IRTF Filter Housing

Images of the filter housing in the IRTF guide camera filter wheel, to assist in the design of a filter mount. The filter wells are 1.99 inches square, 0.3 inches deep at the edges, but only 0.25 inches deep in the middle, due to the concavity of the filter wheel surface.

Click on pictures for larger versions.

Suggested design for "filter tilter". Filter itself is 0.25" thick so will protrude above the filter wheel surface when installed, but there appears to be plenty of clearance. A 3 degree tilt will make thickness of the thick end of the wedge 0.15", sufficiently thin that the filter will be held firmly in the well which is 0.3" deep at the corners. The following diagram shows a 4 degree tilt, not the 3 degree tilt that was finally used.

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