ZWO AM5 - Experience and lessons learnt

[Elp]

I was also wondering how you'd achieve declination balance safely without a locking mechanism, is it done by switching the mount on and off, adjust and repeat? Or is guiding unaffected by an unbalanced dec payload?

[david_taurus83]

2 hours ago, George Sinanis said:

 My heaviest rig till now is the Stellamira ED90 triplet, which weighs 7kg, if I remember well, with everything on it; my concern here though is not the weight but, the length. It is over 1.7m in length. Next time I get this ota in use, I will perform some tests and see how the mount behaves.

1.7 metres in length? Almost 6 foot? Surely not!

[AstroGS]

2 hours ago, david_taurus83 said:

1.7 metres in length? Almost 6 foot? Surely not!

It will be my dream to have a 1.7m ota…. You are right. I meant over 0.7m. 

[StevieDvd]

There's no balancing option on these mounts. I guess the idea is that the motors are not bothered by the weight as much as other types of mount.  A little noe in the AM5 manual mentions checking for stability so it should only be used by people with common sense 😄

A heavy refractor should be easier for it to handle (compared to a SCT f the same weight) as the weight is closer to the centre of balance.

The danger of the 0.7m refractor (and camera train etc) touching/crashing is dependent on whether the user checks for free movement or not. 

I'm happy with my current setup needing no counterweight, I can hold the mount fully loaded with scope/camera/guidescope/asiair in one hand - though of course use the other hand as well when carrying it to the pier or tripod.

But I do have an extension bar that fits and some small weights if I put a larger scope on, as I have this mental image of Scotty from Star Trek telling me you can't change the law of physics.

[Elp]

Just enquired as my C6 at 1000mm FL (f6.3 mode) is back heavy and I don't have any more dovetail to clamp to, so may be an issue with that configuration unless I devise some sort of CW solution to the front end.

[TerryD]

Thanks for the write up.  I just ordered an AM5 and your shared experience will hopefully help me out while getting started with this mount.

[AstroGS]

6 hours ago, TerryD said:

Thanks for the write up.  I just ordered an AM5 and your shared experience will hopefully help me out while getting started with this mount.

It is a great mount and probably one of the most versatile mounts in the market. Tracks well and holds a fair amount of weight. 

[AstroGS]

The weather decided after almost 7 weeks straight with clouds, to do us a favour and offer us a few evenings with clear skies.

It does seem that the mount is delivering much better results now - it probably needed some period of breaking in - but, managed to get some very solid guiding over 2 nights this week. I used the 90mm triplet with the 2600MC (approx. 7 kg payload) to do some galaxy imaging. The only difference compared to the previous setup is that I replaced the guidescope with a ZWO OAG + the ASI290mm mini and it seems that is perfect.

 

Both days the mount tracked between 0.4 and 0.6, with some lows as 0.33 (!!) for an hour or so. Here are some screenshots of those sessions.

 

 

[AstroGS]

Finally got a clear night last evening and went for the M106 that was pretty much at the zenith during the whole session. 
 

300 sec subs, seeing was good but, there was some wind that had some effect on the guiding and I had to increase Dec/RA aggression. 
 

Overall guiding was around 0.5” - 0.6”, which I consider very good. Overall rig weight around 7kg. 

[AstroGS]

Another great session last night with the Redcat51, fully loaded on the AM5 - actually it might have been the best so far on guiding, with permanently guiding between 0.3” and 0.4”. The mount is definitely performing better now but, I’m not sure if something changed during latest updates (mount/Asiair) or it just needed some time to settle down.

 

Sharing with you some screenshots of the settings for the evening, in case it helps.