ST 120 on the AZ3?

[Smeet]

Hi, I know there has been posts about this sort of thing before.... But, I could nt find a definitive answer.

I want the ST120 and can only afford it on the az3 mount, is it an issue? I'm not someone who is planning on spending hour after hour, night after night using it, but also don't want something that is no good. If that's the case maybe I should get the 102? If anyone had the st120 on the az3 I would much appreciate your views

many thanks

Smeet

[oobydooby]

There has been a similar enquiry on this forum, albeit a few years ago, which does go into some detail.

Hope it helps See here

topic 176387-portability counts

Oobydooby

[Peter Drew]

Despite probably being well over the limit for an AZ3 I would still go for the 120 bundle as the AZ3 is a "steal" at £40. If you can find a way of attaching a counterweight to the front of the mount to offset the imbalance at high elevations then the manual slow motions cope well. I successfully mounted a binocular made from two ST102 OTA's which weighed more than a single 102 on a counterweighted AZ3.  

[spaceboy]

Not often I would disagree with Peter but on this occasion I'd have to say steer clear of the AZ3 120ST. I know there are mods to help these mounts and mine was fine for solar observing with a 102ST but it could be a right chore using it at night when your picking out multiple targets. I'd imagine this would only become worse with a much larger 120ST. I ended up getting an AZ4 which I have never for one moment regretted. If your on a budget stick to buying used.

[happy-kat]

Mount modifications like this. I did something similar to my Az3 though mine carries and ST80.

link here

[Peter Drew]

16 hours ago, spaceboy said:

Not often I would disagree with Peter but on this occasion I'd have to say steer clear of the AZ3 120ST. I know there are mods to help these mounts and mine was fine for solar observing with a 102ST but it could be a right chore using it at night when your picking out multiple targets. I'd imagine this would only become worse with a much larger 120ST. I ended up getting an AZ4 which I have never for one moment regretted. If your on a budget stick to buying used.

Fair comment but this was my rationale. The OP suggested that he could afford the 120 on an AZ3 and the 120 is ultimately a better option than a 102 specially at a later date on a more suitable mount, the AZ3 could be then sold on at little or no cost. As far as the AZ4 is concerned I personally would not swap the AZ3 with it's slow motion controls plus a counterweight, for an AZ4 without.

[Davesellars]

Since it's only £40 more for the bundle over the OTA only I'd go for that and use it for the time being.  BtW, The ST120 is rock solid on the AZ4 certainly no need for slow motion controls imho.  They seem to come up reasonably often used for a good price as well, recommend with the steel tripod.

For DSOs aperture is important since you're not generally using high power the stability isn't critical.  Upgrade when you can.

[paulastro]

I have to say, having tried both, I much prefer an AZ4 to an AZ3 - counterweighted or otherwise.  My AZ4 is much smoother to move around than any AZ3 I've used, I find the latter rather stiff and unsure in comparison.  My AZ4 copes very well with my Equinox 120ED which is much heavier and longer than a ST120.  I also find the slow motions of the AZ3 rather inadequate and would much prefer a much smoother operating AZ4 without slow motions.  In fact I find the AZ4 a better proposition than the AZ5, never mind the AZ3.

Though the ST120 is smaller than my Equinox 120ED, and would not be such a burden to an AZ3, I'd s still prefer the rather slick smoothness of the AZ4 in comparison. If slow motions are essential, I'd want at least an AZ5 which makes the proposition rather expensive.

[John]

I tend to agree with Peter, the AZ-3 is not perfect by any means but it will do a reasonable job with some tuning. Here is someone using the much longer refractor on the AZ-3 with a simple modification:

https://www.astromart.com/reviews/article.asp?article_id=955

Here is a review of the 120 F/5 on the AZ-3:

https://www.astromart.com/reviews/article.asp?article_id=288

And finally someone using a 120mm F/8.3 on the AZ-3:

https://www.cloudynights.com/articles/cat/user-reviews/telescopes/120mm-130mm-refractors/orion’s-120mm-f8-on-an-az-3-alta-azimuth-mount-r897

For a couple of years I had my Vixen ED102 F/6.5 on an AZ-3 mount and also from time to time a TAL 100 F/10 refractor. With some adjustments these can be workable solutions although, in due course, moving to an AZ-4 or a Giro type mount will become desireable if you do higher power observing.

If the budget is tight the AZ-3 will get you observing with an ST120 and with the darker nights now here that has got be be good

 

[paulastro]

Smeet, it's clear there are various views on this.  Is there anywhere you can go to try out both mounts?  It's a shame you're so far from The Astronony Centre, you could try out a variety of telescopes on Peter's AZ3 and I'd be happy to bring my AZ4 along .

[John]

I'm not sure there are varying views on this. I don't think there is any doubt that the AZ-4 would be a better mount and trying the two side by side would demonstrate that. I think the point is that the AZ-3 / ST120 combo is workable and, crucially, within the OP's budget so it's attainable.

 

[paulastro]

27 minutes ago, John said:

I'm not sure there are varying views on this. I don't think there is any doubt that the AZ-4 would be a better mount and trying the two side by side would demonstrate that. I think the point is that the AZ-3 / ST120 combo is workable and, crucially, within the OP's budget so it's attainable.

 

Isn't the fact that I said there are varying views on this, and you have just said 'Im not sure there are varying views on this' proof that there are indeed varying views on this John! ?!? 

[John]

5 minutes ago, paulastro said:

Isn't the fact that I said there are varying views on this, and you have just said 'Im not sure there are varying views on this' proof that there are indeed varying views on this John! ?!? 

We all seem to agree that the AZ-4 is a better option. We all have some reservations about the AZ-3, especially as a long term option. Nobody is saying (unless I've missed it) that the AZ-3 / ST120 is simply unworkable.

The AZ-3 gets Smeet up and running with the scope that he/she wants to get. A better mount can be considered in due course but meanwhile, astronomy can be done !!! 

 

 

[davyludo]

For what it's worth... I got the ST102 without the AZ3 mount (I know you're looking at the ST120). In the end I regreted it and bought a second hand AZ3 from astroboot. I think it ended up costing me £10 more than if I'd just got the bundle. 

I've tinkered with the AZ3 a bit and yeah it has it's issues...but it's still had a fair bit of use. It has been stripped and regreased, which resulted in the alt slipping. This is because it's a nyloc nut that holds alt in place and I'd knackered the nylon bit. Replaced with a new one and it's never been better.

Basically my point is, knowing what I know now and having tried he AZ3, AZ4 and AZ5.... I'd still get the bundle. If it's only £40 more, the AZ3 is worth that easily.

Yes there are better mounts, but it's better than not having a mount. Even if you get an AZ4 at a later date, you might still find use for the AZ3. For example, I couldn't take my AZ4 on a family holiday due to limited space in the car (there was a wheelchair that swallowed more space than expected). My AZ3 fitted nicely into a little gap I had left. It was perfect for a couple of shorter sessions while I was away.

Now the AZ3 lives in my flat on my first scope (76mm newt) so it can be used for quick looks when the sky is clear. My other scopes and mounts live up at my mum's because she has less light pollution. So they get used for proper sessions at the weekends. As you can see....even with better mounts, it still gets used.

One thing to look at - I don't think the AZ3 bundle comes with a dovetail, the rings bolt straight onto the mount head. So if you were to get a different mount in the future you'd need to pick up a dovetail.

[Smeet]

Thank you all so much for your responses, they are all so interesting and have given me a lot to think about.

this really is a great site and hosts a wonderful set of people full of great ideas, enthusiasm and passion.

smeet