In article <ADDB964B-14F493 at 132.239.144.105>, Nathan Bays
<nbays at jeeves.ucsd.edu> writes
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>>>We just received a de Fonbrune micromanipulator, and it is truly a
>genetic gift. However, a major problem is the fact that the needle
>shakes worse than a wet dog. Does anyone know of any vibration
>dampening apparatus we can use to solve this problem? Any sort of
>platform that can be added to the table top would be especially
>useful.
>Separate micromanipulators and microscopes can have problems in this
area (this is why our workstations have the manipulator mounted directly
on the 'scope).
It is helpful if you mount the 'scope and the manipulator slave unit
(not the joystick part) on a common, massive, rigid base. You might try
a concrete paving stone which you can get cheaply from a builders'
materials suppliers. It will be about 2 inches thick.
Rather than lie the stone directly on the bench, place it on three
compliant, rubbery feet which help to isolate your stone platform from
the bench, stop it rocking and prevent scratching the table. You can buy
fancy, anti-vibration mountings, but try something simple first like
rubber erasers. Trapped, squishy rubber balls (squash balls) sometimes
work and I've seen mounts made by placing four small balls in
tetrahedral pile (like a tetrad) constrained in a suitable ring. Three
of these piles make a good mount. Of course, you don't want your
assembly to get too high !
Make sure that your microscope does not have wobbly rubber feet, if it
does take them off and replace them with something *dead*.
With the de Fonbrune, which is a pneumatic device, the mass of the glass
needle should not be too great: we make needle holders (and disposable
needles) for micromanipulators. Our holders are too heavy for the de
Fonbrune but our needles may be used by sticking them to the end of a
glass rod.
Make sure that there isn't a refrigerator or something vibrating your
workbench and that your manipulator is working properly with no *stick
slip* in the master cylinders.
Keep wet dogs out of the lab.
Hope some of this helps.
Carl Singer
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