Sky-Watcher Star Discovery compared to AZGTi mount.

[Grump Martian]

I am interested to know how these two mounts compare. Both have 5kgs payloads. But the mounts look quite different. Do they both have the same gear sets, motors & bearings? One review of the Sky-Watcher Star Discovery the Orion branded version in the USA says that it would handle 6.5 kgs.

Edited May 15, 2023 by Grump Martian
Added content

[Zermelo]

I'm not aware of anyone on here who has both, but I have the Star Discovery and, quite recently, the AZ-GTiX.

I've not dabbled with the innards of either mount yet, though there are threads where these have been discussed, for the Star Discovery:
https://stargazerslounge.com/topic/285612-star-discovery-clutch-adjustment
https://stargazerslounge.com/topic/323361-skywatcher-star-discovery-azimuth-slop

and you may already be aware of the long thread dedicated to the AZ-GTi:
https://stargazerslounge.com/topic/387014-skywatcher-az-gti-mount-owners-thread

Yes, the nominal capacity for both mounts is 5kg, though the usual caveats apply: that performance will degrade gradually with increasing payload, that it depends on the length of the OTA as well as the weight, and that it depends whether you're using it for visual or imaging.

I regularly pushed the limit on my Star Discovery, though not as far as 6.5kg. The mount has never given up on me, but it's hard to tell if the weight is having any effect. I've had some excellent sessions, in terms of goto and tracking accuracy, but it has also  been quite inconsistent. I've never been sure whether that's down to inherent mechanics, or to my pushing the limits, or to the Synscan software and the mount's motor board firmware (hence my attempts to monitor the performance). I'm hoping to get a comparison with the AZ-GTiX, which uses the same control software, but different firmware and a slightly greater capacity.

Yes, the Star Discovery is marketed as the Orion Star Seeker IV in the U.S., and it does seem that the payload limit is sometimes quoted differently in different markets. To be honest, I've always thought that the single-arm mounts look a bit awkward, and the ability of the AZ-GTiX (and the AZ-GTi, with the counterweight mod) to balance the load seems preferable.

This site is an interesting account of one person's experiences of the Star Discovery with different OTAs, and in particular their deliberate attempts to run it beyond the nominal capacity.

Apart from any variation in mechanics or software I think one of the main differences is the size of their user communities. I doubt that any official sales figures are available, but I get the impression that the AZ-GTi has a substantially larger user base, in part because of its ability also to do equatorial, and hence better support imaging.

As a consequence, (i) the availability of crowd-sourced support is better (e.g. the SGL thread referenced above), and (ii) the support from third parties is likely to be better - for example, ADM do a saddle replacement for the AZ-GTi, but not for the Star Discovery (the last time I asked). See, for example, https://www.cloudynights.com/topic/661513-skywatcher-az-gti-useful-links-and-accessories .

 

 

Edited May 15, 2023 by Zermelo
typo

[Grump Martian]

Hi Zermelo. Thankyou for taking the time to produce such an informative response. I shall read it and the links properly this evening