Re: Al Extrusion Vibration Damping

--- In CAD_CAM_EDM_DRO@yahoogroups.com, "Roger Hampson"
<r_.hampson@t...> wrote:

> Hi Alex,
>
> The spring would have to be quite stiff or as you say will set up

another

> source of oscillation , but it will Add much needed length to the

resonant

> rod.

The spring would only have to be as stiff as the weight. creating a
mirror image of the ossilation will cancel it out. This technology is
not the same as adding mass. it is dynamic in nature, so the spring
needs to move.

The idea is to elininate a resonnat frequency from being established
at the weakest point by allowing a phase shifted frequency to occur.
kinda like how they earthquake proof buildings.

When I did some machining of condensor tube ends for submarines, the 1
inch wall of the tube was cut OD and ID on the 96 inch vertical boring
machine. when it started to vibrate, it would make a tone you could
hear over the hundred guys welding in the background.

we put those small grey telephone magnets on the side. two or three
would alter the frequency and the chatter would stop. I'm not sure
what the total mass was, but the wall was about 18 inches long, 86
inch in dia, and an inch thick. the end of the condenser coil was at
least 8 inches thick, with hundreds of holes for the tubes. needless
to say, the mass was pretty signigant.

Three magnets that totaled about 8 ounces worked fine.

Dave