What is this second mounting screw for on a CG-5?
Posted 06 November 2013 - 11:00 PM
Posted 06 November 2013 - 11:07 PM
Posted 06 November 2013 - 11:21 PM
There's usually just a tiny bit of 'compression'/movement of the dovetail bar into the saddle when you first tighten the large knob. Tightening the silver knob slightly thereafter sets that silver knob in place. If you were loosen the large knob first, the dovetail/saddle 'springs' back/moves into the pre-stressed silver knob, and it'll dig just a bit more, making it harder to turn. Try it out for yourself.
See, we can even talk about proper techniques in mounting screws on a cloudynight
Posted 06 November 2013 - 11:25 PM
That said I think the practice of using one (or two..) screws to mount a dovetail is Bad Practice. We should all be using clamps.
Even the stock saddle on the CGEM uses a clamp..
Posted 06 November 2013 - 11:31 PM
Posted 08 November 2013 - 01:17 AM
Posted 08 November 2013 - 08:33 AM
That's a safety set screw designed for the type of dovetail almost no one uses anymore.
Posted 08 November 2013 - 11:19 AM
For a refractor of appropriate length for the dovetail's apcing, using rings, there's probably not a better V-series dovetail solution.
Posted 08 November 2013 - 11:27 AM
I think it's a nice, secure dovetail design. Nothing wrong with it at all.
It is fine for use with tube rings, as the tube can be shifted within the rings to achieve balance. The smooth profile plates are required when the plate is directly attached to an OTA (commonly done with an SCT) because in that configuration the plate itself must move within the saddle to achieve balance.