You might want to try find some cast aluminum tool plate at a scrap yard.
This material is cast aluminum with both faces ground flat.  It is used by
machine tool builders and comes in thickness from about 1/2" and up, there
is also metric thickness.  I would check with scrap yards that deal with
machine tool shops and large manufacturers.  I used this material for the
base of my S-G Seismometer.  It cost me about $20 USD for a piece 3/4" x 6"
x 12", this included having it saw cut to size (I think the sheets are 4' x
8' from mill).

Good Luck

Marchal van Lare wrote:

> Hi All,
>
> I think my main frame looks very unstable, so I've decided
> to start 'all over again'.
>
> I'm thinking of making the main frame of one big upright metal
> bar (20-30 centimeters wide), not like the two upright pipes
> from the article. I think this will improve the stability of the
> device.
>
> What do you suggest, a aluminium frame or can any metal be used?
> How big should the base plate be?
>
> Any input will be appreciated,
>
> Best regards,
>
> Marchal van Lare
> -Nieuwvliet, The Netherlands
>
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--
Rex Klopfenstein, Jr.
Bowling Green, OH
rklopfen@.........
www.wcnet.org/~rklopfen



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