RR RST-135 Goto Mount

[Rob]

Seriously like the look of this!. I wonder who the stockist is for Europe/UK. I feel some saving up is in order.

http://www.rainbowastro.com/new/theme/basic/content/product-135.php

 

 

Edited April 15, 2019 by Rob

[xtreemchaos]

nice mount but the price is up there too far for most mortals to reach when theres loads of other cheaper mounts to have.charl.

[Rob]

4 minutes ago, xtreemchaos said:

nice mount but the price is up there too far for most mortals to reach when theres loads of other cheaper mounts to have.charl.

I agree Charl.. but wow. Its stuff of engineering dreams!. And looks so slick. The payload with no weights to boot. Its certainly a glimpse of the future 

[Craney]

Agree, it looks very swish...

Is that a hand tightener on the polar axis ??     18kg is a lot to have levered on a hand tightened knob  !!..... especially with a 'cheap' expendable  Tak swinging around on the end of it.

Lets hope the big manufacturers take note and get the price down.

[tonyowens_uk]

I think the principles of their design are spot-on.

1. No counterweights: These are an Edwardian engineering anachronism that have no other function than to allow badly-designed worm gearing to deliver acceptably smooth operation and wear life. Sadly the GEM with counterweights has become something of a meme. Industrial robots have managed to combine good accuracy and repeatability for many years without resorting to them, as have professional scope mounts.

2. Compact and lightweight. The value of this to end-users is more substantial is commonly realised by equipment manufacturers. The success of giant-killing small tracking AltAz mounts from iOptron and Skywatcher is evidence of that. With the shift away from long exposure CCD technology to CMOS stacked subframes, and the growing awareness that high resolution (>24 bit) axis encoders and direct drive provide no compelling advantages over an autoguided open-loop mount outside a permanent observatory, I expect to see fewer cost-optimised 'toy' tracking AltAz mounts in the future and more 'authentic' mounts based on industrial automation technology, like this one.

3. Billet-machined construction. This offers no functional advantages whatsoever compared with a mount made from machined castings (and sometimes serious stiffness disadvantages), but in the minds of many buyers it connotes superior performance

4. Freedom from routine mechanical maintenance. This is increasingly important as imaging equipment proliferates, and it characterises harmonic-type reducers as are used here.

 

The pricing is going to be an issue I suspect.

The controls environment (ASCOM, smartphone interfaces, homing, cable-wrap, backlash detection and compensation, sky modelling) is generally a greater challenge than the mechanical engineering. It will be interesting to see how well evolved this is.

All credit to the developers for bringing this to market!

Tony Owens

[Guest chaz2b]

The pricing seems to emulate the likes of modern motorcycles, less is more.

just had a look at their site,and looked up the harmonic drive system, well it won’t come cheap as the drives are very expensive on their own! The 150 will take more weight,obviously, but the price is 2.5 times more. In terms of the portability, you really can’t compare, it’s the Ferrari of mounts, very light and compact, but out of my price range.

I’ve edited my first reply as I thought it was a bit flippant of me.

chaz

Edited May 14, 2019 by chaz2b

[Guest chaz2b]

On 15/04/2019 at 10:36, Craney said:

Agree, it looks very swish...

Is that a hand tightener on the polar axis ??     18kg is a lot to have levered on a hand tightened knob  !!..... especially with a 'cheap' expendable  Tak swinging around on the end of it.

Lets hope the big manufacturers take note and get the price down.

The 135 can carry 13.5 kg and it’s bigger brother the 150 can carry 15 kg, but for the extra 1.5 kg the price is 2.5x more!

The claim is no counter weights, but they do provide for a 3kg counterweight.

chaz

[The Admiral]

On 15/04/2019 at 08:31, Rob said:

Seriously like the look of this!. I wonder who the stockist is for Europe/UK.

Well this technology has tickled my interest (though not the wallet! Yet!!). It is currently listed on the @FLO site. The specs would be ideal for my situation as all my gear has to be carted down from upstairs and set up in the garden each session. There are several review threads posted on the CN site which are worth a read. There is some discussion on the tracking precision, especially for the cost, some of which is beyond me, but the thrust seems to be to use it on a photo tripod for portability. I can't see how you could expect sub arcsec precision without a more substantial tripod, given the assymetry of load, but what do I know.

At the more practical level, I would want to use something like an iOptron Tri-pier and the iPolar, rather than a Polemaster, so it comes down to the availability of adapters. Early days yet.

Ian

Edited December 8, 2019 by The Admiral

[Stephen Hawking]

I'm thinking about pulling the trigger on this one.  Any thoughts?

 

[tonyowens_uk]

On 08/12/2019 at 19:04, The Admiral said:

Well this technology has tickled my interest (though not the wallet! Yet!!). It is currently listed on the @FLO site. The specs would be ideal for my situation as all my gear has to be carted down from upstairs and set up in the garden each session. There are several review threads posted on the CN site which are worth a read. There is some discussion on the tracking precision, especially for the cost, some of which is beyond me, but the thrust seems to be to use it on a photo tripod for portability. I can't see how you could expect sub arcsec precision without a more substantial tripod, given the assymetry of load, but what do I know.

At the more practical level, I would want to use something like an iOptron Tri-pier and the iPolar, rather than a Polemaster, so it comes down to the availability of adapters. Early days yet.

Ian

If you have to tote a tripod for non-permanent use, and need this to be capable, I'd highly recommend a heavy-duty well-designed wooden tripod. Berlebach is a German firm that offers models stiff and well-damped enough to work well, yet the weight for moving it around (in the deployed state) is manageable. The engineering is painstaking. I use one of their Planet models with an EQ8 occasionally to carry up to 30Kg imaging payloads and the stability is most impressive.

Tony

[The Admiral]

On 05/01/2021 at 22:44, tonyowens_uk said:

If you have to tote a tripod for non-permanent use, and need this to be capable, I'd highly recommend a heavy-duty well-designed wooden tripod. Berlebach is a German firm that offers models stiff and well-damped enough to work well, yet the weight for moving it around (in the deployed state) is manageable. The engineering is painstaking. I use one of their Planet models with an EQ8 occasionally to carry up to 30Kg imaging payloads and the stability is most impressive.

Tony

Thanks for the advice. I had heard that the Berlebach tripods were highly rated.

As it happens, I ended up buying an iOptron mount at the beginning of lock-down 1.0 last year, and that came with a tripod. Actually, I think the weight is not much different to the Berlebachs.

Ian

[Davey-T]

On 01/01/2021 at 15:34, Stephen Hawking said:

I'm thinking about pulling the trigger on this one.  Any thoughts?

 

Hi Stephen and welcome to SGL.

Having had one of these for a while it performs well especially with my very unbalanced rig however there are a couple of cons

The azimuth adjustment bolts have a very fine metric thread which may sound like a good idea for accurate PA but they're a very loose fit in the thread and simply jump in the thread if tightened  to move a heavy unbalanced load, the casing with the AZ thread needs to be meatier with a bigger better fitting bolts.

On the balancing front if you were to need to fit any substantial weights to stop the tripod tipping over the thread for the weight bar is far too small on the upside it fits a SW Star Adventurer bar so a lot cheaper than the Rainbow alternative.

Having the on off switch and the ST4 port on the top surface makes them very prone to the ingress of heavy dew it needs a sealed on off switch with a rubber cover and the ST4 port needs a plastic  plug similar to that fitted to ZWO cameras.

The handset is pretty confusing, looks like it was designed by a computer programmer trying to reinvent the wheel rather than following the normal conventions, in fact the whole thing appears to have been designed by engineers rather than astronomers.

In spite of these gripes it works well so all in all I'm happy with it.

Dave

 

 

[The Admiral]

11 minutes ago, Davey-T said:

The azimuth adjustment bolts have a very fine metric thread which may sound like a good idea for accurate PA but they're a very loose fit in the thread and simply jump in the thread if tightened  to move a heavy unbalanced load

Hmm, that doesn't sound good. Is this with the so-called improved polar alignment adjustment?

Just out of interest (there's no way I could afford one ), have you found guiding to be problematic?

Ian

[Davey-T]

3 hours ago, The Admiral said:

Hmm, that doesn't sound good. Is this with the so-called improved polar alignment adjustment?

Just out of interest (there's no way I could afford one ), have you found guiding to be problematic?

Ian

I use a complete ZWO setup with Asiair Pro and that has a good PA routine just the Alt Az mount adjusters are a bit fragile, there is a fitting for a Polemaster.

Use the PHD2 built into the Asair Pro and guiding is good.

Dave

[UKRoman]

I’ve had one if these mounts for a few weeks now. The portability is excellent. I got one because I was fed up of carrying my heavy AZ-EQ6 Pro up and down stairs. This is so light that I move it around pretty much completely assembled. On that front I’m completely happy. 
 

Guiding is interesting though. I don’t seemed to have cracked that yet. The best figures I’ve had via my ASIAIR Pro are around 1.5” and it can vary up and down quite considerably. That said, it doesn’t seem to affect my images, which is what counts at the end of the day. I intend to try the mount with my laptop and PHD2 to see if I get better figures, just in case it’s the ASIAIR that’s simply reporting it differently. 
 

I’m using the mount on an Artcise AS90C tripod, which provides a solid base when used in conjunction with an 85mm refractor. 
 

All-in-all the RST-135 is doing what I wanted it for and so far I haven’t gone back to my AZ-EQ6. So I’m pretty happy with it. 

Edited January 10, 2021 by UKRoman

[The Admiral]

15 hours ago, Davey-T said:

I use a complete ZWO setup with Asiair Pro and that has a good PA routine just the Alt Az mount adjusters are a bit fragile, there is a fitting for a Polemaster.

Use the PHD2 built into the Asair Pro and guiding is good.

Dave

Thanks Dave, but what I meant is that the mount is now advertised as having "Latest Version with Improved Polar Alignment Adjustment" which I took to be an improved mechanical adjustment, as I know this is an area that was criticised in reviews. Is this not the case as far as you know?

Ian

[Davey-T]

2 hours ago, The Admiral said:

Thanks Dave, but what I meant is that the mount is now advertised as having "Latest Version with Improved Polar Alignment Adjustment" which I took to be an improved mechanical adjustment, as I know this is an area that was criticised in reviews. Is this not the case as far as you know?

Ian

I think this was to do with that lever that sticks out the front to lock the AZ adjustment, the original design was causing problems with it jamming I believe but it was fixed before I got mine.

As I mentioned the only problem now is the AZ adjustment bolts not being man enough to move an unbalanced load, they are aware of this but to fix it would require a major redesign so doubt it will happen anytime soon.

Dave

[bogdanbacila]

Just ordered mine five days ago. Due to the Chinese new year it should arrive at the end of the month in Italy, and then probably one more week till Romania.
Did allot of reading on the internet, and also saw some interesting youtube video with owners who already use one, stating the pros and cons of the mount.

In the end, if I would manage to guide it as my avalon m-zero, I would be really happy. There is a common opinion as the RST-135 guides really well with short exposures 0.5-1s and small and aggressive corrections. We'll see how that goes.

On the AZ adjustment, if you load gear up to 8Kg, I guess it shouldn't be a problem while aligning, and if you go over that, just simply use a counterweight.. or maybe I'm mistaking..
 

Would be really interested if some of the existing users would post some guide graphs here, together with the RA/DEC/total RMS they got.

[Highburymark]

On 10/01/2021 at 14:10, Davey-T said:

I think this was to do with that lever that sticks out the front to lock the AZ adjustment, the original design was causing problems with it jamming I believe but it was fixed before I got mine.

As I mentioned the only problem now is the AZ adjustment bolts not being man enough to move an unbalanced load, they are aware of this but to fix it would require a major redesign so doubt it will happen anytime soon.

Dave

Have you used yours much in alt az mode Dave? I’ve got a 135 on order - one of reasons is to handle a front heavy solar Ha scope on camera tripod - will mainly use alt az for imaging and visual. But not many reports out there on alt az performance. 

[nfotis]

I read with interest the huge CN thread on this mount. It seems that you are required to use guiders, it doesn't work well otherwise.

The manufacturers seem to be making a hard effort to debug it (there are some "interesting" bugs with ASIair and meridian flipping, if memory serves me correctly).

I like the portability idea, but you have to watch out if you let it become too unbalanced - you cannot cheat physics, you need a good tripod and a large footprint.

Me, I think that I'll upgrade to an EQ6-R later from my HEQ5 Pro mount. It may be more pedestrian and heavy, but it's much cheaper.

N.F.

 

[Highburymark]

2 hours ago, nfotis said:

I read with interest the huge CN thread on this mount. It seems that you are required to use guiders, it doesn't work well otherwise.

The manufacturers seem to be making a hard effort to debug it (there are some "interesting" bugs with ASIair and meridian flipping, if memory serves me correctly).

I like the portability idea, but you have to watch out if you let it become too unbalanced - you cannot cheat physics, you need a good tripod and a large footprint.

Me, I think that I'll upgrade to an EQ6-R later from my HEQ5 Pro mount. It may be more pedestrian and heavy, but it's much cheaper.

N.F.

 

I read that thread too. I think there are still problems to be ironed out for eq imaging, but alt az seems to work well, and the capacity of the mount is incredible. My scopes are only 6-7kg fully laden, but one is very front heavy. I will add a counterweight as only using a camera tripod.  

[Ouroboros]

Pity these mounts are so pricey, though I must admit I am tempted. I see another one has just been bought from the FLO site, so they are selling at that price point.  I was rather hoping they’d come down in price. However, I think that might only happen if a competitor enters the market with this design of mount. 

I too have followed the CN thread. Some of the imaging results have been very good. 

As for guiding I see RainbowAstro are releasing an upgraded mount called the RST-135E with a Renishaw encoder on the RA axis which they claim provides +/-2.5 arcsecond periodic error for those “reluctant to use guiding”. Even pricier though at near on five and a half grand. Ouch! 

Edit: Added link http://www.rainbowastro.com/rst-135e-feature-eng/

Edited May 16, 2021 by Ouroboros

[Davey-T]

5 minutes ago, Ouroboros said:

I think that might only happen if a competitor enters the market with this design of mount. 

There are others like Crux but not any cheaper.

Dave

[Ouroboros]

9 minutes ago, Davey-T said:

There are others like Crux but not any cheaper.

Dave

Ah, yes. I was forgetting Crux. Perhaps if SkyWatcher or similar offered a similar product that might bring prices down. 

[nfotis]

2 hours ago, Ouroboros said:

Ah, yes. I was forgetting Crux. Perhaps if SkyWatcher or similar offered a similar product that might bring prices down. 

That would require sourcing robotic mechanisms, which are an altogether different market. And that would mean depending on another supplier (it's my understanding that Synta prefer to be vertically integrated as much as possible, in order to be able to control costs and quality themselves).

That makes me wondering: how much of the materials and parts in the Skywatcher mounts and telescopes are in-house designed and built?

N.F.