Sky-Watcher wave 150i

[globular]

12 minutes ago, vlaiv said:

Not sure which one is that (not that much into strain wave market).

 

500i was a typo - I meant 150i (the subject of the thread).  

[vlaiv]

2 minutes ago, Elp said:

In Cuivs review is was on par with his Warpastron WD20 which is direct servo drive, so are we missing something in terms of the differences in mechanical setup between these mounts?

That "direct servo drive" - is very misleading.

In that context - every motor is "direct drive" - as it "directly drives the output shaft".

When we talk about true direct drive mounts - we are talking about mounts that don't have mechanical reduction (and hence don't use strain wave reducer or any other kind of reducer) - and where axis is directly coupled with output shaft of motor.

Servo setup must be used as it is only setup that has the potential to have enough precision for this application - but it requires very high accuracy absolute rotary encoders (probably at least 22 bit ones - but more like 26 bit).

Other than that - regular servo motor with 12bit encoder is on par with stepper motors in terms of positioning precision and accuracy. 1.8 degree stepper with 32 micro steps has 200 x 32 = 6400 positions per revolution. 12bit encoder allows for 4096 positions per revolution. Accuracy of servo depends on accuracy of absolute encoder and also depends on driver (how well it keeps currents needed to retain position).

From what I've gathered - these strain wave drives are hugely overpriced.

I've looked into reducers myself for DIY builds and found that most of them come from a single factory in China (sounds familiar, right? ).

Most of reducers used in mounts are in price range of $150-$200 per unit - so that is total of $400 max for reducers. Stepper motors and electronics is order of $50-$60 and not sure how much does machining of housing cost - but my estimate of total costs is probably in ballpark of $600-800. Yet those units go for x3-x4 that much money.

For those that are interested - here is Polish company that makes them:

https://promakers.pl/eqhm-17/

and if anyone wishes to DIY - Fishy Tony is the guy to talk to

https://www.tonifishi.com/sy

(this is company that is making all those strain wave drives - just select model to suit your motor size - 14 / 17 / 20 and other characteristics and of you go ...)

 

[Elp]

They're high priced for sure, but you can't put a price on straining your back/body moving around heavy setups... In an obsy/semi permanent setup you don't have this issue.

[vlaiv]

4 minutes ago, globular said:

500i was a typo - I meant 150i (the subject of the thread).  

I think that both mounts use exactly the same mechanical setup:

Nema 17 stepper with 100:1 reduction for RA (+x3 reduction with belt) and Nema 14 stepper with 100:1 reduction for DEC (again + x3 reduction with belt).

If you look at Fishy Tony list of products - you will likely find reducers that they are using - probably F14 and F17 models:

https://www.tonifishi.com/productinfo/1169661.html

And if you go to aliexpress - you will find those reducers under different brand names (but same picture and same specs):

https://www.aliexpress.com/item/1005004654576817.html

(that is S14/S17 series from Fishy Tony - I just love writing that - reminds me of New York gangster or something ).

[rjsc2001]

2 hours ago, Elp said:

To the item or his content?

To the review video 

[Elp]

3 hours ago, rjsc2001 said:

To the review video 

See this thread:

 

 

[Lucas M]

Now that, is a very exciting delivery....

[TiffsAndAstro]

1 hour ago, Lucas M said:

Now that, is a very exciting delivery....

Let us know how you get on with it. Think it's going to be very impressive.

[Bubbles82]

5 hours ago, Lucas M said:

Now that, is a very exciting delivery....

Can’t wait to hear what you think I’m still between this and the Am5

[Lucas M]

OK, very quick thoughts after night 1...

Lots of high cloud around so the imaging session was never going to be great but it was clear enough to set up, polar align, and set her going and see how she got on

Here is a shot of the mount next to my existing Star Adventurer GTI, size wise it isn't much different, it is a little bulkier and a smidge heavier but obviously it can take 5x the load the gti can but I thought it was an interesting comparison!

Here she is out on the balcony this morning after the night of imaging, as you can see (if you zoom in a bit), thanks to the in built cable management there are no cables that cross any movement axis, simply 1 usb and 1 power from the asiair to the mount saddle and then they both "pop out" on the stationary back panel of the mount.

This "pass through" is a great solution and better (in my opinion) than the AM5n solution of having the control port for the mount on the saddle... I could simply have a powered USB hub sat on the scope plugged into the saddle and then plug the back panel output directly into a laptop running NINA and then just just a separate cable from the laptop to the actual mount control point and still be completely free from snag risk... that is not possible with the AM5n as far as I am aware.

 

The mount seems really nicely built (seems built like a tank actually) everything is tight but smooth, it sounds like something out of star trek compared to the slight grinding sound of my gti.

super easy to get up and running, took my no longer to ser up and get imaging with than my previous set up but I was swapping one skywatcher mount for another, maybe if you were coming from a different brand it may take more getting used to.

I DID balance the DEC axis... I couldn't bring myself to not do it 🤣 was super quick, remove 2 thumb screws to unlock the axis, do your balancing and pop them back in, easy.  Only niggle... you probably only have about 30 degrees of movement once the axis is unlocked so not a lot, just enough to check balance but MUCH less than you will be used to.

Here is the guide graph from the asiair, I didn't do anything to dial in the guiding and it was guiding through high cloud, this figure was pretty typical.  I just let the asiair calibrate the guiding all the settings were the same as for my previous mount... admittedly my little 5kg rig is not a big test for this mount but it is a start...

Skies are due to be crystal clear tonight so I will do some work to dial in the guiding and then upload the full PHD2 guide logs tomorrow so people can review them if they so desire.

 

So conclusions after first light... love it, well built, easy to use, seems to work well so far 👍

[TiffsAndAstro]

Nice post Ty. I gave up about midnight, my guiding was all over place on my sw gti and I'm blaming high cloud...

[Bubbles82]

9 hours ago, Lucas M said:

OK, very quick thoughts after night 1...

Lots of high cloud around so the imaging session was never going to be great but it was clear enough to set up, polar align, and set her going and see how she got on

Here is a shot of the mount next to my existing Star Adventurer GTI, size wise it isn't much different, it is a little bulkier and a smidge heavier but obviously it can take 5x the load the gti can but I thought it was an interesting comparison!

Here she is out on the balcony this morning after the night of imaging, as you can see (if you zoom in a bit), thanks to the in built cable management there are no cables that cross any movement axis, simply 1 usb and 1 power from the asiair to the mount saddle and then they both "pop out" on the stationary back panel of the mount.

This "pass through" is a great solution and better (in my opinion) than the AM5n solution of having the control port for the mount on the saddle... I could simply have a powered USB hub sat on the scope plugged into the saddle and then plug the back panel output directly into a laptop running NINA and then just just a separate cable from the laptop to the actual mount control point and still be completely free from snag risk... that is not possible with the AM5n as far as I am aware.

 

The mount seems really nicely built (seems built like a tank actually) everything is tight but smooth, it sounds like something out of star trek compared to the slight grinding sound of my gti.

super easy to get up and running, took my no longer to ser up and get imaging with than my previous set up but I was swapping one skywatcher mount for another, maybe if you were coming from a different brand it may take more getting used to.

I DID balance the DEC axis... I couldn't bring myself to not do it 🤣 was super quick, remove 2 thumb screws to unlock the axis, do your balancing and pop them back in, easy.  Only niggle... you probably only have about 30 degrees of movement once the axis is unlocked so not a lot, just enough to check balance but MUCH less than you will be used to.

Here is the guide graph from the asiair, I didn't do anything to dial in the guiding and it was guiding through high cloud, this figure was pretty typical.  I just let the asiair calibrate the guiding all the settings were the same as for my previous mount... admittedly my little 5kg rig is not a big test for this mount but it is a start...

Skies are due to be crystal clear tonight so I will do some work to dial in the guiding and then upload the full PHD2 guide logs tomorrow so people can review them if they so desire.

 

So conclusions after first light... love it, well built, easy to use, seems to work well so far 👍

Thanks for taking the time to do this first light report, I really appreciate the details as It was me that originally asked some to hurry up and buy one 😂. This has swayed me right back towards the wave 150. I genuinely can’t wait to hear your thoughts over the next few trips out with it and it’s sitting in my basket online. One big question I have and I may not be alone is how does this perform when treated like other harmonic drive mounts and is not balanced in anyway. I only ask for sort of 2 reasons,

1: One of the big pluses for me having an harmonic mount is not having to balance the mount like my eq mount. So I would try to never touch the clutches.

2: I always feel that balancing the rig and all the expensive bits together is always when damage to our expensive kit comes highest and I’ve had few close calls myself.

I would love to hear any feedback if anyone gets the chance to try this at some point in the near future with this mount, we can call it “that will do,the dovetails kind of in the middle “ setting 😂

[Elp]

I'm interested to hear if the RA clutch knob will ever give you an issue as without CWs it could cause a disaster scenario if loose, as far as I know, no other HD mount has this feature.

[Lucas M]

14 minutes ago, Elp said:

I'm interested to hear if the RA clutch knob will ever give you an issue as without CWs it could cause a disaster scenario if loose, as far as I know, no other HD mount has this feature.

On this point 1 thing I will say from playing with both the DEC and RA axis clutch knobs is that they have to be completely removed to unlock the axis, being loose is not enough to allow rotation of the axis.

Secondly, they are both stiff as hell and quite long, so it takes some definite effort to remove them, the chances of absentmindedly doing it by accident are very very slim and the chances of them them working themselves loose also seems very low from how they feel right now, but time will tell.

Interestingly there are 2 bolts which need removing to unlock the DEC axis, but only 1 to unlock the RA axis, but the RA one is longer.

[Lucas M]

Sorry for the short delay, here are the first two nights guide logs for analysis by anyone that wants to do a deep dive.

Caveats...

• My rig sits on a balcony that bounces when you think about walking around in the house, so stability is an issue
• Although these nights were pretty calm, I live on the north west coast... wind is a constant issue
• Night one (16/09) had a 100% cover of high cloud all night)
• I am no expert in getting the best out of guiding.

That being said, for me this is a solid purchase, it was an upgrade from my Star Adventurer GTI which is obviously blows out the water

 

You can see below the RA error is sitting from about -16" to +11 so well within the ±20" the original AM5 shipped with but outside of the ±10" the AM5n states now, I must stress though, there is a BIG difference from the error you will get testing on a test bench in a factory to the actual error seen in use, so for me this is looking pretty darn good.

 

Here is the analysis of the periodic error, seems to sit at about 286 seconds, so if you are doing 5 minute subs you will get the spike from the periodic error in every frame, although noticeable compared to the rest of the guide graph it is still pretty small, maybe if you are using longer focal lengths this is something you would have to think about but it is not different in that regard to any other harmonic drive mount I guess

 

Ok, that's about all I can glean from this data, as mentioned previously I am no expert on this stuff, so, to sum up, it's robust, it's quiet, it's quick, it's accurate, it tracks/guides well, the cable management is excellent and it looks great.

If you are already a sky-watcher user and you are looking to move to a harmonic drive mount I do not see why you wouldn't choose this one, if you are still torn between the ZWO offering (or any of the many other harmonic drive mounts out there) and this, the cable management is what swayed it for me and it still would, but if you aren't that bothered by cables then really just pick a colour, red or black  

PHD2_GuideLog_2024-09-16_231613.txt PHD2_GuideLog_2024-09-17_204854.txt

Edited September 20 by Lucas M

[Bubbles82]

17 hours ago, Lucas M said:

Sorry for the short delay, here are the first two nights guide logs for analysis by anyone that wants to do a deep dive.

Caveats...

• My rig sits on a balcony that bounces when you think about walking around in the house, so stability is an issue
• Although these nights were pretty calm, I live on the north west coast... wind is a constant issue
• Night one (16/09) had a 100% cover of high cloud all night)
• I am no expert in getting the best out of guiding.

That being said, for me this is a solid purchase, it was an upgrade from my Star Adventurer GTI which is obviously blows out the water

 

You can see below the RA error is sitting from about -16" to +11 so well within the ±20" the original AM5 shipped with but outside of the ±10" the AM5n states now, I must stress though, there is a BIG difference from the error you will get testing on a test bench in a factory to the actual error seen in use, so for me this is looking pretty darn good.

 

Here is the analysis of the periodic error, seems to sit at about 286 seconds, so if you are doing 5 minute subs you will get the spike from the periodic error in every frame, although noticeable compared to the rest of the guide graph it is still pretty small, maybe if you are using longer focal lengths this is something you would have to think about but it is not different in that regard to any other harmonic drive mount I guess

 

Ok, that's about all I can glean from this data, as mentioned previously I am no expert on this stuff, so, to sum up, it's robust, it's quiet, it's quick, it's accurate, it tracks/guides well, the cable management is excellent and it looks great.

If you are already a sky-watcher user and you are looking to move to a harmonic drive mount I do not see why you wouldn't choose this one, if you are still torn between the ZWO offering (or any of the many other harmonic drive mounts out there) and this, the cable management is what swayed it for me and it still would, but if you aren't that bothered by cables then really just pick a colour, red or black  

PHD2_GuideLog_2024-09-16_231613.txt 786.53 kB · 0 downloads PHD2_GuideLog_2024-09-17_204854.txt 2.13 MB · 1 download

Thanks for taking the time again to upload the data and give your thoughts, having now heard a real life user giving a positive review after some in action testing I’m convinced.

[Ardsley Astro]

23 hours ago, Lucas M said:

Sorry for the short delay, here are the first two nights guide logs for analysis by anyone that wants to do a deep dive.

Caveats...

• My rig sits on a balcony that bounces when you think about walking around in the house, so stability is an issue
• Although these nights were pretty calm, I live on the north west coast... wind is a constant issue
• Night one (16/09) had a 100% cover of high cloud all night)
• I am no expert in getting the best out of guiding.

That being said, for me this is a solid purchase, it was an upgrade from my Star Adventurer GTI which is obviously blows out the water

 

You can see below the RA error is sitting from about -16" to +11 so well within the ±20" the original AM5 shipped with but outside of the ±10" the AM5n states now, I must stress though, there is a BIG difference from the error you will get testing on a test bench in a factory to the actual error seen in use, so for me this is looking pretty darn good.

 

Here is the analysis of the periodic error, seems to sit at about 286 seconds, so if you are doing 5 minute subs you will get the spike from the periodic error in every frame, although noticeable compared to the rest of the guide graph it is still pretty small, maybe if you are using longer focal lengths this is something you would have to think about but it is not different in that regard to any other harmonic drive mount I guess

 

Ok, that's about all I can glean from this data, as mentioned previously I am no expert on this stuff, so, to sum up, it's robust, it's quiet, it's quick, it's accurate, it tracks/guides well, the cable management is excellent and it looks great.

If you are already a sky-watcher user and you are looking to move to a harmonic drive mount I do not see why you wouldn't choose this one, if you are still torn between the ZWO offering (or any of the many other harmonic drive mounts out there) and this, the cable management is what swayed it for me and it still would, but if you aren't that bothered by cables then really just pick a colour, red or black  

PHD2_GuideLog_2024-09-16_231613.txt 786.53 kB · 1 download PHD2_GuideLog_2024-09-17_204854.txt 2.13 MB · 2 downloads

I'd be interested if you got even better results with a 50mm 190mm focal length guide scope. If Your using the Synscan app you can use it to set PPEC in the mount also.