Mounting ST80 Guide Scope

[Black Knight]

If by centering a star you mean placing a star in the centre of the screen in PHD (or whatever) for guiding purposes, then you don't need to. The closer to the centre is better, but it is not a requirement. However some people use guidescope rings for those situations where they cannot find a guide star at all. Others prefer fixed tube rings. Personally I've never had a problem finding a suitable guide star with fixed rings, but I've probably been lucky .

Edit: Added a link to some example guidescope rings: http://www.firstlightoptics.com/adm-guidescope-rings-and-systems/adm-guidescope-rings.html

[The Sailor]

My orignal setup as Gina's but since getting the SW 200 it is now side by side with the SW80 on a guidermount and the ED80 now coupled side by side with the 6" SCT on the other mount. Piggyback had issues with movement, minute but enough to cause problems, was not able to fix the issue so went for the setup I have now.

Just remembered, I do beieve the problem stemmed from having three OTA's on the mount, this meant the ED80/SW80 were out on a limb and caused flexing on the piggyback whereas Gina's is central on the mount and more solid.

Jim

[allcart]

The guidescope rings would work when I am imaging through the ED80, but I don't think it will be suitable for use when I piggyback my dslr on top of the guidescope. I may be thinking too far ahead and looking for problems which may not exist as yet. I will find out how it all works when I have the setup running.

[Tinker1947]

I noticed the plastic base was wider than the dovetail. It looks like yours is just sitting on top.

One thing that still puzzles me though, is how to move the ST80 in order to centre a star in my Synscan when I get it. I'm assuming of course that the guidescope will be perfectly aligned with the main scope and will see exactly the same stars. It has been said that sometimes you have to move the guidescope a bit to centre a guidestar.

I run the plastic base through a table-saw to make it narrow enough to inside the top rails...just taking the bottom corners off, this also help it stay straight inline with the dovetail bar.....

[cowasaki]

I bought the brackets for side by side mounting from the same chap as the auto alignment gizmo so it worked out quite well. I haven't used it yet though ! My scope doesn't give me the option to stick it on top. Is the big advantage of piggy backing just that it is cheaper?

[jgs001]

Darren, piggy back is easier to balance, but you tend to need new counter weight as the centre of mass is further out on the axis. I use side by side, once the balancing routine is sorted out, swapping things around is easier, and one of my scopes doesn't allow for piggy back

[Bizibilder]

I have more or less the same as you all do but I have added a SW guidescope mount (the one that adjusts in Alt and Azi) - it cost a few bob but is well worth the money. It is solidly built and, with my set-up, bolts onto a strip of 6mm x 50mm aluminium bar that in turn bolts to the tube rings of my main scope.

[Xplode]

Not an ST80, but it shows how i mounted my INED70 to my MN190.

I hadd to drill 2 new holes in the dovetail bar to mount it.

I choose this method over rings or alt-az guidescoope mount because it's very rigid and lower ventre of gravity than the other options...and it's pretty much free!

[Xplode]

Forgot to upload the picture...

[gcraib]

Nice! Think I would do the same for an imaging set up.

[cowasaki]

Darren, piggy back is easier to balance, but you tend to need new counter weight as the centre of mass is further out on the axis. I use side by side, once the balancing routine is sorted out, swapping things around is easier, and one of my scopes doesn't allow for piggy back

I need to check for how to get email responses to thread! I missed this.

I have extra weights with the mount so that should do it when I get to that point!

I sort of went over the top getting the ST80, brackets and guide scope before even making proper use of the main scope. I swapped some camera equipment for the main scope and having read up on here and elsewhere it seemed like the way to go but I am trying to run before I can crawl with this kit. I've actually had most enjoyment just using the ST80 on a tripod and finding the target manually. I still haven't got to grips with all the messing around calibrating where it is pointing and stuff

[Gonzo]

wrong post, oops

[graemlourens]

Hey guys, a few years later, i'm at the same point

As i don't have access to metal working machines, i'm really looking for the correct items to purchase.

Got an ED80 + ST80.

In addition to this here: http://www.firstlightoptics.com/slt-series/skywatcher-st80-dovetail.html

what do i still need to mount that dovetail onto the ring brackets of the ED80 ?

Any help appreciated

[graemlourens]

Ok got Answer from FLO.

FYI if somebody is looking for the same as i was:

1 x 11 inch http://www.firstlightoptics.com/adm-vixen-type-v-series/adm-vixen-style-universal-dovetail-bars.html

1 (or 2) of these: http://www.firstlightoptics.com/adm-vixen-type-v-series/adm_vdpa_adaptor.html

regards, Graem