Mounting a guidescope

[Andyfx]

My idea was to use a 9x50 finder as a guide scope and to get myself a small apo refractor such as the equinox 66, however these scopes have no shoe to mount a finder.....

Does anyone know of a solution?

[x6gas]

MMmmm.

Looks like there is a finder shoe in this picture http://www.firstlightoptics.com/equinox/skywatcher-equinox-66-apo-pro-ota.html

Don't have this scope myself, but many scopes have mounting screws. Might be worth firing off a question to FLO...

[Andyfx]

I asked FLO and that model has not come out yet and the existing one doesnt have a shoe or mounting holes either. People must be imaging with small apo's so am curious as to how they have set up.

[JamesF]

You can buy the shoes to mount a finder. If you want to use it as a guide scope then I'd suggest screwing the shoe to the OTA. You may find there is a suitable tapped hole already present.

If you don't want to drill the OTA or focuser then you've probably got to use a small set of guide rings.

James

[Andyfx]

Will have to investigate further, if I buy a new scope i really dont want to be drilling or paying out for expensive guide rings.

[JamesF]

There are probably other ways to skin this particular cat. The finderguider doesn't actually *have* to be attached to the scope at all, as long as they're both mounted firmly. Probably easiest to work it out once you've decided on the scope though.

James

[nmoushon]

I have an equinox 80 and it has a shoe...could always just go up the that instead of the 66.

[Alan_B]

I have an equinox 80 and it has a shoe...could always just go up the that instead of the 66.

Yes - I can confirm that the Equinox 80 has a shoe , It's on the left side see below

[Andyfx]

Cheers but if I was going down that route I'd get a Starwave 80ed.

[JamesF]

Have you decided whether you will mount the new scope using rings or a dovetail? If you use rings then by mounting the finder on a plate and fitting a dovetail to that, you could mount the finder alongside the scope, but completely separate from it?

James

[Andyfx]

Good idea James, i may end up using my St102 as a guidescope instead.

[JamesF]

I imagine that would work as long as the mounting is substantial enough. If you're mounting the ST102 in rings screwed to a dovetailed plate that is held in the saddle then you'd really want to get the two scopes as close as possible together and it may help with rigidity to make up a couple of brackets to join the tops of the rings for each scope together.

The more commonly-used alternative would be to have single plate (mounted on a central dovetail) to which both scopes are fitted. You can buy those, but they're offensively expensive. I'd make one myself or get one made up at a local fabricators. And personally I'd still brace the tops of the rings together.

If you're planning to put this on your EQ5 then I'd check out the weights of the scopes first. If you're getting near the maximum payload of the mount with both scopes then the finder-guider is probably the better option.

James

[Andyfx]

Was thinking of mounting the ST102 to EQ5 as normal, adding a second dovetail to the top of the ST102 tube rings, then mounting the equinox 66 to that.

St102 will guide, Equinox will capture.

[nmoushon]

Sounds like a good plan to me. Like James said only thing is to watch the weight. Especially with adding rings and plates plus camera/guiding equipment could be pushing the limit of the mount.

[JamesF]

Was thinking of mounting the ST102 to EQ5 as normal, adding a second dovetail to the top of the ST102 tube rings, then mounting the equinox 66 to that.

St102 will guide, Equinox will capture.

If the Equinox comes with rings that probably makes sense. I prefer side-by-side myself, but plenty of people like "over-and-under".

James

[Andyfx]

The equinox 66 doesn't have rings it comes with an L bracket on the bottom so should be easy to bolt onto a dovetail, then plonk the whole thing on top of the ST102 tube rings.... Hopefully!