Date   

Re: Greasing/maintaining mounts

Luca Marinelli
 

Thank you, Roland!

Luca


Re: A tulip and a black hole

Arun
 

A very pretty tulip imaged though a very pretty scope. 


On Thu, Jun 23, 2022 at 01:14 PM, KHursh wrote:
https://astrob.in/7v58ix/0/

 

 


Re: Greasing/maintaining mounts

Roland Christen
 

PEC curve (or periodic error) is not a function of the worm wheel. So no matter where you are on the worm wheel, the periodic error is the same. It is the worm gear (the driving gear), not the worm wheel (the driven gear) that produces the period error.

Roland

-----Original Message-----
From: Luca Marinelli <photo@...>
To: main@ap-ug.groups.io <main@ap-ug.groups.io>
Sent: Thu, Jun 23, 2022 4:23 pm
Subject: Re: [ap-ug] Greasing/maintaining mounts

Does the procedure to use the other half of the worm wheel requires creating a fresh PEC curve?

Luca





Re: Greasing/maintaining mounts

Luca Marinelli
 

Does the procedure to use the other half of the worm wheel requires creating a fresh PEC curve?

Luca


Re: Greasing/maintaining mounts

midmoastro
 

I might also add these wise words, also found in the manual.

"Using the entire worm wheel ensures even wear and extended life. Under normal use the mount moves back and forth using only one half of the worm wheel...the other half is not used.

Here’s what to do: Send the mount to Park 1, unlock the clutches and push the mount to Park 4. Lock the clutches and then power cycle the mount (power off and then on). Tell the mount to resume from Park 4. The mount will then be using

the other half of the worm wheel.

Note that it will be necessary to have the Keypad set to AutoConnect=NO (if initializing with the Keypad) or to set the AP V2 driver / APCC (if initializing from the computer) to Unpark from Park 4. Once this operation is done remember to reset to Unpark from Last Parked.

Do it twice a year...that should be enough."


Re: Greasing/maintaining mounts

Roland Christen
 

All our mounts have spring loaded worms which means they are 100% in mesh at all times. If you are pushing on the end of the counterweight shaft and can feel some springiness on the end of the shaft, all that means is you are using the huge leverage of the cwt shaft to push the worm teeth apart against the spring action. As soon as you let go, the worm teeth will settle back into full mesh. The amount of leverage is about 10:1 at the end of the cwt shaft. This means a 1 lb force from your hand exerts 10lb of force trying to push the worm teeth apart.

The amount that the worm teeth can be pushed apart is limited by the backstop, so even if you apply 100lb force on the shaft, the worm teeth can only be pushed back by a few thousandth of an inch, which is the point where the pivot mechanism hits the backstop. You can decrease the backstop distance a bit, but I would not recommend it. Too little clearance can cause the teeth to bottom out at some point (a high point) on the gearwheel and cause excessive wear.

You want to be sure that you are differentiating what you call looseness with the actual spring loading feel at the end of the cwt shaft. true looseness or also known as backlash would allow you to move the counterweight shaft back and forth with just the application of a feather. Take your finger and thumb and place it on the shaft and apply the tiniest amount of pressure. If you can feel looseness or backlash, then that is an indication of something else. However, backlash in RA has zero effect on tracking or guiding, since it only comes into play when the axis is reversed, and that never happens during tracking and guiding. So, again I would leave it alone and don't try to re-adjust anything without specific guidance from one of our techs here at AP. A slightly loose axis will track perfectly, a slightly tight one will not.

Roland Christen
Astro-Physics Inc.



-----Original Message-----
From: Hy Murveit <murveit@...>
To: main@ap-ug.groups.io
Sent: Thu, Jun 23, 2022 1:39 pm
Subject: [ap-ug] Greasing/maintaining mounts

I bought a used AP-1100/CP3 in December and have been happily using it with my 10" GSO RC (and with INDI/KStars!).

I was wondering, is there any recommended maintenance for the mount, e.g. should I be greasing it from time to time? 

I think the RA axis is a little looser than DEC, is there an adjustment screw for the backlash there?

Thanks,
Hy


Greasing/maintaining mounts

Hy Murveit
 

I bought a used AP-1100/CP3 in December and have been happily using it with my 10" GSO RC (and with INDI/KStars!).

I was wondering, is there any recommended maintenance for the mount, e.g. should I be greasing it from time to time? 

I think the RA axis is a little looser than DEC, is there an adjustment screw for the backlash there?

Thanks,
Hy


Re: Two Solstice Transits

Alan Friedman
 

Thanks very much Chris.

I’ve attached a photo of my case for the Stowaway which also carries my Ha solar gear. It’s remarkable compact. In here are the telescope and Coronado 90 etalon, 2” straight through blocking filter, mounting ring (standing in front but stows on top of the etalon at lower left), 1.25 mirror diagonal, zoom eyepiece, three streaming cameras + 1.25” nosepieces, Baader FFC, 2X Powermate, two extension tubes and cables to attach to various Mac computers. Phew!

The etalon screws to the tilting mechanism (black part) which is attached to an A-P traveler mounting ring. The latter was sold by Coronado at the time and for years I used the Coronado 90 on the traveler. The magical mating piece can be seen attached to the front of the Stowaway. It is a spare traveler tube ring purchased from A-P when I got the Stowaway. Its inside diameter is a perfect fit to the dew shield of the stowaway and the outside diameter is the same as the traveler dew shield, so the original mounting ring fits on it perfectly. The stowaway dew shield rotates which allows a subtle tilt change to the etalon - finer than the tilt achieved by the tilting mechanism. This rotation allows me to adjust the bandwidth with a good degree of precision and yields an evenly lit field of view across the entire disk of the sun at 900mm focal length. The 92mm aperture of the stowaway is a perfect match to the Coronado 90. A larger telescope could provide the same magnification without the use of the Powermate, but it would put the etalon much further away and make adjusting the bandwidth while viewing the result on a computer screen much more difficult. 

I’ve attached a photo of Ha stowaway (I call him Little Big Man) on my 1200 mount. There is a lovely 10” scope mounted in between in this photo but normally I have 6” tube rings on the mount and the Stowaway ride on a plate atop the 6” rings. 

Cheers!
Alan



On Jun 22, 2022, at 7:17 PM, Chris White <chris.white@...> wrote:

Wow!  Really amazing Alan!  Spectacular details on the disk and the ISS.  Soooo... coool.

How do you attach the coronado filter?  Do you have a picture of your setup?  I dabbled with solar with a lunt50 years ago, but the image circle was pretty small and the focal length was pretty short.  I've thought about doing it with my stowaway .  Thanks in advance!


Re: Two Solstice Transits

Alan Friedman
 

Hi Konstantin,

Thank you for your comments and questions. 

As you’ve guessed, the image is a combination of data. The sun detail results from a stack of 300 or so sharpest frames from a video stream of 1600 frames. These 300 frames are aligned using 130 points across the disk and stacked to permit further processing than would otherwise be possible given the noise in the individual frames. The camera I use is an older Point Grey Grasshopper Xpress. It’s a 6mp sensor that can capture the full disk of the sun at 900mm, which I achieve using the f4.9 Stowaway with a 2X Powermate. This firewire camera has a maximum rate of 12 frames/second in 8 bit mode. That yields 6 frames with the ISS on a typical pass. Of these, 4 were less than optimal and one showed the ISS directly over the beautiful active region at upper right. The sixth was nice and sharp and in a quiet region of the chromosphere. The data from this frame was incorporated into the stacked data to create the final result. Likewise, the exposures for disk and prominences are different so these components are recorded separately and then combined to make the finished image.

The seeing was quite good at times but far from perfect and the wind was very strong. After setting up I had to pick up the rig and move it alongside a tree! 900mm is a forgiving focal length. The hardest part of imaging the sun over a field this wide is attaining an even hydrogen alpha band. Rotating the etalon using the dew shield of the Stowaway helps to fine tune the bandwidth and to keep the brightness even across a wide field. Hydrogen Alpha filters are a little like violins, no two play exactly the same. I’m fortunate to have gotten a sweet one that has held up well over two decades. 

Clear skies,
Alan
 



On Jun 23, 2022, at 3:11 AM, Konstantin von Poschinger <KPoschinger@...> wrote:

Hi Alan,

thanks for sharing this stunning images. Can you tell how you menage to get such a sharp H-Alpha sun with the ISS in a one shot image. The seeing conditions must have been absolutely superb. Or is this image a result of adding multiple images with one that has the iss in it. 
I would like to see your setup. 

Grüsse

Konstantin

Konstantin v. Poschinger


Hammerichstr. 5
22605 Hamburg
040/8805747
0171/1983476

Am 23.06.2022 um 00:47 schrieb Alan Friedman <alan@...>:

Hi all,

I brought my f5 Stowaway and 400 mount about 10 miles from home yesterday for a meet-up with the sun and the ISS. It was an adventure I’ve done before - most recently on June 21, 2020, exactly two years ago. I had pretty good conditions both times.

The space station looks pretty much the same as it did two years ago. Our Sun was a different story altogether which moved me to do a comparison of the two captures side by side. Two years ago we were still in the depths of solar minimum. Yesterday the sun sported a bunch of active regions, large filaments - even a fast moving exploding prominence to welcome the 1/2 second flyby of the space station’s dragonfly silhouette.

Hope you enjoy the sunshine!





Best wishes,
Alan
 





Re: A tulip and a black hole

Roland Christen
 

Certainly is a beautiful result.

Rolando

-----Original Message-----
From: KHursh via groups.io <khursh@...>
To: main@ap-ug.groups.io
Sent: Thu, Jun 23, 2022 12:14 pm
Subject: [ap-ug] A tulip and a black hole

[Edited Message Follows]
Hey folks,


I am just starting to image a little with the stowaway from home. I got 23 hours on the tulip and I swear I should've gotten 30. Also, I am new to SHO processing, so be gentle. Thanks for looking!

https://astrob.in/7v58ix/0/


Re: A tulip and a black hole

Karen Christen
 

Looks like a very nice result, Kevin.  I like it a lot!

Karen

AP

 

From: main@ap-ug.groups.io <main@ap-ug.groups.io> On Behalf Of KHursh via groups.io
Sent: Thursday, June 23, 2022 12:14 PM
To: main@ap-ug.groups.io
Subject: [ap-ug] A tulip and a black hole

 

[Edited Message Follows]

Hey folks,

I am just starting to image a little with the stowaway from home. I got 23 hours on the tulip and I swear I should've gotten 30. Also, I am new to SHO processing, so be gentle. Thanks for looking!

https://astrob.in/7v58ix/0/


A tulip and a black hole

KHursh
 
Edited

Hey folks,

I am just starting to image a little with the stowaway from home. I got 23 hours on the tulip and I swear I should've gotten 30. Also, I am new to SHO processing, so be gentle. Thanks for looking!

https://astrob.in/7v58ix/0/


Re: Two Solstice Transits

Alan Friedman
 

Many thanks to all for your nice comments… happy to hear them. I will write back shortly to the technical questions (busy morning!)

Clear skies and best wishes,
Alan




On Jun 23, 2022, at 1:06 AM, Emilio J. Robau, P.E. <ejr@...> wrote:

Alan,

These images are a great inspiration to all of us.  Absolutely stunning.  I am for sure going to check out some solar imaging with the Stowaway.  Thank you for the post.

They brought me out of a lurking period.



Re: Two Solstice Transits

Ray
 

Wow just WOW!!! Love it.  Makes me think to sell my PST and buy an H-Alpha Solar filter for my Stowaway


Re: Two Solstice Transits

Konstantin von Poschinger
 

Hi Alan,

thanks for sharing this stunning images. Can you tell how you menage to get such a sharp H-Alpha sun with the ISS in a one shot image. The seeing conditions must have been absolutely superb. Or is this image a result of adding multiple images with one that has the iss in it. 
I would like to see your setup. 

Grüsse

Konstantin

Konstantin v. Poschinger


Hammerichstr. 5
22605 Hamburg
040/8805747
0171/1983476

Am 23.06.2022 um 00:47 schrieb Alan Friedman <alan@...>:

Hi all,

I brought my f5 Stowaway and 400 mount about 10 miles from home yesterday for a meet-up with the sun and the ISS. It was an adventure I’ve done before - most recently on June 21, 2020, exactly two years ago. I had pretty good conditions both times.

The space station looks pretty much the same as it did two years ago. Our Sun was a different story altogether which moved me to do a comparison of the two captures side by side. Two years ago we were still in the depths of solar minimum. Yesterday the sun sported a bunch of active regions, large filaments - even a fast moving exploding prominence to welcome the 1/2 second flyby of the space station’s dragonfly silhouette.

Hope you enjoy the sunshine!





Best wishes,
Alan
 




Re: Two Solstice Transits

R Botero
 

Just beautiful Alan!👍

Roberto


Re: Two Solstice Transits

Emilio J. Robau, P.E.
 

Alan,

These images are a great inspiration to all of us.  Absolutely stunning.  I am for sure going to check out some solar imaging with the Stowaway.  Thank you for the post.

They brought me out of a lurking period.


Re: 110 scope musings

Roland Christen
 


"A digital focusing system will be available for imaging".
Feathertouch sells one that bolts right on.

Roland

-----Original Message-----
From: Dan Folz via groups.io <dfolz75@...>
To: main@ap-ug.groups.io <main@ap-ug.groups.io>
Sent: Wed, Jun 22, 2022 9:31 pm
Subject: Re: [ap-ug] 110 scope musings

Speaking of the new scope, I was reading its description on the website again. Towards the end I read the following:
"A digital focusing system will be available for imaging".
What might that consist of?

My best,
Dan Folz
On Wednesday, June 22, 2022, 08:45:50 PM CDT, Chris White <chris.white@...> wrote:


On Wed, Jun 22, 2022 at 09:33 PM, Dean Jacobsen wrote:
Yeah, I wouldn’t expect it to given my experience with my FSQ-106 and my APS-C camera at f/5.  Interestingly, I just purchased an ASI2400MC full frame OSC camera (5.94 micron pixels) for wide field shots this summer but haven’t had a chance to use it yet. I had planned to use it with the FSQ and the f/3.6 645 reducer but I do want to try a couple of tests at f/5 also and see how well the larger pixels cover up the chromatic aberration… if that is the proper term for the star shapes going wonky at the corners.
--
Dean Jacobsen 
Astrobin: https://www.astrobin.com/users/deanjacobsen/ 

That will be an interesting test.  I wonder at what pixel size optical correction becomes orders of magnitudes more difficult. 

I'm not sure what the phenomenon is that I see on the FSQ106.   It looks like stars are half gold and half blue.  Is that CA? Stars are also not perfectly round, but have some edge aberration.  

Also, for those reading, I'm not trashing the fsq106.  There are a number of imagers whom I have great respect for that produce incredible work with that scope... I'm just giving my unvarnished critique of the scope's performance.  I think a big part of the problem with the 106 is that the petzval design they use is susceptible to miscollimation after being banged around (maybe in shipping?).  That's another thing AP does right with scopes, it seems they are very tolerant of being handled roughly.  The lenses stay put.  I spent about two years considering the fsq106.  Bill Long convinced me to keep considering it while looking for a 130GTX.    I'm fortunate that a 130 ended up finding me.  


Re: 110 scope musings

Roland Christen
 

How big (length and width) and heavy is it and will it fit in the overhead? Will it truly cover a full frame CMOS imager without lateral color in the corners?

Rolando

-----Original Message-----
From: Steve Armen <st5.armen@...>
To: main@ap-ug.groups.io
Sent: Wed, Jun 22, 2022 6:35 pm
Subject: Re: [ap-ug] 110 scope musings

I know the optical design is not the same, however ...

FSQ106edx4 specs:

Aperture: 106mm
Focal length at native f/5: 530mm
Image circle: 88mm
Back distance: 178mm

On Wed, Jun 22, 2022 at 4:20 PM James Stone via groups.io <jrs7r=virginia.edu@groups.io> wrote:
The 110 is pretty clearly differentiated from other wide field refractor offerings and will serve a presently unmet need.


On Jun 22, 2022, at 7:17 PM, Steve Armen <st5.armen@...> wrote:


For imaging use in the market today, I don't see the need for another premium fast widefield (relatively short focal length) refractor. There are many available that perform wonderfully. Personally I would much prefer f/6 to f/7 with a flattener only. I feel that would be a more unique offering. Just my opinion, worth the paper it is printed on :-)

On Wed, Jun 22, 2022 at 2:10 PM Chris White <chris.white@...> wrote:
On Wed, Jun 22, 2022 at 03:46 PM, Roland Christen wrote:
Right now we have an optional TCC that produces F5 focal ratio for the full frame CMOS cameras. I have some designs for a flattener but have not made a final determination as to the focal ratio. Making it F6 would seem to be too close to the F5 TCC. Perhaps making it somewhat longer would fulfill a need? Lot of scopes now on the market are running at F7 or a bit longer. Is that ideal?
 
Roland
Thats a good question, and I don't know if there is one answer.  I'm strictly an imager, and for me you've already achieved what would be most important to me.  Fast and wide.  550mm FL at f5 with an IMX455 chip is pretty much the panacea for widefield/high resolution imaging. 

If I was looking for one scope to do it all, perhaps the 110 with an f5 reducer and an f7 flattener would be the best way to go.  I tend to agree that f6 would be too close to f5, I'm not sure where the incentive would be to have both a reducer and n f6 flattener.

I guess I think that the flattener for this scope is icing on the cake, but what really makes it special is the reducer (from an imaging perspective). 

I already have a 130GTX with the flattener, so perhaps that shapes my viewpoint. 

A superfast, widefield imaging BEAST is what the 110 screams, in my opinion.  F5!


Re: Two Solstice Transits

Greg Vaughn
 

Hi Alan,

 

As others have commented, your images are superb!   An inspiration to me, in particular, to pursue solar imaging past the stage of imaging just the sunspots with a Baader filter on my telescope.

 

The ISS is so sharp and the chrominance and prominences are also so well defined and sharp - it all combines to be a very impressive image.

 

The comparison between this year and last year is very telling.    There was a period last year that I didn’t even check the sunspots, knowing there would be nothing to see.   Now, the Sun is rich with sunspots – and I’d sure like to be able to image in a similar manner.

 

Again, WOW!  Nice work.   Thanks for sharing!

 

Cheers,

Greg

 

p.s. I have chosen to get the collections of posts and feel that I’m a little late to the party – apologize for any duplication, but I also wanted to make sure I said how much I enjoyed these images!

 

Greg Vaughn

Alexandria, VA


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