Mounting a guide scope on a Megrez 72

[Rigel]

Hi,

I am a newbie so apologies if I've chosen the wrong section for my question....

I have a Megrez 72 mounted on an HEQ5 Pro. I want to use the scope to image with my Canon 550D. Consequently I'd like to fit a guidescope on the Megrez OR alongside it in some other way.

Can anyone suggest what hardware I need for this? Also, any suggestions on a suitable (cheap) guidescope and CCD for guiding?

Best regards,

Rigel.

[johnrt]

I used a side by side bar when I had a megrez, the scope didn't fit in to the standard size tube rings allowing me to piggy back another scope, so that was the easiest option for me at the time.

The Skywatcher ST80 & QHY5 guider combo is a tried & trusted pairing, it's also a very reasonably priced option. I have never failed to find a guide star with this set up.

[Gonzo]

I have this one http://www.williamoptics.com/accessories/finderBracket_features.php and it works nicely on my Megrez 72.

[K3ny0n]

Im going piggy back route with a Skywatcher guidescope mount. It attaches on to your imaging camera then you attach your guidescope on the mount which would be on top of your imaging camera.

Pricey but so easy to fix. http://www.firstlightoptics.com/guide-cameras/skywatcher-guidescope-mount.html

Rob.

[brantuk]

Imho Johnrt has the preferred solution - I too have a side by side arrangement with ST80 guide scope for my Meg72. It works very well and is straightforward to set up and balance nicely. All the cables you're going to attach tidy away nicely as well if you fix them to the middle of the sbs bar - and you can see what you're doing with them.

If however you want to loose weight - then you could try a "finder/guider" like the mini guider system (link below) or convert a standard finder and make one for yourself (refer to the DIY sections) - many folks have done that.

http://www.altairastro.com/product.php?productid=16468

Nothing wrong with the SW alt/az shoe though - the big benefit of this one is that it makes it very easy to find a guide star - I use it on a larger scope/mount combo. I have all three systems and for the Meg my preference is the sbs bar.

[ollypenrice]

Personally I don't like side by side because it complicates balance and forces an earlier meridian flip, since the extra width collides with the mount earlier. Nor do I see any need for fancy tilt-pan adjusters since you'll always get a guide star with an ST80 and half way decent guide camera. I'd just improvise something rigid to bolt your ST80 down hard onto the top of your imaging scope, or make some brackets to do that. I tend to go for Meccano style solutions. Cheap, cheerful and optimized for the task in hand.

Olly

[K3ny0n]

Personally I don't like side by side because it complicates balance and forces an earlier meridian flip, since the extra width collides with the mount earlier. Nor do I see any need for fancy tilt-pan adjusters since you'll always get a guide star with an ST80 and half way decent guide camera. I'd just improvise something rigid to bolt your ST80 down hard onto the top of your imaging scope, or make some brackets to do that. I tend to go for Meccano style solutions. Cheap, cheerful and optimized for the task in hand.

Olly

Interesting that you say you will always pick up a guide star with the ST80, so it would be pointless to use the guide mount. My current setup has, like you say, a rigid aluminium bar which bolts the two together. I haven't purchased a guide camera as of yet, trying to get the funds together for a new mount and camera and I should be away. Will think again if I really need to have the guidescope mount. 

Thanks Olly.

Rob.

[steppenwolf]

I have successfully used the Altair Astro Finder-Guider on my Megrez 72D - which was itself mounted on the Sky-Watcher GuideScope mount on a side by side mounting alongside another, larger, telescope! Soooo, what would I recommend?

The Altair Astro Finder-Guider and Megrez are a good match leading to a lightweight solution although I don't like the fact that the finderscope (naturally) uses adjustable tube rings and these can lead to differential flexure. However, any guide 'scope has the propensity for causing differential flexure. In an earlier imaging system, I used an ST80 as the guide 'scope piggy-backed on top of the imaging 'scope and this too worked well but, no better than the finder-guider I used later on.

If cost is important, then a decent side by side arrangement is expensive and it too is not immune to differential flexure!

I'd go for the Altair Astro Finder-Guider for now.

Nor do I see any need for fancy tilt-pan adjusters since you'll always get a guide star with an ST80 and half way decent guide camera.

I absolutely agree that there is no need for the SW Alt Az adjuster but the Finder-guider is lighter, therefore, less taxing for the mount and certainly no lack of guide stars available with its wide FOV.