Mount Upgrade Options

[Saturn488]

I am looking to upgrade from my HEQ5 Pro later in the year and having a look at the various options.

Looking into both the Skywatcher EQ6-R but also the harmonic drive mounts, specifically the iOptron HEM27. Both have 20kg payload capacity (HEM27 would need a counterweight) which is more than enough. I primarily use refractors and my heaviest setup is 9kg so taking future additions into account I don't think I will surpass 12kg. If I buy an SCT like an Edge 8 or a RASA 8, even then I might be pushing it up to 15kg after attaching all the gear so I have plenty of payload capacity.

What I really like about the HEM27 is how portable it is which is perfect for travelling and the fact you don't need a counterweight for under 12kg.

My budget would be no more than $3,500 so for that money there are really only two options that can take a payload capacity of 20kg.
- iOptron HEM27 + iPolar $3,299
- Skywatcher EQ6-R $2,799

I know harmonic drive mounts are still the new kid on the block for telescope mounts and the good old classic mount has been around for ages which is one of the reasons why I am diving into unknown waters with the harmonic drive mount.

Thoughts? Advice? Feedback on anyone who owns these mounts?

[Startrek]

My experience with the EQ6-R pro mount …….
I’ve had 2 x EQ6-R mounts since 2019, one in Sydney and one on the South Coast NSW
Can’t fault them , they track and guide beautifully
Sydney payload 6” Newt fl 900mm about 9kg
South coast payload 8” Newt fl 1000mm 14kg
Guiding on stable nights around 0.50 to 0.60 total
Dec backlash around 900ms although I could spend more time and get it down lower but that’s more than acceptable
I’ve mini tuned both ( adjusted Ra and Dec worms and drive belts ) very easy to do takes 20 to 30 mins
I run EQMOD and Stellarium for Goto and tracking
For the money they are excellent value and just work ( like the older gear driven EQ6 but smoother and whisper quiet )
I progressed from an EQ5 in 2016 to HEQ5 to EQ6-R’s and now an EQ8-R pro

Hope the above is helpful

Cheers
Martin

PS: Personally I wouldn’t load them more than 15kg unless your in an Obs or on a pier

[AdamJL]

If you're going to choose a strain-wave mount, don't do the hybrid stuff. Go full strain-wave. So that's either the Pegasus Nyx, Rainbow Astros or ZWO AM5.

I have both an EQ6-R and AM5. The main question I have is this: do you have a permanent setup or will you be setting up each night? If it's the latter, in my view, the strain-wave mounts are a no-brainer. Setup time is annoying, and strain-wave mounts allow you to plonk your gear on and not bother about balancing. No counterweights for your weight class, and the mounts weigh next to nothing. Please don't discount that part. As we all age, these heavier mounts become more and more cumbersome.

That said, I drive my EQ6-R with 17.5kg of gear on top, so they are indeed very good. I know someone else who puts 21.5kg on their EQ6-R as well.

[Saturn488]

Interesting feedback guys.

I have a permanent pier.

[The_bluester]

One thing that seems to be missing from the iOptron (And is certainly missing from the EQ6-R, it just wasn't a 'thing" when they were designed) is home position sensors. Depending on your level of automation they can be the difference between a 10 minute interruption to imaging, or the loss of whatever the rest of the night is.

My CEM70G has them and in the case of things going seriously south (Which does not tend to happen with my gear, but a friend also with a CEM70G can sometimes see this) I can have my software (Voyager) do anything up to a reboot of the imaging PC and go again from there as my nightly routine starts with remotely homing the mount. If you can't do that you have to trust that the mount has actually stopped where you expect (Park or home)

With my Orion Atlas (AZEQ6 clone) I can't do that homing procedure so a reboot will mean EQMOD fires up assuming the normal pointed at the pole, counterweights down position, if it is not there I risk either rejected syncs from plate solves or equipment crashes.

Equipment crashes is one other thing I wonder about with the strain wave mounts, if they can produce enough torque to lift a 20KG payload without a counterweight, are they a higher risk of equipment damage in the case of a crash? Thinking of a pier crash around the meridian with 20KG+ of force on the side of the camera.

[Startrek]

One annoying side of using a mount with homing sensors like my EQ8-R and one that doesn’t like my EQ6-R is that I have to reset encoders in EQMOD each time
When using the EQ6-R I have to run up Synscan HC and put mount into standby then park to home position and save. Then start EQMOD select Park to Home Position then rest encoders. The icon then moves back to the Home position or SCP
Similar for the EQ8-R but run up Synscan HC , select Auto Homing, once done leave the mount in standby. Start EQMOD select Park to Home Position then reset encoders
I do run EQMOD at 2 different sites same laptop with separate Site information profiles
Chris Shilito from EQMOD forum gave me the above procedures to resolve my issues. The telescope icon would be sitting out in left field somewhere so not a good place to start your Goto . Now it resets back to the SCP on both mounts.
A nice workaround only takes 10 mins. Chris has given tireless support for EQMOD for many many years
Cheers
Martin

[The_bluester]

That is one thing that is a big advantage of the iOptron (CEM70 at least) “Seek home” is available via ascom and is a sync event. You can power it off in any position, or release the gear and move it manually but if you seek home it does so and syncs to that position so it is immediately ready for a goto. And provided the base is decently level it is close enough to jump straight in to plate solving to center a target without needing a blind solve to start off.

Is it not possible via ASCOM to send the EQ8-R home automatically and have it sync on that position? A bit of an odd design choice if that is the case.

[Startrek]

Unfortunately not with Synta mounts although I suspect someone with an electronics background has probably done a workaround

Also I don’t plate solve, I use sync point modelling with EQMOD and Stellarium
My rig is not fully automated so I manually operate the park function at the end of an imaging run ( I don’t need to get in the morning to go to work , retired )
The EQ8-R was marketed in 2019 as a Observatory Class mount , obviously not a bonafide Obs mount , then they brought the EQ8-RH out which has Ra axis Renishaw encoders and few other add ons for an additional $4K

[The_bluester]

The beauty of the iOptron setup (And doubtless others) in my situation is that it can recover from everything up to a power failure. The NUC will boot when power comes back on, and Windows is set up to start Voyager using the standard script I have for all nights, the first thing it will do (If it is after astronomical night has started) is connect the setup, cool the camera and home the mount before continuing on from wherever it was up to.

I am surprised that they have not set the EQ8-R up to be able to be easily homed and synced automatically, it makes problem recovery so much easier. Even if I was not leaning on automation, my Atlas versus my CEM70 is the difference between a trip out to the mount at 2AM to manually put the Atlas back in the park position to avoid the risk of a crash, and homing the CEM70 via a remote desktop session.

[Leo.G]

I've been researching these drives, can't afford one, not likely in this life time but I have noted they all mention electronic braking in case of a power outage or any other electrical failure which is to prevent the disaster you've mentioned.
This may have been answered already, it's 1:40AM and I'm full of sleeping tablets and should be staring at the inside of my eyelids. My reading skills aren't currently great

[The_bluester]

Not quite the disaster I was meaning, the brake should prevent the mount from running away and smashing the payload into the pier/tripod in case of a power failure, I was wondering about the amount of force the mount could apply in an equipment crash around the zenith. For instance, the mount has tracked through the zenith and the camera has hit the pier/tripod. In that case without a counterweight it would be whatever force the mount is applying, plus some amount for the payload itself as it is past the vertical (And not counterbalanced)

I routinely run both of my mounts 15 to 20 minutes west of the meridian before flipping, to avoid losing imaging time in what should be the best part of the sky.

[Saturn488]

Let’s throw in the AM5.

Thoughts? Worth it? Too early for this newer tech in the mounts?

[joshman]

I have the AM5 and it has been the best investment in gear I have made. As AdamJL pointed out above, if you're going to go down the strain wave route, go all the way. Having a mount that doesn't require counterweights, nor balancing, means i can leave it setup, and just need to plonk it out in the yard and align it to get imaging. I can be setup and ready to image in well under 10 minutes.

having a system with minimal setup time, means that i am using it more. My current imaging train is about 10kg, and i'm routinely seeing around 0.5" RMS in my guiding.

I haven't encountered or tested any of the power failure scenarios mentioned above, so i can't comment on that. But be mindful that a SW gear mount doesn't have clutches, so if your equipment makes contact with your tripod or pier, it will keep driving until something gives way, or it cuts power on motor overload.