Hi

Just curious really, is there a recommended spring tension for the T setting on the focal plane shutter?

I guess it depends partly on the period the shutter will remain open.

When it is on tension setting 1, the curtain moves fairly slowly, which doesn't matter on say a 20 second exposure, but might well do on a 2 second one.

Is there a recommended "T" tension?

Regards,

James

http://www.cameraeccentric.com/html/info/graflex_8.html

There is a recommended spring tension setting for T, and you will find it here on pages 12 and 13: 3 or higher (H on the Super D).

The anniversary service manual I linked in response to your screw size post tells how to set up the Anniversary's focal plane shutter. The tension lock nut is difficult to work with.
There is no set tension for T on any Graflex focal plane shutter.

The operational requirement of any Graflex Focal Plane Shutter is:
1. with the curtain set to O and the tension setting at its lowest setting upon releasing (tripping) the shutter the curtain should fully close in a smooth and continuous motion and lock (wind key will not turn opposite wind arrow) at the end of travel. The top aperture stay for O should be approximately 1/4 inch below the lower edge of the film plane opening.
2. With the tension set to its highest setting the curtain should wind to its smallest aperture without excessive force. The lower stay for the smallest aperture should be approximately 1/4 inch above the top edge of the film plane opening.

If condition 1 does not exist then the base tension is too low or there is a mechanical problem such as dried out lubricant in the curtain roller bushings.
If condition 2 cannot be met the base tension is too high.

Normal base tension for a Speed Graphic is 4 to 6 turns of the tension setting screw.
Normal base tension for a Graflex SLR is 6 to 8 turns of the tension setting screw.