Tired of SCT tube currents, then get rid of the tube

A fair point Bart,
For a six inch scope its hardly worth the effort, one thing I found with the my 12" SCT is that it can take hours (3+ sometimes would you believe!) to cool down after been taken out of the house, this causes an optical defect visible as a plume of warm air rising from the baffle tube and as the tube is sealed it takes longer to reach a stable condition. The effect you get is comet like stars. This is a big draw back in bigger SCTs.

The permanent observatory has solved this problem thankfully as the scope is now always at ambient outside temperature. An open truss system allows the optics to cool down alot faster.

One thing to consider is that a bigger SCT uses a heavier corrector plate, so you would need to be certain that it will not deflect when slewing from one side of the sky to another.

Many of the big RCOS scopes come in a optional truss tube configuration, so it's not really a bad idea once it's done right.

Dear Group,

I have a VERY strong suspicion my beloved AP160 refractor will also remain in tact.

Anthony.

Ah go on Anthony! I have a spare sledge hammer here if you want to prise it open!

Michael,

Thanks for the offer ... which I assume comes after the welder slices the tube into three parts. :lol:

Any idea if we can also perform similar "cosmetic" surgery on my newly arrived AP1200GTO? Dare we try first with Dave McDonald's unit first to get the procedure finetuned? :lol:

Anthony.

Anthony, if you ever need the Apo "modified", just send it on to me and I'll look after it.
What will amaze you is how similar its new look will resemble the skywatcher 70 :lol:

Dare we try first with Dave McDonald's unit first to get the procedure finetuned? :lol:
Anthony.

No problem - I have my angle grinder at the ready. I'll start off with the counterweight shaft. 3 or 4 slices?