Clutch on the SA dec bracket

[Sylvester111]

This is probably a stupid question, but what does the clutch knob do on the Star Adventurer DEC bracket (not the SA itself)?  I thought it would be to change resistance on the movement of the top rotational plate, but it seems to make no difference. I only know it’s called the clutch knob from the manual.  It’s the one I am pointing to, here:

[NGC 1502]

I’ve just searched and found the manual.  Page 32 of 36 has the diagram of the part in your picture.  I’m puzzled because it basically says what you have, the clutch knob should change resistance on the DEC movement.

Just a possibility- maybe remove the clutch knob and check for debris on the thread?  Or tighten it hard to free it up?

Or is a washer missing so the knob cannot properly clamp the movement?

Hope you sort it, Ed.

[Neil H]

Does it not change resistance to the Dec so easy or less easy to move 

[Tomatobro]

When tightened down it locks the saddle boss to the worm. When loose it allows the saddle boss to rotate. In practice the act of tightening will cause the saddle boss to deflect so the object in view will move. When loose you can grad the scope and position it manually, when tight position by using the black knob.

In the dark I have been known to loosen the centre holding screw and not the larger clutch ring.

[Sylvester111]

Aha!  Now I see!  It’s brand new so must have been a bit stiff when I first loosened it as it didn’t seem to do anything (loosened clutch and it still only turned by the black knob at the back, but with a little encouragement, the top now turns freely with the clutch loose)

Thanks!