DIYbanter - View Single Post

In article ,
says...

And the problem with sand is? Filling with sand probably won't do
much for the stiffness, but would kill the vibrations. It would also
increase the mass and therefore the deflection caused by a bump.

What causes your problem? Stepper motor?

Putting the aluminum under tension will do nothing as far as I know.

Dan

I'm trying to kill a low frequency vibration (think a slow sway back and
forth). I agree that sand will kill the high frequency stuff but it's not going
to help in this situation. I'm having a hard time determining exactly what is
causing this vibration. It's not the mount as I can kill the power and there is
still a slow sway to the mount and it doesn't seem to die out. Either I have
created a really good pendulum or I may be getting a low frequency harmonic
from a highway about a 1/3 of a mile away.

I was thinking about running a tensioning rod from each corner down to the edge
of the concrete pier to triangulate the top and help add a little resistance to
the mount bending in tension.

If I can't solve the problem simply in the next couple of weeks I'll probably
just replace everything with steel. I have the steel but the aluminum came
available at the right price (scrap price) and I didn't have to spend the time
to sandblast and paint it like I will the steel. The only reason I am spending
time with it is that it is so close to working. If I can cut the size or the
error or move the frequency lower so that I can guide it out I'll be happy.

Scott