and

> such analysis in air (other rigs have been scaled up and done in oil).
> Its a tall order as the wings describe a figure of 8 and they have
> controllable stroke reversal for control all at 20hz, the reversals of
> course are at 40hz!
>

I had a dream a long time ago about building a man-carrying
ornithopter and flying it. It had a bunch of levers, almost a
forest of them, to adjust all the different options of the wing
stroke.

> Small flies can go right up to 1000hz
>
> All of the insects are resonant mechanisms meaning that the inertia is
> accounted for with elastic storage, the muscles need only do useful
> work and overcome losses. They can even tweak the resonance by
> stiffening the thorax, its neat stuff.

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

Jon