Date   

Re: Crayford style focuser for Vario-Finder 10x60 ; 61x250 f/4.1

George
 

It works great.

 

Regards,

 

George

 

George Whitney

Astro-Physics, Inc.

Phone:  815-222-6538 (direct line)

Phone:  815-282-1513 (office)

Email:  george@...

 

From: main@ap-gto.groups.io <main@ap-gto.groups.io> On Behalf Of CurtisC via groups.io
Sent: Thursday, October 15, 2020 3:55 PM
To: main@ap-gto.groups.io
Subject: Re: [ap-gto] Crayford style focuser for Vario-Finder 10x60 ; 61x250 f/4.1

 

George, what do you think of the Baader Vario-Finder for guiding?  I know in 2013 you seemed to have some success with it.  What have seven years of experience taught you?


Re: Crayford style focuser for Vario-Finder 10x60 ; 61x250 f/4.1

CurtisC
 

George, what do you think of the Baader Vario-Finder for guiding?  I know in 2013 you seemed to have some success with it.  What have seven years of experience taught you?


Re: Crayford style focuser for Vario-Finder 10x60 ; 61x250 f/4.1

George
 

Guys,

 

Use the Baader scope’s fine focus, not a helical focuser…flexure can enter into the guiding.    The point of the guidescope design was to eliminate all flexure.

 

Regards,

 

George

 

George Whitney

Astro-Physics, Inc.

Phone:  815-222-6538 (direct line)

Phone:  815-282-1513 (office)

Email:  george@...

 

From: main@ap-gto.groups.io <main@ap-gto.groups.io> On Behalf Of Robert Berta
Sent: Thursday, October 15, 2020 3:31 PM
To: main@ap-gto.groups.io
Subject: Re: [ap-gto] Crayford style focuser for Vario-Finder 10x60 ; 61x250 f/4.1

 

Huetech used to sell a nice helical focuser that didn't rotate the camera. You can lock down all of the adjustments with thumb screws so once locked down there is NO flexure or unwanted movement. I have had that setup (with a 50mm guide scope) since about 2005 and it works great with my 152mm and 80mm APO refractors. I have another 70mm guide scope with a longer focal length  and different focuser that I use with both the 152mm APO refractor and a 11" SCT. The trick is to eliminate ALL possible loose/soft connections....once you do you will get great guiding. 

I don't have the part number of that Huetech focuser anymore so can't help there. 


Re: Crayford style focuser for Vario-Finder 10x60 ; 61x250 f/4.1

 

>>> "Guiding Assistant" in PHD or PHD2?


PHD2


On Thu, Oct 15, 2020 at 1:39 PM CurtisC via groups.io <calypte=verizon.net@groups.io> wrote:
Thank you, Rolando.

"Guiding Assistant" in PHD or PHD2?

I've reviewed most of what you've posted about guiding in this forum, going back two decades.  That's not to say that maybe I haven't missed something important.  In the past I ignored the Advanced Settings in MaxImDL  I never looked at them.  I got what I got.  Having studied your advice, I believe my results have noticeably improved on nights of good seeing.  It's the nights of bad seeing, like the last few nights, that still trouble me.  Fiddling with the Min Move and aggressiveness, I've been able to get good results (= approximately round stars) on NGC 7293, which -- even for me at 33.5 deg N -- is pretty far south.  But guiding on something straight overhead, like M33, has been less successful.  That's where I ordinarily expect the best results.  So I'm still trying to get things worked out on nights of bad seeing.  As we speak, I'm still using the QSI's OAG.  But I may go back to using the Baader Vario-Finder again.  There are always guide stars, and I don't have to recalibrate if I rotate the QSI from landscape to portrait orientation.  But I assume the Min Move has to be increased significantly.



--
Brian 



Brian Valente


Re: Crayford style focuser for Vario-Finder 10x60 ; 61x250 f/4.1

CurtisC
 

Thank you, Rolando.

"Guiding Assistant" in PHD or PHD2?

I've reviewed most of what you've posted about guiding in this forum, going back two decades.  That's not to say that maybe I haven't missed something important.  In the past I ignored the Advanced Settings in MaxImDL  I never looked at them.  I got what I got.  Having studied your advice, I believe my results have noticeably improved on nights of good seeing.  It's the nights of bad seeing, like the last few nights, that still trouble me.  Fiddling with the Min Move and aggressiveness, I've been able to get good results (= approximately round stars) on NGC 7293, which -- even for me at 33.5 deg N -- is pretty far south.  But guiding on something straight overhead, like M33, has been less successful.  That's where I ordinarily expect the best results.  So I'm still trying to get things worked out on nights of bad seeing.  As we speak, I'm still using the QSI's OAG.  But I may go back to using the Baader Vario-Finder again.  There are always guide stars, and I don't have to recalibrate if I rotate the QSI from landscape to portrait orientation.  But I assume the Min Move has to be increased significantly.


Re: Crayford style focuser for Vario-Finder 10x60 ; 61x250 f/4.1

 

zwo also sells a helical non-rotating focuser, I'm not sure if it meets your specs

I think i have one of those hutech helical focusers i'm not using if that's the path you choose


Brian

On Thu, Oct 15, 2020 at 1:31 PM Robert Berta <biker123@...> wrote:
Huetech used to sell a nice helical focuser that didn't rotate the camera. You can lock down all of the adjustments with thumb screws so once locked down there is NO flexure or unwanted movement. I have had that setup (with a 50mm guide scope) since about 2005 and it works great with my 152mm and 80mm APO refractors. I have another 70mm guide scope with a longer focal length  and different focuser that I use with both the 152mm APO refractor and a 11" SCT. The trick is to eliminate ALL possible loose/soft connections....once you do you will get great guiding. 

I don't have the part number of that Huetech focuser anymore so can't help there. 



--
Brian 



Brian Valente


Re: Crayford style focuser for Vario-Finder 10x60 ; 61x250 f/4.1

Robert Berta
 

Huetech used to sell a nice helical focuser that didn't rotate the camera. You can lock down all of the adjustments with thumb screws so once locked down there is NO flexure or unwanted movement. I have had that setup (with a 50mm guide scope) since about 2005 and it works great with my 152mm and 80mm APO refractors. I have another 70mm guide scope with a longer focal length  and different focuser that I use with both the 152mm APO refractor and a 11" SCT. The trick is to eliminate ALL possible loose/soft connections....once you do you will get great guiding. 

I don't have the part number of that Huetech focuser anymore so can't help there. 


Re: "Bump guiding" question - FU question from Roland's experience

Roland Christen
 


can we experiment adding bump guiding using a much smaller attached guidescope?
My inclination is NO, the separate guide scope will be guiding along quite nicely and show no guide errors, but after a few minutes the large scope will slowly point in a different direction than the guide scope, due to differential flexure. That slow motion will be captured on your imaging camera as a slow migration and the stars will eventually be non-round.

How long it takes for the two scopes to point in different directions depends on how much flex the large scope has. It will flex for sure, there is no doubt. If it exceeds 1 arc sec differential, you will probably see out-of round stars. Depends on the seeing of course, but Chile has great seeing and every tiny error will show immediately.

Personally I would never build up a major system like that with a 17" scope and not inherently include an off axis guider. Big Cassegrains are notorious for having flex, especially if the main mirror is heavy and supported by flotation system. It will certainly move sideways as it moves around in the sky. The secondary support will flex for sure. It's a bad system for a separate guide scope.

Rolando


-----Original Message-----
From: Brian Valente <bvalente@...>
To: main@ap-gto.groups.io
Sent: Thu, Oct 15, 2020 3:06 pm
Subject: [ap-gto] "Bump guiding" question - FU question from Roland's experience

For our AP1600AE with a large APCC tracking model installed, can we experiment adding bump guiding using a much smaller attached guidescope? (the 'guide every 10 seconds' approach we were discussing)


the image scale on the main CDK17 is 0.63" 
the image scale on the piggyback scope (SVX80) is approx 1.7"

Right now we can get pretty good results on 600sec exposures, but not sure if the issues we're seeing (minor issues) are seeing or tracking related. 


The reason i'm asking this is because the telescope is in Chile, so buying a compatible OAG, shipping it there, installing it, etc. is quite expensive. We already have the piggyback scope there and available so we can at least try it out if you think it would be a valid test.



--
Brian 



Brian Valente


"Bump guiding" question - FU question from Roland's experience

 

For our AP1600AE with a large APCC tracking model installed, can we experiment adding bump guiding using a much smaller attached guidescope? (the 'guide every 10 seconds' approach we were discussing)


the image scale on the main CDK17 is 0.63" 
the image scale on the piggyback scope (SVX80) is approx 1.7"

Right now we can get pretty good results on 600sec exposures, but not sure if the issues we're seeing (minor issues) are seeing or tracking related. 


The reason i'm asking this is because the telescope is in Chile, so buying a compatible OAG, shipping it there, installing it, etc. is quite expensive. We already have the piggyback scope there and available so we can at least try it out if you think it would be a valid test.



--
Brian 



Brian Valente


Re: Crayford style focuser for Vario-Finder 10x60 ; 61x250 f/4.1

Roland Christen
 

One other thing I recommend is to use Guiding Assistant in PHD. It will help you to choose proper settings.

Rolando


-----Original Message-----
From: uncarollo2 <chris1011@...> via groups.io <chris1011@...>
To: main@ap-gto.groups.io <main@ap-gto.groups.io>
Sent: Thu, Oct 15, 2020 1:21 pm
Subject: Re: [ap-gto] Crayford style focuser for Vario-Finder 10x60 ; 61x250 f/4.1

Look at the P-P values. That will tell you how much the sky is moving around by itself, and you don't want to try to correct for this with your guider. It's impossible really to chase this motion because by the time the guide software has read it, the star has bounded to another value. So the idea is to set the Min Move to be just a bit above this peak value (1/2 of the P-P).

How to calculate the Min Move? At 1x the mount moves 1.5 arc sec per 0.1 seconds of time. So a Min Move value of 0.1sec will ignore all sky motions less than 1.5 arc sec.

Rolando


-----Original Message-----
From: CurtisC via groups.io <calypte@...>
To: main@ap-gto.groups.io
Sent: Thu, Oct 15, 2020 1:01 pm
Subject: Re: [ap-gto] Crayford style focuser for Vario-Finder 10x60 ; 61x250 f/4.1

Thank you. 

Unrelated to the question about the Baader, I tried your suggestion of running a couple of minutes unguided to see how the DEC axis "bobbles."  I wasn't sure what numbers I should evaluate: RMS?  Numbers from the running readout?  Eyeball the lines on the graph?


Re: Crayford style focuser for Vario-Finder 10x60 ; 61x250 f/4.1

Roland Christen
 

Look at the P-P values. That will tell you how much the sky is moving around by itself, and you don't want to try to correct for this with your guider. It's impossible really to chase this motion because by the time the guide software has read it, the star has bounded to another value. So the idea is to set the Min Move to be just a bit above this peak value (1/2 of the P-P).

How to calculate the Min Move? At 1x the mount moves 1.5 arc sec per 0.1 seconds of time. So a Min Move value of 0.1sec will ignore all sky motions less than 1.5 arc sec.

Rolando


-----Original Message-----
From: CurtisC via groups.io <calypte@...>
To: main@ap-gto.groups.io
Sent: Thu, Oct 15, 2020 1:01 pm
Subject: Re: [ap-gto] Crayford style focuser for Vario-Finder 10x60 ; 61x250 f/4.1

Thank you. 

Unrelated to the question about the Baader, I tried your suggestion of running a couple of minutes unguided to see how the DEC axis "bobbles."  I wasn't sure what numbers I should evaluate: RMS?  Numbers from the running readout?  Eyeball the lines on the graph?


Re: Guy on Crowdy Nights needs help

Roland Christen
 

Thank you Brian. Hope it is of some help to this user.

Rolando


-----Original Message-----
From: Brian Valente <bvalente@...>
To: main@ap-gto.groups.io
Sent: Thu, Oct 15, 2020 12:46 pm
Subject: Re: [ap-gto] Guy on Crowdy Nights needs help

am I the last one to hear "Crowdy" Nights? lol

I posted that resonse for you Roland 

On Thu, Oct 15, 2020 at 10:41 AM uncarollo2 <chris1011@...> via groups.io <chris1011=aol.com@groups.io> wrote:
I want to help this user, but I am not on CN, so if anyone on our user group can reach out to him, I have the answer to his problem below.

I am having trouble tracking with my AP Mach1 mount.  I am using Maxim DL, and I have set the "autoguider output control" to "telescope."
I am able to "sort of track" for an hour or so with round stars, but then it becomes impossible once the telescope has pointed much higher in the sky.
 
Calibration.  My  biggest problem is the complete inability to calibrate successfully.   When I try to calibrate, I get an angle between the x and y axes that is far, far from 90 degrees.  It is more like 130 degrees.  So I assume that the lack of calibration is at the heart of my difficulties.
 
I have tried to balance carefully, with the tube balanced first.
lantosque 

Hello,
The problem is quite simple, and you are correct that inability to calibrate will cause guiding problems. Anyone who has used MaximDL for guiding will know that Maxim is notorious for starting the calibration on one star in the field and then switch to another star half way thru the calibration procedure. This produces a bogus calibration. If you are not aware of this and try to use this calibration, then guiding accurately is impossible.

The key is to find a suitable star field that has one dominant bright star so that the program doesn't mix it up with another star in the field. You have to watch carefully during the calibration to make sure that Maxim has not switched stars. I have even seen the program switch from a star to a bright noise pixel.

So, if any of your Astronuts is also on CN, can you please let him know the above, and encourage him to come on this AP group.

Thanks,

Rolando



--
Brian 



Brian Valente


Re: Crayford style focuser for Vario-Finder 10x60 ; 61x250 f/4.1

CurtisC
 

Thank you. 

Unrelated to the question about the Baader, I tried your suggestion of running a couple of minutes unguided to see how the DEC axis "bobbles."  I wasn't sure what numbers I should evaluate: RMS?  Numbers from the running readout?  Eyeball the lines on the graph?


Re: Guy on Crowdy Nights needs help

 

am I the last one to hear "Crowdy" Nights? lol

I posted that resonse for you Roland 

On Thu, Oct 15, 2020 at 10:41 AM uncarollo2 <chris1011@...> via groups.io <chris1011=aol.com@groups.io> wrote:
I want to help this user, but I am not on CN, so if anyone on our user group can reach out to him, I have the answer to his problem below.

I am having trouble tracking with my AP Mach1 mount.  I am using Maxim DL, and I have set the "autoguider output control" to "telescope."
I am able to "sort of track" for an hour or so with round stars, but then it becomes impossible once the telescope has pointed much higher in the sky.
 
Calibration.  My  biggest problem is the complete inability to calibrate successfully.   When I try to calibrate, I get an angle between the x and y axes that is far, far from 90 degrees.  It is more like 130 degrees.  So I assume that the lack of calibration is at the heart of my difficulties.
 
I have tried to balance carefully, with the tube balanced first.
lantosque 

Hello,
The problem is quite simple, and you are correct that inability to calibrate will cause guiding problems. Anyone who has used MaximDL for guiding will know that Maxim is notorious for starting the calibration on one star in the field and then switch to another star half way thru the calibration procedure. This produces a bogus calibration. If you are not aware of this and try to use this calibration, then guiding accurately is impossible.

The key is to find a suitable star field that has one dominant bright star so that the program doesn't mix it up with another star in the field. You have to watch carefully during the calibration to make sure that Maxim has not switched stars. I have even seen the program switch from a star to a bright noise pixel.

So, if any of your Astronuts is also on CN, can you please let him know the above, and encourage him to come on this AP group.

Thanks,

Rolando



--
Brian 



Brian Valente


Guy on Crowdy Nights needs help

Roland Christen
 

I want to help this user, but I am not on CN, so if anyone on our user group can reach out to him, I have the answer to his problem below.

I am having trouble tracking with my AP Mach1 mount.  I am using Maxim DL, and I have set the "autoguider output control" to "telescope."
I am able to "sort of track" for an hour or so with round stars, but then it becomes impossible once the telescope has pointed much higher in the sky.
 
Calibration.  My  biggest problem is the complete inability to calibrate successfully.   When I try to calibrate, I get an angle between the x and y axes that is far, far from 90 degrees.  It is more like 130 degrees.  So I assume that the lack of calibration is at the heart of my difficulties.
 
I have tried to balance carefully, with the tube balanced first.
lantosque 

Hello,
The problem is quite simple, and you are correct that inability to calibrate will cause guiding problems. Anyone who has used MaximDL for guiding will know that Maxim is notorious for starting the calibration on one star in the field and then switch to another star half way thru the calibration procedure. This produces a bogus calibration. If you are not aware of this and try to use this calibration, then guiding accurately is impossible.

The key is to find a suitable star field that has one dominant bright star so that the program doesn't mix it up with another star in the field. You have to watch carefully during the calibration to make sure that Maxim has not switched stars. I have even seen the program switch from a star to a bright noise pixel.

So, if any of your Astronuts is also on CN, can you please let him know the above, and encourage him to come on this AP group.

Thanks,

Rolando


Re: Crayford style focuser for Vario-Finder 10x60 ; 61x250 f/4.1

Roland Christen
 


What is your current feeling about using the Baader Vario-Finder as a guide scope?
The Vario finder works great as a guide scope with most short focus refractors, like the TEC 140.

Rolando


-----Original Message-----
From: CurtisC via groups.io <calypte@...>
To: main@ap-gto.groups.io
Sent: Thu, Oct 15, 2020 6:24 am
Subject: Re: [ap-gto] Crayford style focuser for Vario-Finder 10x60 ; 61x250 f/4.1

Rolando: For a long time I used the Baader Vario-Finder as a guide scope with my TEC140ED (FL = 1035 mm with flattener).  The guider is an SX Superstar.  The Vario-Finder bracket (the one you sell) is mounted to the body of the focuser (Starlight Instruments 3545).  A brief email exchange with Howard a couple of months led me to go back to using the build-in OAG on my QSI 683 ("Why are you using a guide scope?").  As part of my re-evaluation of my guide settings and techniques and other matters, I've pored through hundreds of messages in this forum, going back to the forum's beginning in 2000.  There was some commentary about the Baader guide scope when you introduced it to the A-P product lineup back in 2013, but there hasn't been much since then.  What is your current feeling about using the Baader Vario-Finder as a guide scope?


Re: Unguided imaging and atmospheric refraction

Ray Gralak
 

Hi Allen,

What is the non refracted pole?
Using refraction correction while polar aligning?
Yes. Both PEMPro and APPM (in APCC Pro) will calculate polar alignment to the refracted pole.

-Ray Gralak
Author of PEMPro
Author of APCC (Astro-Physics Command Center): https://www.astro-physics.com/apcc-pro
Author of Astro-Physics V2 ASCOM Driver: https://www.siriusimaging.com/apdriver

-----Original Message-----
From: main@ap-gto.groups.io [mailto:main@ap-gto.groups.io] On Behalf Of Allen Ruckle
Sent: Wednesday, October 14, 2020 8:04 AM
To: main@ap-gto.groups.io
Subject: Re: [ap-gto] Unguided imaging and atmospheric refraction

Ray,
What is the non refracted pole?

Using refraction correction while polar aligning?

aruckle
On Sep 20, 2020, at 12:43 PM, Ray Gralak <groups3@gralak.com> wrote:



Clearly this is a complicated issue with no “perfect” answer.
There will always be a variable tracking rate depending on sky position, so the best solution is polar aligning to the
non-refracted pole.

This works for both unguided and guided setups, as it minimizes field rotation over a long period during which
images are collected.

-Ray Gralak
Author of PEMPro
Author of APCC (Astro-Physics Command Center): https://www.astro-physics.com/apcc-pro
Author of Astro-Physics V2 ASCOM Driver: https://www.siriusimaging.com/apdriver


-----Original Message-----
From: main@ap-gto.groups.io [mailto:main@ap-gto.groups.io] On Behalf Of davidcfinch9 via groups.io
Sent: Sunday, September 20, 2020 12:04 PM
To: main@ap-gto.groups.io
Subject: Re: [ap-gto] Unguided imaging and atmospheric refraction

Clearly this is a complicated issue with no “perfect” answer. The difference in refraction rates with varying
atmospheric conditions adds another level of complexity to this discussion. Without fear of “polishing cannonballs,”
I
don’t think you can go far wrong by polar aligning using your best method and then by spending the time to develop
accurate modeling for your system. You will still be subject to the whims of our atmosphere. The proof will always
be
in your images.

David








Re: Crayford style focuser for Vario-Finder 10x60 ; 61x250 f/4.1

CurtisC
 

Rolando: For a long time I used the Baader Vario-Finder as a guide scope with my TEC140ED (FL = 1035 mm with flattener).  The guider is an SX Superstar.  The Vario-Finder bracket (the one you sell) is mounted to the body of the focuser (Starlight Instruments 3545).  A brief email exchange with Howard a couple of months led me to go back to using the build-in OAG on my QSI 683 ("Why are you using a guide scope?").  As part of my re-evaluation of my guide settings and techniques and other matters, I've pored through hundreds of messages in this forum, going back to the forum's beginning in 2000.  There was some commentary about the Baader guide scope when you introduced it to the A-P product lineup back in 2013, but there hasn't been much since then.  What is your current feeling about using the Baader Vario-Finder as a guide scope?


Re: Crayford style focuser for Vario-Finder 10x60 ; 61x250 f/4.1

Robert Chozick
 

The helical focuser adds no extra length since you move the tube in further to accomodate it.  The tube ends exactly in the same place as before inside of the extension at the end and is much easier to focus.





On Oct 14, 2020, at 5:07 PM, uncarollo2 <chris1011@...> via groups.io <chris1011@...> wrote:

Adding a Crayford focuser will make the system unstable (flex) and defeat the purpose of the finder as a guide scope.

Rolando



-----Original Message-----
From: George <george@...>
To: main@ap-gto.groups.io <main@ap-gto.groups.io>
Sent: Wed, Oct 14, 2020 4:21 pm
Subject: Re: [ap-gto] Crayford style focuser for Vario-Finder 10x60 ; 61x250 f/4.1

Bob,
 
As a reminder, the Baader finder uses the locking ring and lens as a fine focuser.
 
Regards,
 
George
 
George Whitney
Astro-Physics, Inc.
Phone:  815-222-6538 (direct line)
Phone:  815-282-1513 (office)
Email:  george@...
 
From: main@ap-gto.groups.io <main@ap-gto.groups.io> On Behalf Of Woody Schlom
Sent: Wednesday, October 14, 2020 3:02 PM
To: main@ap-gto.groups.io
Subject: Re: [ap-gto] Crayford style focuser for Vario-Finder 10x60 ; 61x250 f/4.1
 
Bob,
 
I don’t know about a Crayford style focuser, but Baader makes nice helical focusers for the Vario-Finder.  The one I have is a 1.25” eyepiece holder with helical focuser built into it.
 
Unfortunately I’m not home now and can’t give you the Baader part number.  But it’s NOT the stock one that comes with the Vario-Finder.  As I recall it’s T2 thread at the scope side – so it just threads on.  And unlike another 1.25” adapter for that scope from Baader, this one has a much longer 1.25” throat – so eyepieces or camera nosepieces don’t wobble nearly as much as Baader’s very short 1.25” adapter.
 
Woody
 
From: main@ap-gto.groups.io [mailto:main@ap-gto.groups.io] On Behalf Of Robert J. Bridges
Sent: Wednesday, October 14, 2020 12:31 PM
To: main@ap-gto.groups.io
Subject: [ap-gto] Crayford style focuser for Vario-Finder 10x60 ; 61x250 f/4.1
 
Hi All,
 
 I would like to replace the sliding focuser on my Vario-Finder (10x60;  61x250 f/4.1) scope with a Crayford style focuser. 
 
Does anyone have a suggestion?
 
Thanks,
Bob
 
--
Robert J. Bridges
Professor
Physiology and Biophysics
Chicago Medical School
3333 Green Bay Rd
North Chicago, Il 60064
Office: 847 578 3273
Cell: 847-271-7944
bob.bridges@...

Robert Chozick




Re: Crayford style focuser for Vario-Finder 10x60 ; 61x250 f/4.1

Roland Christen
 

Adding a Crayford focuser will make the system unstable (flex) and defeat the purpose of the finder as a guide scope.

Rolando



-----Original Message-----
From: George <george@...>
To: main@ap-gto.groups.io <main@ap-gto.groups.io>
Sent: Wed, Oct 14, 2020 4:21 pm
Subject: Re: [ap-gto] Crayford style focuser for Vario-Finder 10x60 ; 61x250 f/4.1

Bob,
 
As a reminder, the Baader finder uses the locking ring and lens as a fine focuser.
 
Regards,
 
George
 
George Whitney
Astro-Physics, Inc.
Phone:  815-222-6538 (direct line)
Phone:  815-282-1513 (office)
Email:  george@...
 
From: main@ap-gto.groups.io <main@ap-gto.groups.io> On Behalf Of Woody Schlom
Sent: Wednesday, October 14, 2020 3:02 PM
To: main@ap-gto.groups.io
Subject: Re: [ap-gto] Crayford style focuser for Vario-Finder 10x60 ; 61x250 f/4.1
 
Bob,
 
I don’t know about a Crayford style focuser, but Baader makes nice helical focusers for the Vario-Finder.  The one I have is a 1.25” eyepiece holder with helical focuser built into it.
 
Unfortunately I’m not home now and can’t give you the Baader part number.  But it’s NOT the stock one that comes with the Vario-Finder.  As I recall it’s T2 thread at the scope side – so it just threads on.  And unlike another 1.25” adapter for that scope from Baader, this one has a much longer 1.25” throat – so eyepieces or camera nosepieces don’t wobble nearly as much as Baader’s very short 1.25” adapter.
 
Woody
 
From: main@ap-gto.groups.io [mailto:main@ap-gto.groups.io] On Behalf Of Robert J. Bridges
Sent: Wednesday, October 14, 2020 12:31 PM
To: main@ap-gto.groups.io
Subject: [ap-gto] Crayford style focuser for Vario-Finder 10x60 ; 61x250 f/4.1
 
Hi All,
 
 I would like to replace the sliding focuser on my Vario-Finder (10x60;  61x250 f/4.1) scope with a Crayford style focuser. 
 
Does anyone have a suggestion?
 
Thanks,
Bob
 
--
Robert J. Bridges
Professor
Physiology and Biophysics
Chicago Medical School
3333 Green Bay Rd
North Chicago, Il 60064
Office: 847 578 3273
Cell: 847-271-7944
bob.bridges@...

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