P3D Project-or-View

[John Fairstein <jfairstein@xxxxxxx>]

Thanks to George for polishing the tarnished image (literally) of the
Projector-or-View. I just cleaned and adjusted the one I bought this
summer. Now it works great. It was a hit at a recent Halloween party
with a 3-D "Scene of Abject Horror" - my wife wrestling a 4-foot
grasshopper.  The kids loved it and the adults were fascinated.

I replaced the missing screen with a sheet of thin window glass backed
with drafting mylar. This material is frosted on one side. It shows good
extinction so I don't believe it depolarizes the image. It would
probably be better to sandwich the mylar between two sheets of glass.

The fan draws air down and out the back, bringing dust with it. This
dust collects on the front surface mirrors and the lenses which severly
degrades the image. The reflecting surface of the mirror is aluminum,
which is soft and subject to scratching. A few scratches won't hurt
since they are not in the image plane, but too many degrade the
contrast. My experience has been to gently clean the mirrors with my
bare fingers in distilled water with some detergent added.Partially
rinse them and allow them to air dry. Another method is to moisten the
edge of lens cleaning tissue with a solvent, then drag the tissue across
the surface of the mirror.

As for the noisy fan, George's cure of removing the support bar sounds
good (no pun intended). Alternately you could replace the bushing in the
bar or ping it in three places with a small drift around the
circumference to tighten it up a little. Perhaps some judiciously placed
rubber washers or grommets will help.


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