Zwo harmonic mount pretty much confirmed

[vlaiv]

26 minutes ago, wimvb said:

That answers the question I had. If ZWO would drop support of other mounts, they could as well discontinue the ASIAir.

What also surprises me, is that this is the second harmonic drive mount I've come across within this last week.

https://www.aliexpress.com/item/1005003408574030.html

Silly prices is what surprises me the most

[newbie alert]

Another product about to be released without proper testing...so the consumer is the field testing guinea pig... and a updated model once the flaws have been highlighted... 

[wimvb]

1 hour ago, vlaiv said:

Silly prices is what surprises me the most

 

1 hour ago, newbie alert said:

Another product about to be released without proper testing...so the consumer is the field testing guinea pig... and a updated model once the flaws have been highlighted... 

Give it a few years, both will stabilise 😁

[Space Hopper]

2 hours ago, newbie alert said:

Another product about to be released without proper testing...so the consumer is the field testing guinea pig... and a updated model once the flaws have been highlighted... 

I think we should cut them a bit of slack.

The OPs photo at the start of the thread shows the mount in use and i'm sure its been tested thoroughly since prototype and pre production.

If problems are forthcoming been now and release (April 2022?) it will be delayed.

I'm glad to see more of these HD mounts coming out. It means prices will fall and thats a good thing for us consumers.

[gilesco]

22 minutes ago, Space Hopper said:

I think we should cut them a bit of slack.

 

I agree, testing niche products is not the same as testing washing machines and televisions which are orders of magnitude greater in production volume.

Let's wait and see, some people will take the plunge, there will be positive and negative reports and we will all make a more informed judgement down the line.

[ONIKKINEN]

5 hours ago, wimvb said:

That answers the question I had. If ZWO would drop support of other mounts, they could as well discontinue the ASIAir.

What also surprises me, is that this is the second harmonic drive mount I've come across within this last week.

https://www.aliexpress.com/item/1005003408574030.html

Thats a pretty significant price difference... Although more in line with the RST-135.

I wonder if we are heading to a new era in mount designs? Maybe the old worm drive style of mounts is an ancient relic in 10 years now that we are seeing many new harmonic drive designs, assuming one will end up working and be manufacture-able for a decent price?

[newbie alert]

1 hour ago, Space Hopper said:

I think we should cut them a bit of slack.

The OPs photo at the start of the thread shows the mount in use and i'm sure its been tested thoroughly since prototype and pre production.

If problems are forthcoming been now and release (April 2022?) it will be delayed.

I'm glad to see more of these HD mounts coming out. It means prices will fall and thats a good thing for us consumers.

Cut them abit of slack??  If the release date is April,  they still have the finalize the prototypes and then put into manufacter and ship.... that's not done in 5 mins

[david_taurus83]

1 hour ago, Space Hopper said:

I think we should cut them a bit of slack.

The OPs photo at the start of the thread shows the mount in use and i'm sure its been tested thoroughly since prototype and pre production.

If problems are forthcoming been now and release (April 2022?) it will be delayed.

I'm glad to see more of these HD mounts coming out. It means prices will fall and thats a good thing for us consumers.

Given their response to the 'Oilgate' scandal, basically suggesting customers need to clean their own £2k+ cameras at their own cost, I wouldn't cut them any slack. How do you think they'll handle disgruntled customers who find these new mounts don't perform? And we all know how how demanding we can be with our kit.

[raadoo]

6 hours ago, wimvb said:

That answers the question I had. If ZWO would drop support of other mounts, they could as well discontinue the ASIAir.

What also surprises me, is that this is the second harmonic drive mount I've come across within this last week.

https://www.aliexpress.com/item/1005003408574030.html

I knew Sharpstar were coming out with their own [first] harmonic drive mount, but I wasn't expecting it to be more expensive than Rainbow Astro's! At least Rainbow Robotics have 10 years experience with these kind of drives. Neither ZWO, nor Sharpstar can make such claims.

Probably the only positive that everyone can agree on is that we have more choice in regards to mounts now.

[vlaiv]

Out of interest, what are the stats on RST-135 - P2P periodic error and guide performance?

(given that it approaches in price to a serious mount).

[david_taurus83]

6 minutes ago, vlaiv said:

Out of interest, what are the stats on RST-135 - P2P periodic error and guide performance?

(given that it approaches in price to a serious mount).

About +-30". From their website:

 

[raadoo]

5 minutes ago, vlaiv said:

Out of interest, what are the stats on RST-135 - P2P periodic error and guide performance?

(given that it approaches in price to a serious mount).

Around 30" - but just like the Hobym (and one can only assume both the Sharpstar and ZWO) - it varies depending on load and where it's pointing in the sky. 

In terms of guide performance I've only had about 30min to play with (it's been cloudy over here for the past 5 weeks straight) but it's been around 0.9" RMS on a night of poor seeing (5" - 6" FWHM) and intermittent clouds. As others have stated, guide exposures must be kept under 1s - fortunately, I can do that with my ASI120MM Mini and OAG through an FRA400 with reducer, without trouble.

Both here and on CN there are RST-135 users who have been able to beat the periodic error even at 2000mm by employing a good guiding strategy (and hopefully future AM5 users will benefit from this as well):

• < 1s guide exposures
• a guide camera with big pixels and / or binning
• infrared (or even a simple red) filter

[vlaiv]

Let's do a little math, so we have 60" P2P (a bit more than ZWO with 40" P2P) in 430s.

That is 0-60 and then 60-0 in one cycle, so 60" is covered in roughly 215s. If we assume uniform motion - that is 0.25"/s give or take, but in reality - it will be more than that (on at least some parts of curve).

No wonder these mounts can't be guided below 0.5"-0.8". If we take too short exposure - seeing gets in the way and if we use 2-3s guide exposures - mount will move 0.75" from where it should be!

For mount to guide well it needs to have smooth varying slow PE curve. Above is simply too fast / too large P2P.

[vlaiv]

2 minutes ago, raadoo said:

Around 30" - but just like the Hobym (and one can only assume both the Sharpstar and ZWO) - it varies depending on load and where it's pointing in the sky. 

In terms of guide performance I've only had about 30min to play with (it's been cloudy over here for the past 5 weeks straight) but it's been around 0.9" RMS on a night of poor seeing (5" - 6" FWHM) and intermittent clouds. As others have stated, guide exposures must be kept under 1s - fortunately, I can do that with my ASI120MM Mini and OAG through an FRA400 with reducer, without trouble.

Both here and on CN there are RST-135 users who have been able to beat the periodic error even at 2000mm by employing a good guiding strategy (and hopefully future AM5 users will benefit from this as well):

• < 1s guide exposures
• a guide camera with big pixels and / or binning
• infrared (or even a simple red) filter

That makes perfect sense, guide exposures need to be <1s and yes, infrared is the way to go in order to beet the seeing, but even in that case, such mounts are really in 0.5-0.8" RMS territory and that is fine - but not £4000 fine (at least in my book)

[raadoo]

Just now, vlaiv said:

That makes perfect sense, guide exposures need to be <1s and yes, infrared is the way to go in order to beet the seeing, but even in that case, such mounts are really in 0.5-0.8" RMS territory and that is fine - but not £4000 fine (at least in my book)

The way I see it, we are fortunate to have such vast choice in terms of mounts to suit our individual needs:

• For those who value portability and (lack of) weight, the RST-135 is unbeatable and its price tag is fair (I'm one of them).
• For those who value capacity and precision at long focal lengths (and are fortunate to have skies with excellent seeing) their 4k could be much better spent on a CEM120EC (or a G11T, or an EQ8R Pro, etc.).

If I may be permitted an analogy: Mercedes make a G Class (off road) and an AMG GT Roadster for about the same price (130k) but they serve vastly different needs for different audiences and I venture to say it'd be unfair to compare them to each other based solely on price.

[vlaiv]

2 minutes ago, raadoo said:

The way I see it, we are fortunate to have such vast choice in terms of mounts to suit our individual needs:

• For those who value portability and (lack of) weight, the RST-135 is unbeatable and its price tag is fair (I'm one of them).
• For those who value capacity and precision at long focal lengths (and are fortunate to have skies with excellent seeing) their 4k could be much better spent on a CEM120EC (or a G11T, or an EQ8R Pro, etc.).

If I may be permitted an analogy: Mercedes make a G Class (off road) and an AMG GT Roadster for about the same price (130k) but they serve vastly different needs for different audiences and I venture to say it'd be unfair to compare them to each other based solely on price.

All fair points.

How about comparing it to something like iOptron CEM40 with RA encoders then? No need to guide, so it saves some weight and although mount head is not quite 3.3Kg, more like 7.2Kg is that weight difference really significant in portable setup (given all other components and their weight)?

I'm approaching this from strictly performance / price ratio thing rather than anything else.

[raadoo]

10 minutes ago, vlaiv said:

All fair points.

How about comparing it to something like iOptron CEM40 with RA encoders then? No need to guide, so it saves some weight and although mount head is not quite 3.3Kg, more like 7.2Kg is that weight difference really significant in portable setup (given all other components and their weight)?

I'm approaching this from strictly performance / price ratio thing rather than anything else.

For some (I imagine most?) people, yes, you're right, losing the CEM40's extra 4kg in mount + 4.5kg counterweight aren't going to be worth another €1000. For those of us with medical conditions that impose weight limits, every gram is worth it. 

You were one of the nice people who helped me make a decision in moving on from my AZ-GTi and the CEM40 was on my shortlist because it's one of the lightest in its class, counterweight included. But for me there's no denying that those 2kg less (what I saved by moving to the RST-135) make this hobby that much more enjoyable and allows me to take the rig out any time, all the time (bloody weather permitting, of course).

To be clear: I fully agree with you. A CEM40 (or even a 26) is plenty mount for most. 

Edited December 26, 2021 by raadoo

[Gfamily]

On 23/12/2021 at 12:52, nephilim said:

It looks as if the tripod leg on the left is bending under the weight of the scope, hopefully just a trick of the light.....or is it 😂😂

Massive amount of fisheye distortion in that image. Check out the shape of the doorway on the right. 🙂

[nephilim]

8 minutes ago, Gfamily said:

Massive amount of fisheye distortion in that image. Check out the shape of the doorway on the right. 🙂

There is, I hadn't noticed that 😂

[alexbb]

Partly off topic:

https://www.facebook.com/pegasusastro/photos/a.1502217729999525/3032808633607086/

[Ouroboros]

At this rate these mounts will be able to form a band and sing in “harmony”. 

[wimvb]

ZWO, Sharpstar, Pegasus Astro...

Which chinese company just developed a harmonic drive mount (and allows it to be rebranded)? It just seems too much of a coincidence that three companies independently come up with such similar designs using basically the same technology.

Btw, both the Sharpstar and Pegasus seem to have connectors on the "bottom" of the RA housing, which is bad for us living at 60 degrees North.

[CCD-Freak]

another mount going on the heap...

[raadoo]

AM5 just went up on TS’ website. Seems like that initial $2000 price tag is maybe just for the US as TS list it at €2845 for the full price, with a €210 discount for preorders.

[The Admiral]

56 minutes ago, raadoo said:

AM5 just went up on TS’ website. Seems like that initial $2000 price tag is maybe just for the US as TS list it at €2845 for the full price, with a €210 discount for preorders.

It shows this on the website from the UK

Ian