hypothetical GSO truss question

[graham.hobart]

If you had a 10" truss GSO cassegrain and then mounted a refractor which weighed approx. 7kg on the losmandy plate on top, would this cause unforgivable flexure?
I don't know how rigid the CF struts and rings are but would putting another scope on top cause major issues?
Graham

[Paul Haese]

The new truss itself seems quite rigid to me andI would think that a scope on top should not cause a problem internally to the truss system.

[graham.hobart]

Thanks Paul, am considering upping my image scale now I am happy with a wide field refractor.
Umm, now where to go to.....

[graham.hobart]

second question, is there any real advantage to the truss over the 10" solid tube if you are in a protected obs /(apart from looking way cool?)
I mean what do you gain apart from cool down time ?

[Paul Haese]

Graham I think the solid tube carbon version would be better than the metal tube simply for focus stability. I found that the 12 inch was not terribly good for holding focus. Though this might not be the case for the 10".

The truss would cool down very quickly and hold focus well. Though dew on the secondary would need to be handled.

[graham.hobart]

I wonder how you would go balancing a scope like a 110mm refractor on top of the truss? it would seem to put all the weight on the primary end as that is where the d plate is?
I would have thought it would be easier to balance a CF solid tube with the full length D plate.
? any thoughts

[Paul Haese]

You could use another longer D bar and install that instead of the bars on the scope.

Though you could move the main scope a long way up on the saddle.

Not impossible as people have been doing this for year. I would contact Peter Ward. He has a similar configuration.