Re: vibration damping materials

Hi Terry,
I once saw a demonstration with two hollow iron castings for a
heavy CNC lathe. One was left hollow. If you hit it with a several
pound sledge hammer, the hammer bounced back alot. Next to it was
one simply filled with sand. When you hit it, the hammer rebounded
almost none at all; the relatively LOOSE sand inside abosrbed almost
all of the shock (similar to a dead-blow hammer). The sand doesn't
take place of a decent rigid low-center-of-gravity base which you
still need, but can be in addition to it to help absorb shock. I
once built a small base with concrete and rebar. I also
added 'admix', an acrylic supplement normally added to thin-set
mortar for tile work that gives it much better resilience. If you
make your own base of conrete, you might want to have rebar, and use
the 'admix' (which is available as Home Depot), also use a concrete
vibrator to remove air pocket in the concrete while still wet.

Jeff
http://www.xylotex.com

--- In CAD_CAM_EDM_DRO@yahoogroups.com, "machineman_55
<explorer@b...>" <explorer@b...> wrote:

> Hi, my name is Terry. I am looking at designing a mill based

on

> welded steel pieces to make up the base and collum. I will need

some

> form of material to put in this frame to take care of

vibration.Does

> anyone know what I can use and where to get it. Your help would be
> most appreciated.
> Thank you
> Terry