AP 400QMD and Solar Viewing


Alan
 

The 400 QMD is a fine match with our 80mm H-alpha scope. The Sun has recently recovered from its doldrums and there has been a lot to see. Aside from the wind, the weather has also been agreeable. 

Clear skies, Alan


Roland Christen
 

Nice to see someone doing visual ;^)

Rolando

-----Original Message-----
From: Alan <adfrench@...>
To: main@ap-ug.groups.io
Sent: Mon, Apr 26, 2021 4:03 pm
Subject: [ap-ug] AP 400QMD and Solar Viewing

The 400 QMD is a fine match with our 80mm H-alpha scope. The Sun has recently recovered from its doldrums and there has been a lot to see. Aside from the wind, the weather has also been agreeable. 

Clear skies, Alan


George
 

Roland, how can you be sure that he doesn’t have a camera hidden under there!    <G>

 

Regards,

 

George

 

George Whitney

Astro-Physics, Inc.

Phone:  815-222-6538 (direct line)

Phone:  815-282-1513 (office)

Email:  george@...

 

From: main@ap-ug.groups.io <main@ap-ug.groups.io> On Behalf Of Roland Christen via groups.io
Sent: Monday, April 26, 2021 5:16 PM
To: main@ap-ug.groups.io
Subject: Re: [ap-ug] AP 400QMD and Solar Viewing

 

Nice to see someone doing visual ;^)

 

Rolando

 

-----Original Message-----
From: Alan <adfrench@...>
To: main@ap-ug.groups.io
Sent: Mon, Apr 26, 2021 4:03 pm
Subject: [ap-ug] AP 400QMD and Solar Viewing

The 400 QMD is a fine match with our 80mm H-alpha scope. The Sun has recently recovered from its doldrums and there has been a lot to see. Aside from the wind, the weather has also been agreeable. 

Clear skies, Alan


Roland Christen
 

Ah, I never thought of that.

Roland



-----Original Message-----
From: George <george@...>
To: main@ap-ug.groups.io <main@ap-ug.groups.io>
Sent: Mon, Apr 26, 2021 5:21 pm
Subject: Re: [ap-ug] AP 400QMD and Solar Viewing

Roland, how can you be sure that he doesn’t have a camera hidden under there!    <G>
 
Regards,
 
George
 
George Whitney
Astro-Physics, Inc.
Phone:  815-222-6538 (direct line)
Phone:  815-282-1513 (office)
Email:  george@...
 
From: main@ap-ug.groups.io <main@ap-ug.groups.io> On Behalf Of Roland Christen via groups.io
Sent: Monday, April 26, 2021 5:16 PM
To: main@ap-ug.groups.io
Subject: Re: [ap-ug] AP 400QMD and Solar Viewing
 
Nice to see someone doing visual ;^)
 
Rolando
 
-----Original Message-----
From: Alan <adfrench@...>
To: main@ap-ug.groups.io
Sent: Mon, Apr 26, 2021 4:03 pm
Subject: [ap-ug] AP 400QMD and Solar Viewing
The 400 QMD is a fine match with our 80mm H-alpha scope. The Sun has recently recovered from its doldrums and there has been a lot to see. Aside from the wind, the weather has also been agreeable. 

Clear skies, Alan


Alan
 

That's Sue under the light shield, and I can guarantee no camera was involved. Ditto for my time under the hood.

Clear skies, Alan

On 4/26/2021 6:25 PM, Roland Christen via groups.io wrote:
Ah, I never thought of that.

Roland



-----Original Message-----
From: George <george@...>
To: main@ap-ug.groups.io <main@ap-ug.groups.io>
Sent: Mon, Apr 26, 2021 5:21 pm
Subject: Re: [ap-ug] AP 400QMD and Solar Viewing

Roland, how can you be sure that he doesn’t have a camera hidden under there!    <G>
 
Regards,
 
George
 
George Whitney
Astro-Physics, Inc.
Phone:  815-222-6538 (direct line)
Phone:  815-282-1513 (office)
Email:  george@...
 
From: main@ap-ug.groups.io <main@ap-ug.groups.io> On Behalf Of Roland Christen via groups.io
Sent: Monday, April 26, 2021 5:16 PM
To: main@ap-ug.groups.io
Subject: Re: [ap-ug] AP 400QMD and Solar Viewing
 
Nice to see someone doing visual ;^)
 
Rolando
 
-----Original Message-----
From: Alan <adfrench@...>
To: main@ap-ug.groups.io
Sent: Mon, Apr 26, 2021 4:03 pm
Subject: [ap-ug] AP 400QMD and Solar Viewing
The 400 QMD is a fine match with our 80mm H-alpha scope. The Sun has recently recovered from its doldrums and there has been a lot to see. Aside from the wind, the weather has also been agreeable. 

Clear skies, Alan


Christopher Erickson
 

Here is my Stowaway solar setup.

20210112_163723.jpg

"My advice is always free and worth every penny!"

-Christopher Erickson
Observatory Engineer
Summit Kinetics
Waikoloa, Hawaii


Virus-free. www.avg.com


On Mon, Apr 26, 2021 at 12:41 PM Alan <adfrench@...> wrote:
That's Sue under the light shield, and I can guarantee no camera was involved. Ditto for my time under the hood.

Clear skies, Alan

On 4/26/2021 6:25 PM, Roland Christen via groups.io wrote:
Ah, I never thought of that.

Roland



-----Original Message-----
From: George <george@...>
To: main@ap-ug.groups.io <main@ap-ug.groups.io>
Sent: Mon, Apr 26, 2021 5:21 pm
Subject: Re: [ap-ug] AP 400QMD and Solar Viewing

Roland, how can you be sure that he doesn’t have a camera hidden under there!    <G>
 
Regards,
 
George
 
George Whitney
Astro-Physics, Inc.
Phone:  815-222-6538 (direct line)
Phone:  815-282-1513 (office)
Email:  george@...
 
From: main@ap-ug.groups.io <main@ap-ug.groups.io> On Behalf Of Roland Christen via groups.io
Sent: Monday, April 26, 2021 5:16 PM
To: main@ap-ug.groups.io
Subject: Re: [ap-ug] AP 400QMD and Solar Viewing
 
Nice to see someone doing visual ;^)
 
Rolando
 
-----Original Message-----
From: Alan <adfrench@...>
To: main@ap-ug.groups.io
Sent: Mon, Apr 26, 2021 4:03 pm
Subject: [ap-ug] AP 400QMD and Solar Viewing
The 400 QMD is a fine match with our 80mm H-alpha scope. The Sun has recently recovered from its doldrums and there has been a lot to see. Aside from the wind, the weather has also been agreeable. 

Clear skies, Alan


Ross Elkins
 

Looks great Chris! I take it that Rainbow Astro mount had been working well for you on visual as well as some astrophotography? I see its on the CF tripod you talked about. I have been happy with the lighter version of the Artcise tripod so far for strictly manual with a cheap fluid head. Now Rainbow is advertising their latest including some sort of a polar alignment upgrade.
Ross


Christopher Erickson
 

First, this is an AP forum so I don't want to go into any depth about the Rainbow RST-135 here. There is a RainbowAstro Groups.io group for that. Or the several loooooong threads on Cloudy Nights.

I will say that I would have never purchased the RST-135 if AP had a lightweight travel mount perfectly matched to the Stowaway. I have had several discussions with Roland about this and he shared his concerns that a precision travel mount built to AP standards would be almost as expensive as the Mach1, which has (had) a lot more capacity. I was unable to convince him that I (and many others) would be willing to pay the price for "the world's most premium travel mount." Maybe if some others added their voices about this subject, we could convince him that a serious market exists for such an AP mount. 

Roland believes that AP's customers are most-all hard-core imagers (and serious, budding imagers) and I have been unable to convince him that there are several other significant AP customer profiles as well. 

One is the aging, financially-comfortable astronomer that needs/wants a premium mount and scope in a lightweight package and is losing enthusiasm (and muscle mass) for handling really big, heavy gear, and doesn't have an observatory, for various intractable reasons, like living in the city. These same astronomers drive a mid-to-premium car or truck. Not because they really need the handling, horsepower or 4WD, but simply because it gives them pleasure to own and handle quality items. I think this AP customer base is WAY BIGGER than anyone realizes. And they would really respond well to a smaller, lighter, feature-packed, high-quality mount.

Another profile, which fits me, is the astronomer that really needs to be portable. Either because they chase eclipses, chase occultations, or must go long distances by plane, train, boat or automobile to the places they wish to observe. Maybe it's a family vaycay and they need to keep their kit light and compact to make it possible at all. We need the utmost in reliability, quality and precision in a small, light package. For occultations and eclipses, periodic, random, and pseudo-random tracking error aren't as important as rigidity and reliability. Although I really like being able to do some casual astrophotography with my Nikon Z6 after an eclipse or occultation event.

There is a thread on Cloudy Nights titled "RainbowAstro RST-135 Review - The Ideal Imaging Mount?" and frankly I think the thread title is a bit silly. The RST-135 is a long, long way from the ideal imaging mount. I would give that title to the Mach2, hands-down. However it is definitely ideal in the category of "The Ultimate, All-Around, Quality, Rigid, Big-Capacity, Lightweight, Portable Mount That Can Also Do Casual Astrophotography And Even Serious Astrophotography, If You Have The Right Gear And Really Know What You Are Doing." I have been having a lot of fun with my RST-135 doing solar, visual and casual astrophotography. And admittedly it is way easier to pack to star-parties with my buddies than my Mach1 with 130EDF-GT or my 1100 with C14. And even though I can handle a C14 on an 1100 without any problems, the idea of using my Stowaway and the RST-135 just gives me more pleasure.

The RST-135 definitely brings back a bit of the magic I felt as a kid. Going out into the Dark with my little refractors and reflectors. All the pleasure and excitement without the time-consuming heft.

Personally, if I had a choice, I wouldn't be thrilled with a hybrid worm/harmonic drive mount. I know that from an engineering perspective it would work fine and be lighter and more compact than a mount design with dual-worm drives. However it just simply doesn't sound very appealing or tempting at all. To me it sounds about as sexy as a bikini swimsuit optimized for use with adult diapers. Ugh. Either make a portable mount with the world's most compact-yet-precision and rigid worm drives, or make a full-blown harmonic drive mount. If it had the AP logo and quality about it, I would buy it regardless.

I have been having loads of fun with my RST-135 and admittedly I haven't touched my Mach1 since it arrived.

One significant benefit of the RST-135 over all worm-drive mounts is the fact that the harmonic (strain-wave) drives NEVER need adjusting, regreasing or any other maintenance. Ever.

FWIW, putting the RST-135 on a rigid pier makes a world of difference.

I firmly believe that the future of amateur-class astronomy mounts is going to be strain-wave (harmonic) drives combined with precision absolute encoders. Encoders aren't there yet, in small size, in resolution and in cost, but they are getting closer every year.


"My advice is always free and worth every penny!"

-Christopher Erickson
Observatory Engineer
Summit Kinetics
Waikoloa, Hawaii


On Mon, Apr 26, 2021 at 1:25 PM Ross Elkins <rossmon1@...> wrote:
Looks great Chris! I take it that Rainbow Astro mount had been working well for you on visual as well as some astrophotography? I see its on the CF tripod you talked about. I have been happy with the lighter version of the Artcise tripod so far for strictly manual with a cheap fluid head.  Now Rainbow is advertising their latest including some sort of a polar alignment upgrade.
Ross






Virus-free. www.avg.com


Alex Langoussis
 

Christopher, I would be interested in knowing your solar set up on the Stowaway. Looks like a Coronado? Size? What adapters are required?  Have been thinking of getting an h-alpha setup for my Stowaway.

Thanks,
Alex


Christopher Erickson
 

Coronado single-stack 90. Precise Parts adapter. Great combination with the Stowaway!

And another note on compact mounts, it turns out that I don't miss clutches at all. Surprised myself.
 
"My advice is always free and worth every penny!"

-Christopher Erickson
Observatory Engineer
Summit Kinetics
Waikoloa, Hawaii


Virus-free. www.avg.com


On Mon, Apr 26, 2021 at 3:21 PM Alex Langoussis <astronomy@...> wrote:
Christopher, I would be interested in knowing your solar set up on the Stowaway. Looks like a Coronado? Size? What adapters are required?  Have been thinking of getting an h-alpha setup for my Stowaway.

Thanks,
Alex


Alex Langoussis
 

Christopher, what solar setup do you have attached to the Stowaway? Coronado? What adapters were involved? Thanks!

Alex




On Apr 26, 2021, at 4:04 PM, Christopher Erickson <christopher.k.erickson@...> wrote:


Here is my Stowaway solar setup.

<20210112_163723.jpg>


"My advice is always free and worth every penny!"

-Christopher Erickson
Observatory Engineer
Summit Kinetics
Waikoloa, Hawaii


Virus-free. www.avg.com

On Mon, Apr 26, 2021 at 12:41 PM Alan <adfrench@...> wrote:
That's Sue under the light shield, and I can guarantee no camera was involved. Ditto for my time under the hood.

Clear skies, Alan

On 4/26/2021 6:25 PM, Roland Christen via groups.io wrote:
Ah, I never thought of that.

Roland



-----Original Message-----
From: George <george@...>
To: main@ap-ug.groups.io <main@ap-ug.groups.io>
Sent: Mon, Apr 26, 2021 5:21 pm
Subject: Re: [ap-ug] AP 400QMD and Solar Viewing

Roland, how can you be sure that he doesn’t have a camera hidden under there!    <G>
 
Regards,
 
George
 
George Whitney
Astro-Physics, Inc.
Phone:  815-222-6538 (direct line)
Phone:  815-282-1513 (office)
Email:  george@...
 
From: main@ap-ug.groups.io <main@ap-ug.groups.io> On Behalf Of Roland Christen via groups.io
Sent: Monday, April 26, 2021 5:16 PM
To: main@ap-ug.groups.io
Subject: Re: [ap-ug] AP 400QMD and Solar Viewing
 
Nice to see someone doing visual ;^)
 
Rolando
 
-----Original Message-----
From: Alan <adfrench@...>
To: main@ap-ug.groups.io
Sent: Mon, Apr 26, 2021 4:03 pm
Subject: [ap-ug] AP 400QMD and Solar Viewing
The 400 QMD is a fine match with our 80mm H-alpha scope. The Sun has recently recovered from its doldrums and there has been a lot to see. Aside from the wind, the weather has also been agreeable. 

Clear skies, Alan


Roland Christen
 


I firmly believe that the future of amateur-class astronomy mounts is going to be strain-wave (harmonic) drives combined with precision absolute encoders. Encoders aren't there yet, in small size, in resolution and in cost, but they are getting closer every year.
We've been studying strain wave mounts and encoders for at least 6 years now, well before rainbow even thought about making one. There is no magic solution if you want high accuracy. We at AP decided to go down the path of high precision. This means precision encoders and accurate gears. Strain wave gears are not accurate, and even attaching a set of $5000 Renishaw absolute encoders will not produce sub-arc sec tracking. These gears wobble, and that cannot allow the encoders to produce their inherent sub-arc sec accuracy.

As far as seeing the cost of precision encoders come down - no that won't happen either. You can cut some cost by using a 2million tick encoder instead of a 67 million Renishaw. That means you have control down to the 5 arc sec level. But you get that inherently almost for free with a simple worm drive. Add PE correction and you are down to 1 arc sec. Renishaw makes cheaper encoders also, but what's the use of adding them if it doesn't produce accuracies any better than a simple worm?

Right now we have in the Mach2 and the larger encoder mounts a system that tracks very accurately to a small fraction of an arc second in RA. Recently Mike and I have been testing an adaptive loop control that can sense various parameters such as unbalance, heavy or light loads, belt tension, battery current capability, etc. and adjust itself automatically to achieve exactly what was ordered from an external command (i.e. a 1 arc sec guide command produces 1 arc sec shaft move in 1 shot in either axis, in same direction or in reversal). Add to that APCC Pro with its modeling and custom tracking, and you have essentially the ideal tracking platform for any size and focal length scope.

For example, you send a 0.1 arc sec command in either RA or Dec and the shaft moves by that amount. So, if you have really good seeing and a high performance scope, you can keep the guide star centroid to within this level on both axes. This includes reversing in Dec by that tiny amount in one command cycle in 1 second or less. A normal non-encoder mount might require 10 or more commands to reverse the Dec axis at sub-arc sec levels. It might go the wrong way at first due to stiction and exhibit retrograde motion for the first 5 reversal commands, and then it might finally reverse direction only to overshoot. Then the whole cycle repeats. Add to this a typical rough tracking in RA and yes, you will indeed have round stars but they will be 3 times fatter than they would be with an accurate tracking mount.

I would really hate to go backwards and build a low performance mount just to have a 6 pounder that I can put into a backpack. If we do make a small mount it will be light enough to be easy for anyone to move around, but it will have all the precision features that we have developed for the Mach2. I cannot chase every rainbow on the horizon, we have to make what we are good at making.

Rolando


-----Original Message-----
From: Christopher Erickson <christopher.k.erickson@...>
To: main@ap-ug.groups.io
Sent: Mon, Apr 26, 2021 8:13 pm
Subject: Re: [ap-ug] AP 400QMD and Solar Viewing

First, this is an AP forum so I don't want to go into any depth about the Rainbow RST-135 here. There is a RainbowAstro Groups.io group for that. Or the several loooooong threads on Cloudy Nights.

I will say that I would have never purchased the RST-135 if AP had a lightweight travel mount perfectly matched to the Stowaway. I have had several discussions with Roland about this and he shared his concerns that a precision travel mount built to AP standards would be almost as expensive as the Mach1, which has (had) a lot more capacity. I was unable to convince him that I (and many others) would be willing to pay the price for "the world's most premium travel mount." Maybe if some others added their voices about this subject, we could convince him that a serious market exists for such an AP mount. 

Roland believes that AP's customers are most-all hard-core imagers (and serious, budding imagers) and I have been unable to convince him that there are several other significant AP customer profiles as well. 

One is the aging, financially-comfortable astronomer that needs/wants a premium mount and scope in a lightweight package and is losing enthusiasm (and muscle mass) for handling really big, heavy gear, and doesn't have an observatory, for various intractable reasons, like living in the city. These same astronomers drive a mid-to-premium car or truck. Not because they really need the handling, horsepower or 4WD, but simply because it gives them pleasure to own and handle quality items. I think this AP customer base is WAY BIGGER than anyone realizes. And they would really respond well to a smaller, lighter, feature-packed, high-quality mount.

Another profile, which fits me, is the astronomer that really needs to be portable. Either because they chase eclipses, chase occultations, or must go long distances by plane, train, boat or automobile to the places they wish to observe. Maybe it's a family vaycay and they need to keep their kit light and compact to make it possible at all. We need the utmost in reliability, quality and precision in a small, light package. For occultations and eclipses, periodic, random, and pseudo-random tracking error aren't as important as rigidity and reliability. Although I really like being able to do some casual astrophotography with my Nikon Z6 after an eclipse or occultation event.

There is a thread on Cloudy Nights titled "RainbowAstro RST-135 Review - The Ideal Imaging Mount?" and frankly I think the thread title is a bit silly. The RST-135 is a long, long way from the ideal imaging mount. I would give that title to the Mach2, hands-down. However it is definitely ideal in the category of "The Ultimate, All-Around, Quality, Rigid, Big-Capacity, Lightweight, Portable Mount That Can Also Do Casual Astrophotography And Even Serious Astrophotography, If You Have The Right Gear And Really Know What You Are Doing." I have been having a lot of fun with my RST-135 doing solar, visual and casual astrophotography. And admittedly it is way easier to pack to star-parties with my buddies than my Mach1 with 130EDF-GT or my 1100 with C14. And even though I can handle a C14 on an 1100 without any problems, the idea of using my Stowaway and the RST-135 just gives me more pleasure.

The RST-135 definitely brings back a bit of the magic I felt as a kid. Going out into the Dark with my little refractors and reflectors. All the pleasure and excitement without the time-consuming heft.

Personally, if I had a choice, I wouldn't be thrilled with a hybrid worm/harmonic drive mount. I know that from an engineering perspective it would work fine and be lighter and more compact than a mount design with dual-worm drives. However it just simply doesn't sound very appealing or tempting at all. To me it sounds about as sexy as a bikini swimsuit optimized for use with adult diapers. Ugh. Either make a portable mount with the world's most compact-yet-precision and rigid worm drives, or make a full-blown harmonic drive mount. If it had the AP logo and quality about it, I would buy it regardless.

I have been having loads of fun with my RST-135 and admittedly I haven't touched my Mach1 since it arrived.

One significant benefit of the RST-135 over all worm-drive mounts is the fact that the harmonic (strain-wave) drives NEVER need adjusting, regreasing or any other maintenance. Ever.

FWIW, putting the RST-135 on a rigid pier makes a world of difference.

I firmly believe that the future of amateur-class astronomy mounts is going to be strain-wave (harmonic) drives combined with precision absolute encoders. Encoders aren't there yet, in small size, in resolution and in cost, but they are getting closer every year.


"My advice is always free and worth every penny!"

-Christopher Erickson
Observatory Engineer
Summit Kinetics
Waikoloa, Hawaii


On Mon, Apr 26, 2021 at 1:25 PM Ross Elkins <rossmon1@...> wrote:
Looks great Chris! I take it that Rainbow Astro mount had been working well for you on visual as well as some astrophotography? I see its on the CF tripod you talked about. I have been happy with the lighter version of the Artcise tripod so far for strictly manual with a cheap fluid head.  Now Rainbow is advertising their latest including some sort of a polar alignment upgrade.
Ross






Virus-free. www.avg.com


Bill Long
 

Well said! 🙂 


From: main@ap-ug.groups.io <main@ap-ug.groups.io> on behalf of Roland Christen via groups.io <chris1011@...>
Sent: Monday, April 26, 2021 6:50 PM
To: main@ap-ug.groups.io <main@ap-ug.groups.io>
Subject: Re: [ap-ug] AP 400QMD and Solar Viewing
 

I firmly believe that the future of amateur-class astronomy mounts is going to be strain-wave (harmonic) drives combined with precision absolute encoders. Encoders aren't there yet, in small size, in resolution and in cost, but they are getting closer every year.
We've been studying strain wave mounts and encoders for at least 6 years now, well before rainbow even thought about making one. There is no magic solution if you want high accuracy. We at AP decided to go down the path of high precision. This means precision encoders and accurate gears. Strain wave gears are not accurate, and even attaching a set of $5000 Renishaw absolute encoders will not produce sub-arc sec tracking. These gears wobble, and that cannot allow the encoders to produce their inherent sub-arc sec accuracy.

As far as seeing the cost of precision encoders come down - no that won't happen either. You can cut some cost by using a 2million tick encoder instead of a 67 million Renishaw. That means you have control down to the 5 arc sec level. But you get that inherently almost for free with a simple worm drive. Add PE correction and you are down to 1 arc sec. Renishaw makes cheaper encoders also, but what's the use of adding them if it doesn't produce accuracies any better than a simple worm?

Right now we have in the Mach2 and the larger encoder mounts a system that tracks very accurately to a small fraction of an arc second in RA. Recently Mike and I have been testing an adaptive loop control that can sense various parameters such as unbalance, heavy or light loads, belt tension, battery current capability, etc. and adjust itself automatically to achieve exactly what was ordered from an external command (i.e. a 1 arc sec guide command produces 1 arc sec shaft move in 1 shot in either axis, in same direction or in reversal). Add to that APCC Pro with its modeling and custom tracking, and you have essentially the ideal tracking platform for any size and focal length scope.

For example, you send a 0.1 arc sec command in either RA or Dec and the shaft moves by that amount. So, if you have really good seeing and a high performance scope, you can keep the guide star centroid to within this level on both axes. This includes reversing in Dec by that tiny amount in one command cycle in 1 second or less. A normal non-encoder mount might require 10 or more commands to reverse the Dec axis at sub-arc sec levels. It might go the wrong way at first due to stiction and exhibit retrograde motion for the first 5 reversal commands, and then it might finally reverse direction only to overshoot. Then the whole cycle repeats. Add to this a typical rough tracking in RA and yes, you will indeed have round stars but they will be 3 times fatter than they would be with an accurate tracking mount.

I would really hate to go backwards and build a low performance mount just to have a 6 pounder that I can put into a backpack. If we do make a small mount it will be light enough to be easy for anyone to move around, but it will have all the precision features that we have developed for the Mach2. I cannot chase every rainbow on the horizon, we have to make what we are good at making.

Rolando


-----Original Message-----
From: Christopher Erickson <christopher.k.erickson@...>
To: main@ap-ug.groups.io
Sent: Mon, Apr 26, 2021 8:13 pm
Subject: Re: [ap-ug] AP 400QMD and Solar Viewing

First, this is an AP forum so I don't want to go into any depth about the Rainbow RST-135 here. There is a RainbowAstro Groups.io group for that. Or the several loooooong threads on Cloudy Nights.

I will say that I would have never purchased the RST-135 if AP had a lightweight travel mount perfectly matched to the Stowaway. I have had several discussions with Roland about this and he shared his concerns that a precision travel mount built to AP standards would be almost as expensive as the Mach1, which has (had) a lot more capacity. I was unable to convince him that I (and many others) would be willing to pay the price for "the world's most premium travel mount." Maybe if some others added their voices about this subject, we could convince him that a serious market exists for such an AP mount. 

Roland believes that AP's customers are most-all hard-core imagers (and serious, budding imagers) and I have been unable to convince him that there are several other significant AP customer profiles as well. 

One is the aging, financially-comfortable astronomer that needs/wants a premium mount and scope in a lightweight package and is losing enthusiasm (and muscle mass) for handling really big, heavy gear, and doesn't have an observatory, for various intractable reasons, like living in the city. These same astronomers drive a mid-to-premium car or truck. Not because they really need the handling, horsepower or 4WD, but simply because it gives them pleasure to own and handle quality items. I think this AP customer base is WAY BIGGER than anyone realizes. And they would really respond well to a smaller, lighter, feature-packed, high-quality mount.

Another profile, which fits me, is the astronomer that really needs to be portable. Either because they chase eclipses, chase occultations, or must go long distances by plane, train, boat or automobile to the places they wish to observe. Maybe it's a family vaycay and they need to keep their kit light and compact to make it possible at all. We need the utmost in reliability, quality and precision in a small, light package. For occultations and eclipses, periodic, random, and pseudo-random tracking error aren't as important as rigidity and reliability. Although I really like being able to do some casual astrophotography with my Nikon Z6 after an eclipse or occultation event.

There is a thread on Cloudy Nights titled "RainbowAstro RST-135 Review - The Ideal Imaging Mount?" and frankly I think the thread title is a bit silly. The RST-135 is a long, long way from the ideal imaging mount. I would give that title to the Mach2, hands-down. However it is definitely ideal in the category of "The Ultimate, All-Around, Quality, Rigid, Big-Capacity, Lightweight, Portable Mount That Can Also Do Casual Astrophotography And Even Serious Astrophotography, If You Have The Right Gear And Really Know What You Are Doing." I have been having a lot of fun with my RST-135 doing solar, visual and casual astrophotography. And admittedly it is way easier to pack to star-parties with my buddies than my Mach1 with 130EDF-GT or my 1100 with C14. And even though I can handle a C14 on an 1100 without any problems, the idea of using my Stowaway and the RST-135 just gives me more pleasure.

The RST-135 definitely brings back a bit of the magic I felt as a kid. Going out into the Dark with my little refractors and reflectors. All the pleasure and excitement without the time-consuming heft.

Personally, if I had a choice, I wouldn't be thrilled with a hybrid worm/harmonic drive mount. I know that from an engineering perspective it would work fine and be lighter and more compact than a mount design with dual-worm drives. However it just simply doesn't sound very appealing or tempting at all. To me it sounds about as sexy as a bikini swimsuit optimized for use with adult diapers. Ugh. Either make a portable mount with the world's most compact-yet-precision and rigid worm drives, or make a full-blown harmonic drive mount. If it had the AP logo and quality about it, I would buy it regardless.

I have been having loads of fun with my RST-135 and admittedly I haven't touched my Mach1 since it arrived.

One significant benefit of the RST-135 over all worm-drive mounts is the fact that the harmonic (strain-wave) drives NEVER need adjusting, regreasing or any other maintenance. Ever.

FWIW, putting the RST-135 on a rigid pier makes a world of difference.

I firmly believe that the future of amateur-class astronomy mounts is going to be strain-wave (harmonic) drives combined with precision absolute encoders. Encoders aren't there yet, in small size, in resolution and in cost, but they are getting closer every year.


"My advice is always free and worth every penny!"

-Christopher Erickson
Observatory Engineer
Summit Kinetics
Waikoloa, Hawaii


On Mon, Apr 26, 2021 at 1:25 PM Ross Elkins <rossmon1@...> wrote:
Looks great Chris! I take it that Rainbow Astro mount had been working well for you on visual as well as some astrophotography? I see its on the CF tripod you talked about. I have been happy with the lighter version of the Artcise tripod so far for strictly manual with a cheap fluid head.  Now Rainbow is advertising their latest including some sort of a polar alignment upgrade.
Ross






Virus-free. www.avg.com


Roland Christen
 

Thanks. I know that there is a market for a very light weight mount, but then there is also a market for almost any gadget that you can think of. And the market for that light weight mount is being filled, apparently very successfully by Rainbow Astro. No real need for us to do the same.

Rolando

-----Original Message-----
From: Bill Long <bill@...>
To: main@ap-ug.groups.io <main@ap-ug.groups.io>
Sent: Mon, Apr 26, 2021 8:52 pm
Subject: Re: [ap-ug] AP 400QMD and Solar Viewing

Well said! 🙂 


From: main@ap-ug.groups.io <main@ap-ug.groups.io> on behalf of Roland Christen via groups.io <chris1011@...>
Sent: Monday, April 26, 2021 6:50 PM
To: main@ap-ug.groups.io <main@ap-ug.groups.io>
Subject: Re: [ap-ug] AP 400QMD and Solar Viewing
 

I firmly believe that the future of amateur-class astronomy mounts is going to be strain-wave (harmonic) drives combined with precision absolute encoders. Encoders aren't there yet, in small size, in resolution and in cost, but they are getting closer every year.
We've been studying strain wave mounts and encoders for at least 6 years now, well before rainbow even thought about making one. There is no magic solution if you want high accuracy. We at AP decided to go down the path of high precision. This means precision encoders and accurate gears. Strain wave gears are not accurate, and even attaching a set of $5000 Renishaw absolute encoders will not produce sub-arc sec tracking. These gears wobble, and that cannot allow the encoders to produce their inherent sub-arc sec accuracy.

As far as seeing the cost of precision encoders come down - no that won't happen either. You can cut some cost by using a 2million tick encoder instead of a 67 million Renishaw. That means you have control down to the 5 arc sec level. But you get that inherently almost for free with a simple worm drive. Add PE correction and you are down to 1 arc sec. Renishaw makes cheaper encoders also, but what's the use of adding them if it doesn't produce accuracies any better than a simple worm?

Right now we have in the Mach2 and the larger encoder mounts a system that tracks very accurately to a small fraction of an arc second in RA. Recently Mike and I have been testing an adaptive loop control that can sense various parameters such as unbalance, heavy or light loads, belt tension, battery current capability, etc. and adjust itself automatically to achieve exactly what was ordered from an external command (i.e. a 1 arc sec guide command produces 1 arc sec shaft move in 1 shot in either axis, in same direction or in reversal). Add to that APCC Pro with its modeling and custom tracking, and you have essentially the ideal tracking platform for any size and focal length scope.

For example, you send a 0.1 arc sec command in either RA or Dec and the shaft moves by that amount. So, if you have really good seeing and a high performance scope, you can keep the guide star centroid to within this level on both axes. This includes reversing in Dec by that tiny amount in one command cycle in 1 second or less. A normal non-encoder mount might require 10 or more commands to reverse the Dec axis at sub-arc sec levels. It might go the wrong way at first due to stiction and exhibit retrograde motion for the first 5 reversal commands, and then it might finally reverse direction only to overshoot. Then the whole cycle repeats. Add to this a typical rough tracking in RA and yes, you will indeed have round stars but they will be 3 times fatter than they would be with an accurate tracking mount.

I would really hate to go backwards and build a low performance mount just to have a 6 pounder that I can put into a backpack. If we do make a small mount it will be light enough to be easy for anyone to move around, but it will have all the precision features that we have developed for the Mach2. I cannot chase every rainbow on the horizon, we have to make what we are good at making.

Rolando


-----Original Message-----
From: Christopher Erickson <christopher.k.erickson@...>
To: main@ap-ug.groups.io
Sent: Mon, Apr 26, 2021 8:13 pm
Subject: Re: [ap-ug] AP 400QMD and Solar Viewing

First, this is an AP forum so I don't want to go into any depth about the Rainbow RST-135 here. There is a RainbowAstro Groups.io group for that. Or the several loooooong threads on Cloudy Nights.

I will say that I would have never purchased the RST-135 if AP had a lightweight travel mount perfectly matched to the Stowaway. I have had several discussions with Roland about this and he shared his concerns that a precision travel mount built to AP standards would be almost as expensive as the Mach1, which has (had) a lot more capacity. I was unable to convince him that I (and many others) would be willing to pay the price for "the world's most premium travel mount." Maybe if some others added their voices about this subject, we could convince him that a serious market exists for such an AP mount. 

Roland believes that AP's customers are most-all hard-core imagers (and serious, budding imagers) and I have been unable to convince him that there are several other significant AP customer profiles as well. 

One is the aging, financially-comfortable astronomer that needs/wants a premium mount and scope in a lightweight package and is losing enthusiasm (and muscle mass) for handling really big, heavy gear, and doesn't have an observatory, for various intractable reasons, like living in the city. These same astronomers drive a mid-to-premium car or truck. Not because they really need the handling, horsepower or 4WD, but simply because it gives them pleasure to own and handle quality items. I think this AP customer base is WAY BIGGER than anyone realizes. And they would really respond well to a smaller, lighter, feature-packed, high-quality mount.

Another profile, which fits me, is the astronomer that really needs to be portable. Either because they chase eclipses, chase occultations, or must go long distances by plane, train, boat or automobile to the places they wish to observe. Maybe it's a family vaycay and they need to keep their kit light and compact to make it possible at all. We need the utmost in reliability, quality and precision in a small, light package. For occultations and eclipses, periodic, random, and pseudo-random tracking error aren't as important as rigidity and reliability. Although I really like being able to do some casual astrophotography with my Nikon Z6 after an eclipse or occultation event.

There is a thread on Cloudy Nights titled "RainbowAstro RST-135 Review - The Ideal Imaging Mount?" and frankly I think the thread title is a bit silly. The RST-135 is a long, long way from the ideal imaging mount. I would give that title to the Mach2, hands-down. However it is definitely ideal in the category of "The Ultimate, All-Around, Quality, Rigid, Big-Capacity, Lightweight, Portable Mount That Can Also Do Casual Astrophotography And Even Serious Astrophotography, If You Have The Right Gear And Really Know What You Are Doing." I have been having a lot of fun with my RST-135 doing solar, visual and casual astrophotography. And admittedly it is way easier to pack to star-parties with my buddies than my Mach1 with 130EDF-GT or my 1100 with C14. And even though I can handle a C14 on an 1100 without any problems, the idea of using my Stowaway and the RST-135 just gives me more pleasure.

The RST-135 definitely brings back a bit of the magic I felt as a kid. Going out into the Dark with my little refractors and reflectors. All the pleasure and excitement without the time-consuming heft.

Personally, if I had a choice, I wouldn't be thrilled with a hybrid worm/harmonic drive mount. I know that from an engineering perspective it would work fine and be lighter and more compact than a mount design with dual-worm drives. However it just simply doesn't sound very appealing or tempting at all. To me it sounds about as sexy as a bikini swimsuit optimized for use with adult diapers. Ugh. Either make a portable mount with the world's most compact-yet-precision and rigid worm drives, or make a full-blown harmonic drive mount. If it had the AP logo and quality about it, I would buy it regardless.

I have been having loads of fun with my RST-135 and admittedly I haven't touched my Mach1 since it arrived.

One significant benefit of the RST-135 over all worm-drive mounts is the fact that the harmonic (strain-wave) drives NEVER need adjusting, regreasing or any other maintenance. Ever.

FWIW, putting the RST-135 on a rigid pier makes a world of difference.

I firmly believe that the future of amateur-class astronomy mounts is going to be strain-wave (harmonic) drives combined with precision absolute encoders. Encoders aren't there yet, in small size, in resolution and in cost, but they are getting closer every year.


"My advice is always free and worth every penny!"

-Christopher Erickson
Observatory Engineer
Summit Kinetics
Waikoloa, Hawaii


On Mon, Apr 26, 2021 at 1:25 PM Ross Elkins <rossmon1@...> wrote:
Looks great Chris! I take it that Rainbow Astro mount had been working well for you on visual as well as some astrophotography? I see its on the CF tripod you talked about. I have been happy with the lighter version of the Artcise tripod so far for strictly manual with a cheap fluid head.  Now Rainbow is advertising their latest including some sort of a polar alignment upgrade.
Ross






Virus-free. www.avg.com


DFisch
 

I have both the AP 400 and the RST 135 I love both.  The idea of a hybrid mount with a encoded RA  standard axis and a harmonic declination motor is a brilliant combination for me

On Mon, Apr 26, 2021 at 21:36 Christopher Erickson <christopher.k.erickson@...> wrote:
Coronado single-stack 90. Precise Parts adapter. Great combination with the Stowaway!

And another note on compact mounts, it turns out that I don't miss clutches at all. Surprised myself.
 
"My advice is always free and worth every penny!"

-Christopher Erickson
Observatory Engineer
Summit Kinetics
Waikoloa, Hawaii


Virus-free. www.avg.com

On Mon, Apr 26, 2021 at 3:21 PM Alex Langoussis <astronomy@...> wrote:
Christopher, I would be interested in knowing your solar set up on the Stowaway. Looks like a Coronado? Size? What adapters are required?  Have been thinking of getting an h-alpha setup for my Stowaway.

Thanks,
Alex

--
TJF MOBILE


Manusfisch
 

Rolando, as always great vision of end game, sign me up for one, Any combo that you can achieve that goal

TJF Mobile

On Apr 26, 2021, at 21:52, Bill Long <bill@...> wrote:


Well said! 🙂 


From: main@ap-ug.groups.io <main@ap-ug.groups.io> on behalf of Roland Christen via groups.io <chris1011@...>
Sent: Monday, April 26, 2021 6:50 PM
To: main@ap-ug.groups.io <main@ap-ug.groups.io>
Subject: Re: [ap-ug] AP 400QMD and Solar Viewing
 

I firmly believe that the future of amateur-class astronomy mounts is going to be strain-wave (harmonic) drives combined with precision absolute encoders. Encoders aren't there yet, in small size, in resolution and in cost, but they are getting closer every year.
We've been studying strain wave mounts and encoders for at least 6 years now, well before rainbow even thought about making one. There is no magic solution if you want high accuracy. We at AP decided to go down the path of high precision. This means precision encoders and accurate gears. Strain wave gears are not accurate, and even attaching a set of $5000 Renishaw absolute encoders will not produce sub-arc sec tracking. These gears wobble, and that cannot allow the encoders to produce their inherent sub-arc sec accuracy.

As far as seeing the cost of precision encoders come down - no that won't happen either. You can cut some cost by using a 2million tick encoder instead of a 67 million Renishaw. That means you have control down to the 5 arc sec level. But you get that inherently almost for free with a simple worm drive. Add PE correction and you are down to 1 arc sec. Renishaw makes cheaper encoders also, but what's the use of adding them if it doesn't produce accuracies any better than a simple worm?

Right now we have in the Mach2 and the larger encoder mounts a system that tracks very accurately to a small fraction of an arc second in RA. Recently Mike and I have been testing an adaptive loop control that can sense various parameters such as unbalance, heavy or light loads, belt tension, battery current capability, etc. and adjust itself automatically to achieve exactly what was ordered from an external command (i.e. a 1 arc sec guide command produces 1 arc sec shaft move in 1 shot in either axis, in same direction or in reversal). Add to that APCC Pro with its modeling and custom tracking, and you have essentially the ideal tracking platform for any size and focal length scope.

For example, you send a 0.1 arc sec command in either RA or Dec and the shaft moves by that amount. So, if you have really good seeing and a high performance scope, you can keep the guide star centroid to within this level on both axes. This includes reversing in Dec by that tiny amount in one command cycle in 1 second or less. A normal non-encoder mount might require 10 or more commands to reverse the Dec axis at sub-arc sec levels. It might go the wrong way at first due to stiction and exhibit retrograde motion for the first 5 reversal commands, and then it might finally reverse direction only to overshoot. Then the whole cycle repeats. Add to this a typical rough tracking in RA and yes, you will indeed have round stars but they will be 3 times fatter than they would be with an accurate tracking mount.

I would really hate to go backwards and build a low performance mount just to have a 6 pounder that I can put into a backpack. If we do make a small mount it will be light enough to be easy for anyone to move around, but it will have all the precision features that we have developed for the Mach2. I cannot chase every rainbow on the horizon, we have to make what we are good at making.

Rolando


-----Original Message-----
From: Christopher Erickson <christopher.k.erickson@...>
To: main@ap-ug.groups.io
Sent: Mon, Apr 26, 2021 8:13 pm
Subject: Re: [ap-ug] AP 400QMD and Solar Viewing

First, this is an AP forum so I don't want to go into any depth about the Rainbow RST-135 here. There is a RainbowAstro Groups.io group for that. Or the several loooooong threads on Cloudy Nights.

I will say that I would have never purchased the RST-135 if AP had a lightweight travel mount perfectly matched to the Stowaway. I have had several discussions with Roland about this and he shared his concerns that a precision travel mount built to AP standards would be almost as expensive as the Mach1, which has (had) a lot more capacity. I was unable to convince him that I (and many others) would be willing to pay the price for "the world's most premium travel mount." Maybe if some others added their voices about this subject, we could convince him that a serious market exists for such an AP mount. 

Roland believes that AP's customers are most-all hard-core imagers (and serious, budding imagers) and I have been unable to convince him that there are several other significant AP customer profiles as well. 

One is the aging, financially-comfortable astronomer that needs/wants a premium mount and scope in a lightweight package and is losing enthusiasm (and muscle mass) for handling really big, heavy gear, and doesn't have an observatory, for various intractable reasons, like living in the city. These same astronomers drive a mid-to-premium car or truck. Not because they really need the handling, horsepower or 4WD, but simply because it gives them pleasure to own and handle quality items. I think this AP customer base is WAY BIGGER than anyone realizes. And they would really respond well to a smaller, lighter, feature-packed, high-quality mount.

Another profile, which fits me, is the astronomer that really needs to be portable. Either because they chase eclipses, chase occultations, or must go long distances by plane, train, boat or automobile to the places they wish to observe. Maybe it's a family vaycay and they need to keep their kit light and compact to make it possible at all. We need the utmost in reliability, quality and precision in a small, light package. For occultations and eclipses, periodic, random, and pseudo-random tracking error aren't as important as rigidity and reliability. Although I really like being able to do some casual astrophotography with my Nikon Z6 after an eclipse or occultation event.

There is a thread on Cloudy Nights titled "RainbowAstro RST-135 Review - The Ideal Imaging Mount?" and frankly I think the thread title is a bit silly. The RST-135 is a long, long way from the ideal imaging mount. I would give that title to the Mach2, hands-down. However it is definitely ideal in the category of "The Ultimate, All-Around, Quality, Rigid, Big-Capacity, Lightweight, Portable Mount That Can Also Do Casual Astrophotography And Even Serious Astrophotography, If You Have The Right Gear And Really Know What You Are Doing." I have been having a lot of fun with my RST-135 doing solar, visual and casual astrophotography. And admittedly it is way easier to pack to star-parties with my buddies than my Mach1 with 130EDF-GT or my 1100 with C14. And even though I can handle a C14 on an 1100 without any problems, the idea of using my Stowaway and the RST-135 just gives me more pleasure.

The RST-135 definitely brings back a bit of the magic I felt as a kid. Going out into the Dark with my little refractors and reflectors. All the pleasure and excitement without the time-consuming heft.

Personally, if I had a choice, I wouldn't be thrilled with a hybrid worm/harmonic drive mount. I know that from an engineering perspective it would work fine and be lighter and more compact than a mount design with dual-worm drives. However it just simply doesn't sound very appealing or tempting at all. To me it sounds about as sexy as a bikini swimsuit optimized for use with adult diapers. Ugh. Either make a portable mount with the world's most compact-yet-precision and rigid worm drives, or make a full-blown harmonic drive mount. If it had the AP logo and quality about it, I would buy it regardless.

I have been having loads of fun with my RST-135 and admittedly I haven't touched my Mach1 since it arrived.

One significant benefit of the RST-135 over all worm-drive mounts is the fact that the harmonic (strain-wave) drives NEVER need adjusting, regreasing or any other maintenance. Ever.

FWIW, putting the RST-135 on a rigid pier makes a world of difference.

I firmly believe that the future of amateur-class astronomy mounts is going to be strain-wave (harmonic) drives combined with precision absolute encoders. Encoders aren't there yet, in small size, in resolution and in cost, but they are getting closer every year.


"My advice is always free and worth every penny!"

-Christopher Erickson
Observatory Engineer
Summit Kinetics
Waikoloa, Hawaii


On Mon, Apr 26, 2021 at 1:25 PM Ross Elkins <rossmon1@...> wrote:
Looks great Chris! I take it that Rainbow Astro mount had been working well for you on visual as well as some astrophotography? I see its on the CF tripod you talked about. I have been happy with the lighter version of the Artcise tripod so far for strictly manual with a cheap fluid head.  Now Rainbow is advertising their latest including some sort of a polar alignment upgrade.
Ross






Virus-free. www.avg.com


Manusfisch
 

Chris I have the same setup w np101is, less portable. Will you share the dimensions of your adapter for the Coronado etalon and the stowaway 92 Lens cell?

TJF Mobile

On Apr 26, 2021, at 19:04, Christopher Erickson <christopher.k.erickson@...> wrote:


Here is my Stowaway solar setup.

20210112_163723.jpg

"My advice is always free and worth every penny!"

-Christopher Erickson
Observatory Engineer
Summit Kinetics
Waikoloa, Hawaii


Virus-free. www.avg.com

On Mon, Apr 26, 2021 at 12:41 PM Alan <adfrench@...> wrote:
That's Sue under the light shield, and I can guarantee no camera was involved. Ditto for my time under the hood.

Clear skies, Alan

On 4/26/2021 6:25 PM, Roland Christen via groups.io wrote:
Ah, I never thought of that.

Roland



-----Original Message-----
From: George <george@...>
To: main@ap-ug.groups.io <main@ap-ug.groups.io>
Sent: Mon, Apr 26, 2021 5:21 pm
Subject: Re: [ap-ug] AP 400QMD and Solar Viewing

Roland, how can you be sure that he doesn’t have a camera hidden under there!    <G>
 
Regards,
 
George
 
George Whitney
Astro-Physics, Inc.
Phone:  815-222-6538 (direct line)
Phone:  815-282-1513 (office)
Email:  george@...
 
From: main@ap-ug.groups.io <main@ap-ug.groups.io> On Behalf Of Roland Christen via groups.io
Sent: Monday, April 26, 2021 5:16 PM
To: main@ap-ug.groups.io
Subject: Re: [ap-ug] AP 400QMD and Solar Viewing
 
Nice to see someone doing visual ;^)
 
Rolando
 
-----Original Message-----
From: Alan <adfrench@...>
To: main@ap-ug.groups.io
Sent: Mon, Apr 26, 2021 4:03 pm
Subject: [ap-ug] AP 400QMD and Solar Viewing
The 400 QMD is a fine match with our 80mm H-alpha scope. The Sun has recently recovered from its doldrums and there has been a lot to see. Aside from the wind, the weather has also been agreeable. 

Clear skies, Alan


Alan
 

Rolando,

Sounds like the perfect plan. Please do.

Clear skies, Alan

On 4/26/2021 9:50 PM, Roland Christen via groups.io wrote: In Part....


I would really hate to go backwards and build a low performance mount just to have a 6 pounder that I can put into a backpack. If we do make a small mount it will be light enough to be easy for anyone to move around, but it will have all the precision features that we have developed for the Mach2. I cannot chase every rainbow on the horizon, we have to make what we are good at making.

Rolando


Moshen Chan
 

I'm really enjoying the RST-135 for travel but I would definitely buy a smaller Mach2.

Moshen


On Mon, Apr 26, 2021 at 6:50 PM Roland Christen via groups.io <chris1011=aol.com@groups.io> wrote:

I would really hate to go backwards and build a low performance mount just to have a 6 pounder that I can put into a backpack. If we do make a small mount it will be light enough to be easy for anyone to move around, but it will have all the precision features that we have developed for the Mach2. I cannot chase every rainbow on the horizon, we have to make what we are good at making.

Rolando


alan.dang@...
 

One of the other things about the RST-135 which isn’t  on only discussed is how the polar alignment knobs are finicky and wear down with time and how there are exposed ports that face upwards toward the sky which has some risks with dew.

What would an EM-11 class AP mount look like?  Wouldn’t CNC techniques instead of sandcasted parts be lighter, not to mention the advances with AP software?  Or is this a niche that is already served with the EM-11?

What about Vixen’s motors-as-counterweight approach to reduce the size of the counterweights even though the mount is the same weight?