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Re: [UncensoredTakGroup] Re: TAK 106N Motorized Focus

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  • Neil Fleming
    Sorry, I m not sure.  Each vendor could give you the diameter specs, though...    Cheers...Neil   www.flemingastrophotography.com  Direct from Boston -
    Message 1 of 21 , Mar 24, 2013
      Sorry, I'm not sure.  Each vendor could give you the diameter specs, though...

         Cheers...Neil
       
      www.flemingastrophotography.com 
      Direct from Boston - brilliant diamonds in pea soup
      Also check out the astro_narrowbandYahoo group!



      >________________________________
      > From: galico1952 <galico1952@...>
      >To: UncensoredTakGroup@yahoogroups.com
      >Sent: Sunday, March 24, 2013 7:51 PM
      >Subject: [UncensoredTakGroup] Re: TAK 106N Motorized Focus
      >
      >Neil,
      >Thank you for the fast reply. I didn't think about the method you suggested. Do you know if the focus pinion shaft is the same diameter as a 2.7" TAK Focuser. If that's the case then I should be able to slip the Starlite Insturment Drive gear on the shaft, fit my Motor control to in and be off and running.
      >Steve
      >
      >--- In UncensoredTakGroup@yahoogroups.com, Neil Fleming <neilfleming@...> wrote:
      >>
      >> The advantage to attaching to the coarse focus knob (1:1) is that with focusers like the Micro Touch or Robofocus there will be no slippage for your imaging train.  I have a fairly heavy train on my scope's FT 3545 and had to ditch the fine focus knob in favor of a direct connect to the coarse shaft.  Try your MT system, and if that doesn't work drop me a note and I can direct you to a custom setup for a Robofocus that has extremely fine resolution and more power than the standard edition.
      >>
      >>    Cheers...Neil
      >>  
      >> www.flemingastrophotography.com 
      >> Direct from Boston - brilliant diamonds in pea soup
      >> Also check out the astro_narrowbandYahoo group!
      >>
      >>
      >>
      >> >________________________________
      >> > From: galico1952 <galico1952@...>
      >> >To: UncensoredTakGroup@yahoogroups.com
      >> >Sent: Sunday, March 24, 2013 7:15 PM
      >> >Subject: [UncensoredTakGroup] TAK 106N Motorized Focus
      >> >
      >> >Hi,
      >> >I am looking at a used FSQ 106N. I was told that it comes with the 1:1 Focuser. I need to have a precision, motorized focuser for imaging that is controllable with a PC.
      >> >I have a TAC FS 76 with a Starlite Interment Micro Touch digital system that I just love. Is there anything like this for the 4" ?
      >> >
      >> >Thanks
      >> >Steve
      >> >
      >> >
      >> >
      >> >------------------------------------
      >> >
      >> >Yahoo! Groups Links
      >> >
      >> >
      >> >
      >> >
      >> >
      >> >
      >>
      >> [Non-text portions of this message have been removed]
      >>
      >
      >
      >
      >
      >------------------------------------
      >
      >Yahoo! Groups Links
      >
      >
      >
      >
      >
      >

      [Non-text portions of this message have been removed]
    • Rex
      The FSQ106N has a finer gear ratio on the rack than the FSQ106ED so if you hook a direct drive focuser like a robo focuser on to it you will have a good fine
      Message 2 of 21 , Mar 25, 2013
        The FSQ106N has a finer gear ratio on the rack than the FSQ106ED so if you hook a direct drive focuser like a robo focuser on to it you will have a good fine motion control for focusing.
        Brackets are available for both sides of the FSQ106N, If you mount it to the left side, you can still have a manual focuser on the right side, (if you can find a way to disconnect the robo focus motor from the shaft, I used a custom made releasing clutch to do this).
        As for the shaft size both use a .318" shaft (which is 8mm nominal but slightly larger than 8mm due to the chrome plating on the shaft (8mm = .314") so either micro focuser will fit, the difference is in the flat metal mounting arm that keeps the focuser from turning on the shaft, that is made for each model of focuser.
        Rex

        --- In UncensoredTakGroup@yahoogroups.com, "galico1952" <galico1952@...> wrote:
        >
        > Neil,
        > Thank you for the fast reply. I didn't think about the method you suggested. Do you know if the focus pinion shaft is the same diameter as a 2.7" TAK Focuser. If that's the case then I should be able to slip the Starlite Insturment Drive gear on the shaft, fit my Motor control to in and be off and running.
        > Steve
        >
        > --- In UncensoredTakGroup@yahoogroups.com, Neil Fleming <neilfleming@> wrote:
        > >
        > > The advantage to attaching to the coarse focus knob (1:1) is that with focusers like the Micro Touch or Robofocus there will be no slippage for your imaging train.  I have a fairly heavy train on my scope's FT 3545 and had to ditch the fine focus knob in favor of a direct connect to the coarse shaft.  Try your MT system, and if that doesn't work drop me a note and I can direct you to a custom setup for a Robofocus that has extremely fine resolution and more power than the standard edition.
        > >
        > >    Cheers...Neil
        > >  
        > > www.flemingastrophotography.com 
        > > Direct from Boston - brilliant diamonds in pea soup
        > > Also check out the astro_narrowbandYahoo group!
        > >
        > >
        > >
        > > >________________________________
        > > > From: galico1952 <galico1952@>
        > > >To: UncensoredTakGroup@yahoogroups.com
        > > >Sent: Sunday, March 24, 2013 7:15 PM
        > > >Subject: [UncensoredTakGroup] TAK 106N Motorized Focus
        > > >
        > > >Hi,
        > > >I am looking at a used FSQ 106N. I was told that it comes with the 1:1 Focuser. I need to have a precision, motorized focuser for imaging that is controllable with a PC.
        > > >I have a TAC FS 76 with a Starlite Interment Micro Touch digital system that I just love. Is there anything like this for the 4" ?
        > > >
        > > >Thanks
        > > >Steve
        > > >
        > > >
        > > >
        > > >------------------------------------
        > > >
        > > >Yahoo! Groups Links
        > > >
        > > >
        > > >
        > > >
        > > >
        > > >
        > >
        > > [Non-text portions of this message have been removed]
        > >
        >
      • Rex
        Addendum to my last post: Save yourself a lot of effort and just buy a FLI DF2 or PDF or Atlas focuser ,depending on the weight of your camera, you will get
        Message 3 of 21 , Mar 25, 2013
          Addendum to my last post:
          Save yourself a lot of effort and just buy a FLI DF2 or PDF or Atlas focuser ,depending on the weight of your camera, you will get great results and not need to modify the scope at all.
          Rex

          --- In UncensoredTakGroup@yahoogroups.com, "Rex" <repichr@...> wrote:
          >
          > The FSQ106N has a finer gear ratio on the rack than the FSQ106ED so if you hook a direct drive focuser like a robo focuser on to it you will have a good fine motion control for focusing.
          > Brackets are available for both sides of the FSQ106N, If you mount it to the left side, you can still have a manual focuser on the right side, (if you can find a way to disconnect the robo focus motor from the shaft, I used a custom made releasing clutch to do this).
          > As for the shaft size both use a .318" shaft (which is 8mm nominal but slightly larger than 8mm due to the chrome plating on the shaft (8mm = .314") so either micro focuser will fit, the difference is in the flat metal mounting arm that keeps the focuser from turning on the shaft, that is made for each model of focuser.
          > Rex
          >
          > --- In UncensoredTakGroup@yahoogroups.com, "galico1952" <galico1952@> wrote:
          > >
          > > Neil,
          > > Thank you for the fast reply. I didn't think about the method you suggested. Do you know if the focus pinion shaft is the same diameter as a 2.7" TAK Focuser. If that's the case then I should be able to slip the Starlite Insturment Drive gear on the shaft, fit my Motor control to in and be off and running.
          > > Steve
          > >
          > > --- In UncensoredTakGroup@yahoogroups.com, Neil Fleming <neilfleming@> wrote:
          > > >
          > > > The advantage to attaching to the coarse focus knob (1:1) is that with focusers like the Micro Touch or Robofocus there will be no slippage for your imaging train.  I have a fairly heavy train on my scope's FT 3545 and had to ditch the fine focus knob in favor of a direct connect to the coarse shaft.  Try your MT system, and if that doesn't work drop me a note and I can direct you to a custom setup for a Robofocus that has extremely fine resolution and more power than the standard edition.
          > > >
          > > >    Cheers...Neil
          > > >  
          > > > www.flemingastrophotography.com 
          > > > Direct from Boston - brilliant diamonds in pea soup
          > > > Also check out the astro_narrowbandYahoo group!
          > > >
          > > >
          > > >
          > > > >________________________________
          > > > > From: galico1952 <galico1952@>
          > > > >To: UncensoredTakGroup@yahoogroups.com
          > > > >Sent: Sunday, March 24, 2013 7:15 PM
          > > > >Subject: [UncensoredTakGroup] TAK 106N Motorized Focus
          > > > >
          > > > >Hi,
          > > > >I am looking at a used FSQ 106N. I was told that it comes with the 1:1 Focuser. I need to have a precision, motorized focuser for imaging that is controllable with a PC.
          > > > >I have a TAC FS 76 with a Starlite Interment Micro Touch digital system that I just love. Is there anything like this for the 4" ?
          > > > >
          > > > >Thanks
          > > > >Steve
          > > > >
          > > > >
          > > > >
          > > > >------------------------------------
          > > > >
          > > > >Yahoo! Groups Links
          > > > >
          > > > >
          > > > >
          > > > >
          > > > >
          > > > >
          > > >
          > > > [Non-text portions of this message have been removed]
          > > >
          > >
          >
        • tefwse
          I will chime in here at least for a recommendation. I have had the original FSQ106 for years and always had a Robofocus on it. I added a custom machined
          Message 4 of 21 , Mar 25, 2013
            I will chime in here at least for a recommendation. I have had the original FSQ106 for years and always had a Robofocus on it. I added a custom machined bracket and a stainless helical coupler so it was better than original. It worked, but just OK. The problem with Robofocus is that it has not been really updated in years and has a number of issues. It has always looked like someone's backyard project.

            Last spring I swapped out the focuser for a Starlight 3.5 inch and their motorized focuser boss system. Not cheap, but you get what you pay for and it is a very well engineered piece of kit. It has been nearly bulletproof, I used it all last summer with the STL-8300 with the 8 position filter wheel and the OAG system. I have sold that and will be using it with the equivalent STT system this year. A couple images linked below done with the system.

            http://nightskypictures.com/na_pelly.htm

            http://nightskypictures.com/vdB152.htm

            I like the Starlight so well that I am putting one on my just acquired TOA-130 as well as a third scope that is on order. The focuser boss system can be controlled via either Network or USB/Serial and handles two focusers with one control box. I have sold both my Robofocus systems and never want to see one again.

            As far as the FLI goes, I guess it has a good reputation but I had very poor customer service from FLI on a camera of theirs I used to own so don't deal with them anymore. All of my cameras have been SBIG since and they have been great.
          • Pawel T. Lancucki
            RF motor directly coupled to the FSQ shaft will not have enough precision for critical focusing with for instance FocusMax - too large steps. Personally I have
            Message 5 of 21 , Mar 26, 2013
              RF motor directly coupled to the FSQ shaft will not have enough precision
              for critical focusing with for instance FocusMax - too large steps.
              Personally I have coupled the motor using the microfocuser knob - for 10x
              improveent in resolution. The microfocuser would have to be well adjusted,
              though, to prevent slippage. Replacement with Feathertouch 3,5" focuser is
              a very good but costly solution and requires some surgery on the scope
              (which can be reversed). PDF or Atlas are also very good solutions and do
              not require any engineering, just adapters.

              CS

              Pawel Lancucki


              [Non-text portions of this message have been removed]
            • tefwse
              ... That is just flat wrong. The proof is in the images. It is wrong both by calculation of depth of focus and by personal experience by myself and other
              Message 6 of 21 , Mar 26, 2013
                --- In UncensoredTakGroup@yahoogroups.com, "Pawel T. Lancucki" <pawel.lancucki@...> wrote:

                > RF motor directly coupled to the FSQ shaft will not have enough precision
                > for critical focusing with for instance FocusMax - too large steps.

                That is just flat wrong. The proof is in the images. It is wrong both by calculation of depth of focus and by personal experience by myself and other imagers that I know with extensive experience with the FSQ and Robofocus. For example, tell me that even ONE of the FSQ images from the page below (a friend who uses Robofocus) are out of focus!

                http://www.ccdargo.com/

                I did not save the data but I did calculate the step size using a dial gauge and there were multiple steps within the depth of focus dead band. The problem with Robofocus is the lack of elegance in both hardware and software and the fact that one needs to work harder than one should have to to overcome these limitations. They CAN be overcome but when you buy a product it should just work without re-engineering. Engineering is what you pay the maker for!

                > PDF or Atlas are also very good solutions and do
                > not require any engineering, just adapters.

                From an engineering point of view, tacking stuff on simply increases the chance for sag in the image train. It violates the KISS rule. Might work but then ATLAS is not exactly cheap either so why not replace the whole thing with something akin to the Starlight?
              • Neil Fleming
                Sorry, tefwse, I beg to differ.  I too have an FSQ, and found that when I went to a fine resolution focuser, the measured results improved.  (This was not
                Message 7 of 21 , Mar 26, 2013
                  Sorry, tefwse, I beg to differ.  I too have an FSQ, and found that when I went to a fine resolution focuser, the measured results improved.  (This was not using eyeballs, but actual measurements.  If you want to argue that point, get some empirical measured results...that would indeed be valuable.)

                  1) The current CFZ calculation, as revised by Goldman and Megdal, is:
                  1.6 * F^2 * lambda, where F is the f/ratio (e.g. 5 for an f/5 system), and lambda is the wavelength in microns, e.g. 500 nm = 0.5 microns.  For an F/5 FSQ system, this would work out to 20 microns in the green/blue wavelength.  (The old formula was 2.2 * F/ratio^2, or 55 microns in this example.)

                  Note, however, that this is not always the calculation we're looking for.  Since our telescopes cool over time, especially with our FSQs (with the focuser moving in one direction inward), the more useful calculation is one-half of that, or:
                  0.8 * F^2 * lambda
                   - In our F/5 FSQ example, 10 microns...definitely a lot tighter than we used to think!


                  2)  I'm not 100% sure, but here was the info I found on-line regarding the step size of the RF on the standard RF coarse shaft:
                  "The full travel of the FSQ focuser is ~11,500 steps (at a step size of 1).  The FSQ focus travel is 120mm.  So each step of the RoboFocus is ~.01mm or 10 microns."  Again, I'm not sure of that since it has been some time since I did these measurements myself.

                  3)  So...if 2) is correct, I sure as heck would not want that 1:1 ratio of step size to CFZ!  I'm not saying it won't work...a;ll I am saying is that this ratio does not give me comfort.  Who knows, empirical measurements with this 1:1 ratio might prove me wrong.

                  4)  As nice as the TAK and larger FeatherTouch focusers are visually, they share the same deficient slip-clutch mechanism as many other focusers *when attaching to the fine focus knob*.  The FF knob setup definitely won't hold the weight of today's larger setups.  If you have a heavy setup, then neither the FeatherTouch nor the standard TAK fine-focus knob attachment will work.  That being said, there are some alternative motors and power supplies out there for the Robofocus that have 4 times the step resolution of the standard RF setup, as well as much more power.  I found this necessary to use on my setup out in New Mexico, where I also did a coarse knob attachment, but on a FeatherTouch 3545.  This seems to work very well, and I do recommend it.

                  5)  Given the above, I tend to agree with folks who advise others to get either an FLI Atlas/PDF, or a Clement Bellerophon.  These setups have ultra-fine step sizes.  The custom motor works well, too.

                     Cheers...Neil
                   
                  www.flemingastrophotography.com 
                  Direct from Boston - brilliant diamonds in pea soup
                  Also check out the astro_narrowbandYahoo group!



                  >________________________________
                  > From: tefwse <IC5070@...>
                  >To: UncensoredTakGroup@yahoogroups.com
                  >Sent: Tuesday, March 26, 2013 9:30 AM
                  >Subject: [UncensoredTakGroup] Re: TAK 106N Motorized Focus
                  >
                  >--- In UncensoredTakGroup@yahoogroups.com, "Pawel T. Lancucki" <pawel.lancucki@...> wrote:
                  >
                  >> RF motor directly coupled to the FSQ shaft will not have enough precision
                  >> for critical focusing with for instance FocusMax - too large steps.
                  >
                  >That is just flat wrong. The proof is in the images. It is wrong both by calculation of depth of focus and by personal experience by myself and other imagers that I know with extensive experience with the FSQ and Robofocus. For example, tell me that even ONE of the FSQ images from the page below (a friend who uses Robofocus) are out of focus!
                  >
                  >http://www.ccdargo.com/
                  >
                  >I did not save the data but I did calculate the step size using a dial gauge and there were multiple steps within the depth of focus dead band. The problem with Robofocus is the lack of elegance in both hardware and software and the fact that one needs to work harder than one should have to to overcome these limitations. They CAN be overcome but when you buy a product it should just work without re-engineering. Engineering is what you pay the maker for!
                  >
                  >> PDF or Atlas are also very good solutions and do
                  >> not require any engineering, just adapters.
                  >
                  >From an engineering point of view, tacking stuff on simply increases the chance for sag in the image train. It violates the KISS rule. Might work but then ATLAS is not exactly cheap either so why not replace the whole thing with something akin to the Starlight?
                  >
                  >

                  [Non-text portions of this message have been removed]
                • Mark Acker
                  Neil, do you have a link for the alternatives motors that you mentioned below?  I m thinking about a 106N and would love a look at one.  I have an FT3545 on
                  Message 8 of 21 , Mar 26, 2013
                    Neil, do you have a link for the alternatives motors that you mentioned below?  I'm thinking about a 106N and would love a look at one.  I have an FT3545 on a TOA-130, but no way would I be able to switch a Q and another FT setup.

                    Thank you,
                    Mark



                    ________________________________

                    That being said, there are some alternative motors and power supplies out there for the Robofocus that have 4 times the step resolution of the standard RF setup, as well as much more power. 

                       Cheers...Neil
                     
                    www.flemingastrophotography.com 
                    Direct from Boston - brilliant diamonds in pea soup
                    Also check out the astro_narrowbandYahoo group!

                    >________________________________
                    > From: tefwse <IC5070@...>
                    >To: UncensoredTakGroup@yahoogroups.com
                    >Sent: Tuesday, March 26, 2013 9:30 AM
                    >Subject: [UncensoredTakGroup] Re: TAK 106N Motorized Focus
                    >
                    >--- In UncensoredTakGroup@yahoogroups.com, "Pawel T. Lancucki" <pawel.lancucki@...> wrote:
                    >
                    >> RF motor directly coupled to the FSQ shaft will not have enough precision
                    >> for critical focusing with for instance FocusMax - too large steps.
                    >
                    >That is just flat wrong. The proof is in the images. It is wrong both by calculation of depth of focus and by personal experience by myself and other imagers that I know with extensive experience with the FSQ and Robofocus. For example, tell me that even ONE of the FSQ images from the page below (a friend who uses Robofocus) are out of focus!
                    >
                    >http://www.ccdargo.com/
                    >
                    >I did not save the data but I did calculate the step size using a dial gauge and there were multiple steps within the depth of focus dead band. The problem with Robofocus is the lack of elegance in both hardware and software and the fact that one needs to work harder than one should have to to overcome these limitations. They CAN be overcome but when you buy a product it should just work without re-engineering. Engineering is what you pay the maker for!
                    >
                    >> PDF or Atlas are also very good solutions and do
                    >> not require any engineering, just adapters.
                    >
                    >From an engineering point of view, tacking stuff on simply increases the chance for sag in the image train. It violates the KISS rule. Might work but then ATLAS is not exactly cheap either so why not replace the whole thing with something akin to the Starlight?
                    >
                    >

                    [Non-text portions of this message have been removed]




                    [Non-text portions of this message have been removed]
                  • tefwse
                    Well, I guess that must be why the images at the sites I quoted are such crap. I am sure Tom will be glad to know he has been stupid all these years. I know
                    Message 9 of 21 , Mar 26, 2013
                      Well, I guess that must be why the images at the sites I quoted are such crap. I am sure Tom will be glad to know he has been stupid all these years.

                      I know what works and have been CCD imaging since 1993 with an ST4. Theory is great but if something works, it works. There is more to imaging than theory just as there is more to a product than the specs. A product that has great specs may have poor build quality or (more commonly and more relevant here) lousy customer support. Folks can buy what they want but I wish those who choose to go with Robofocus or FLI lots of luck. You will need it.

                      As for me I am sticking with Starlight focusers, I have one that I have used for a year and have two more on order, one for a TOA-130, the other for a Stellarvue. The customer service is as good as it gets, they even juggled their production schedule for adapters last year to get mine out a bit sooner. Try that with FLI or Tech Innovations!
                    • Neil Fleming
                      Crap?  Good to see you actually *read* my post.  I believe I said,  I m not saying it won t work...a ll I am saying is that this ratio does not give me
                      Message 10 of 21 , Mar 26, 2013
                        "Crap?"  Good to see you actually *read* my post.  I believe I said, " I'm not saying it won't work...a'll I am saying is that this ratio does not give me comfort.  Who knows, empirical measurements with this 1:1 ratio might prove me wrong."  And, "that when I went to a fine resolution focuser, the measured results improved."  Tom does excellent work, I've seen it for years.

                        Instead of a testosterone-based emotional response, go do some empirical work and get some facts.  I believe I was polite and brought out all of the facts and measurements that I had, all to enable a productive conversation.  The tone of your reply is very much unwelcome.  Might be nice if you could use your name, too.

                        As for customer service, I don't believe that was part of the issue.  But now that you mention it, I've worked with Wayne (Starlight) in the past, and have found him indeed superb at customer service.  No complaints whatsoever.  It's just that once you start hanging 22+ lbs off your focuser, and still attempt to use the fine focus knob as an attachment point, you'll run into trouble.

                           Cheers...Neil

                        www.flemingastrophotography.com 
                        Direct from Boston - brilliant diamonds in pea soup
                        Also check out the astro_narrowbandYahoo group!



                        >________________________________
                        > From: tefwse <IC5070@...>
                        >To: UncensoredTakGroup@yahoogroups.com
                        >Sent: Tuesday, March 26, 2013 12:23 PM
                        >Subject: [UncensoredTakGroup] Re: TAK 106N Motorized Focus
                        >
                        >
                        >Well, I guess that must be why the images at the sites I quoted are such crap. I am sure Tom will be glad to know he has been stupid all these years.
                        >
                        >I know what works and have been CCD imaging since 1993 with an ST4. Theory is great but if something works, it works. There is more to imaging than theory just as there is more to a product than the specs. A product that has great specs may have poor build quality or (more commonly and more relevant here) lousy customer support. Folks can buy what they want but I wish those who choose to go with Robofocus or FLI lots of luck. You will need it.
                        >
                        >As for me I am sticking with Starlight focusers, I have one that I have used for a year and have two more on order, one for a TOA-130, the other for a Stellarvue. The customer service is as good as it gets, they even juggled their production schedule for adapters last year to get mine out a bit sooner. Try that with FLI or Tech Innovations!
                        >
                        >
                        >
                        >
                        >________________________________
                        >From: Neil Fleming <neilfleming@...>
                        >To: "UncensoredTakGroup@yahoogroups.com" <UncensoredTakGroup@yahoogroups.com
                        >Sent: Tuesday, March 26, 2013 11:43 AM
                        >Subject: Re: [UncensoredTakGroup] Re: TAK 106N Motorized Focus
                        >
                        >Sorry, tefwse, I beg to differ.  I too have an FSQ, and found that when I went to a fine resolution focuser, the measured results improved.  (This was not using eyeballs, but actual measurements.  If you want to argue that point, get some empirical measured results...that would indeed be valuable.)
                        >
                        >1) The current CFZ calculation, as revised by Goldman and Megdal, is:
                        >1.6 * F^2 * lambda, where F is the f/ratio (e.g. 5 for an f/5 system), and lambda is the wavelength in microns, e.g. 500 nm = 0.5 microns.  For an F/5 FSQ system, this would work out to 20 microns in the green/blue wavelength.  (The old formula was 2.2 * F/ratio^2, or 55 microns in this example.)
                        >
                        >Note, however, that this is not always the calculation we're looking for.  Since our telescopes cool over time, especially with our FSQs (with the focuser moving in one direction inward), the more useful calculation is one-half of that, or:
                        >0.8 * F^2 * lambda
                        > - In our F/5 FSQ example, 10 microns...definitely a lot tighter than we used to think!
                        >
                        >2)  I'm not 100% sure, but here was the info I found on-line regarding the step size of the RF on the standard RF coarse shaft:
                        >"The full travel of the FSQ focuser is ~11,500 steps (at a step size of 1).  The FSQ focus travel is 120mm.  So each step of the RoboFocus is ~.01mm or 10 microns."  Again, I'm not sure of that since it has been some time since I did these measurements myself.
                        >
                        >3)  So...if 2) is correct, I sure as heck would not want that 1:1 ratio of step size to CFZ!  I'm not saying it won't work...a;ll I am saying is that this ratio does not give me comfort.  Who knows, empirical measurements with this 1:1 ratio might prove me wrong.
                        >
                        >4)  As nice as the TAK and larger FeatherTouch focusers are visually, they share the same deficient slip-clutch mechanism as many other focusers *when attaching to the fine focus knob*.  The FF knob setup definitely won't hold the weight of today's larger setups.  If you have a heavy setup, then neither the FeatherTouch nor the standard TAK fine-focus knob attachment will work.  That being said, there are some alternative motors and power supplies out there for the Robofocus that have 4 times the step resolution of the standard RF setup, as well as much more power.  I found this necessary to use on my setup out in New Mexico, where I also did a coarse knob attachment, but on a FeatherTouch 3545.  This seems to work very well, and I do recommend it.
                        >
                        >5)  Given the above, I tend to agree with folks who advise others to get either an FLI Atlas/PDF, or a Clement Bellerophon.  These setups have ultra-fine step sizes.  The custom motor works well, too.
                        >
                        >   Cheers...Neil

                        >www.flemingastrophotography.com 
                        >Direct from Boston - brilliant diamonds in pea soup
                        >Also check out the astro_narrowbandYahoo group!
                        >
                        >

                        [Non-text portions of this message have been removed]
                      • Rex
                        Neil, When I posted my advice on using a Robo-Focus, I was basing it on the old CFZ standard which has been used for many years. I believe that Goldman
                        Message 11 of 21 , Mar 26, 2013
                          Neil,
                          When I posted my advice on using a Robo-Focus, I was basing it on the old CFZ standard which has been used for many years. I believe that Goldman published the revised CFZ standard in Sky & Telescope in 2008 or 2009 and that even today many people except for advanced imagers have not yet heard of it or adopted it as gospel. ( Indeed, I was almost done with imaging with a FSQ106N when the revised CFZ was published).

                          My point being that both side to this issue have a valid point depending on the standard of CFZ you are working with and yes the new standard definitely provides a better quality of image but the old one works for a lot of people also ( most of us are not advanced imagers pushing the boundaries of what is possible from our imaging rigs).

                          That is why I added to my post the advice to go with a FLI focuser as both the Atlas and PDF provide a fine adjustment within the revised CFZ of the FSQ106N and even the DF2 provides twice the resolution of a Robo focus and is therefor an improvement to using it. BUT advanced focusers are not cheap and as always money is the guiding factor in deciding on which equipment to buy. Also, I have quoted only brands that I am familiar with but I know that other good brands are out there ( so please no bashing me for suggesting FLI as I just don't know the resolutions of the other brands and can not speak to them).
                          Rex

                          --- In UncensoredTakGroup@yahoogroups.com, Neil Fleming <neilfleming@...> wrote:
                          >
                          > "Crap?"  Good to see you actually *read* my post.  I believe I said, " I'm not saying it won't work...a'll I am saying is that this ratio does not give me comfort.  Who knows, empirical measurements with this 1:1 ratio might prove me wrong."  And, "that when I went to a fine resolution focuser, the measured results improved."  Tom does excellent work, I've seen it for years.
                          >
                          > Instead of a testosterone-based emotional response, go do some empirical work and get some facts.  I believe I was polite and brought out all of the facts and measurements that I had, all to enable a productive conversation.  The tone of your reply is very much unwelcome.  Might be nice if you could use your name, too.
                          >
                          > As for customer service, I don't believe that was part of the issue.  But now that you mention it, I've worked with Wayne (Starlight) in the past, and have found him indeed superb at customer service.  No complaints whatsoever.  It's just that once you start hanging 22+ lbs off your focuser, and still attempt to use the fine focus knob as an attachment point, you'll run into trouble.
                          >
                          >    Cheers...Neil
                          >
                          > www.flemingastrophotography.com 
                          > Direct from Boston - brilliant diamonds in pea soup
                          > Also check out the astro_narrowbandYahoo group!
                          >
                          >
                          >
                          > >________________________________
                          > > From: tefwse <IC5070@...>
                          > >To: UncensoredTakGroup@yahoogroups.com
                          > >Sent: Tuesday, March 26, 2013 12:23 PM
                          > >Subject: [UncensoredTakGroup] Re: TAK 106N Motorized Focus
                          > >
                          > >
                          > >Well, I guess that must be why the images at the sites I quoted are such crap. I am sure Tom will be glad to know he has been stupid all these years.
                          > >
                          > >I know what works and have been CCD imaging since 1993 with an ST4. Theory is great but if something works, it works. There is more to imaging than theory just as there is more to a product than the specs. A product that has great specs may have poor build quality or (more commonly and more relevant here) lousy customer support. Folks can buy what they want but I wish those who choose to go with Robofocus or FLI lots of luck. You will need it.
                          > >
                          > >As for me I am sticking with Starlight focusers, I have one that I have used for a year and have two more on order, one for a TOA-130, the other for a Stellarvue. The customer service is as good as it gets, they even juggled their production schedule for adapters last year to get mine out a bit sooner. Try that with FLI or Tech Innovations!
                          > >
                          > >
                          > >
                          > >
                          > >________________________________
                          > >From: Neil Fleming <neilfleming@...>
                          > >To: "UncensoredTakGroup@yahoogroups.com" <UncensoredTakGroup@yahoogroups.com
                          > >Sent: Tuesday, March 26, 2013 11:43 AM
                          > >Subject: Re: [UncensoredTakGroup] Re: TAK 106N Motorized Focus
                          > >
                          > >Sorry, tefwse, I beg to differ.  I too have an FSQ, and found that when I went to a fine resolution focuser, the measured results improved.  (This was not using eyeballs, but actual measurements.  If you want to argue that point, get some empirical measured results...that would indeed be valuable.)
                          > >
                          > >1) The current CFZ calculation, as revised by Goldman and Megdal, is:
                          > >1.6 * F^2 * lambda, where F is the f/ratio (e.g. 5 for an f/5 system), and lambda is the wavelength in microns, e.g. 500 nm = 0.5 microns.  For an F/5 FSQ system, this would work out to 20 microns in the green/blue wavelength.  (The old formula was 2.2 * F/ratio^2, or 55 microns in this example.)
                          > >
                          > >Note, however, that this is not always the calculation we're looking for.  Since our telescopes cool over time, especially with our FSQs (with the focuser moving in one direction inward), the more useful calculation is one-half of that, or:
                          > >0.8 * F^2 * lambda
                          > > - In our F/5 FSQ example, 10 microns...definitely a lot tighter than we used to think!
                          > >
                          > >2)  I'm not 100% sure, but here was the info I found on-line regarding the step size of the RF on the standard RF coarse shaft:
                          > >"The full travel of the FSQ focuser is ~11,500 steps (at a step size of 1).  The FSQ focus travel is 120mm.  So each step of the RoboFocus is ~.01mm or 10 microns."  Again, I'm not sure of that since it has been some time since I did these measurements myself.
                          > >
                          > >3)  So...if 2) is correct, I sure as heck would not want that 1:1 ratio of step size to CFZ!  I'm not saying it won't work...a;ll I am saying is that this ratio does not give me comfort.  Who knows, empirical measurements with this 1:1 ratio might prove me wrong.
                          > >
                          > >4)  As nice as the TAK and larger FeatherTouch focusers are visually, they share the same deficient slip-clutch mechanism as many other focusers *when attaching to the fine focus knob*.  The FF knob setup definitely won't hold the weight of today's larger setups.  If you have a heavy setup, then neither the FeatherTouch nor the standard TAK fine-focus knob attachment will work.  That being said, there are some alternative motors and power supplies out there for the Robofocus that have 4 times the step resolution of the standard RF setup, as well as much more power.  I found this necessary to use on my setup out in New Mexico, where I also did a coarse knob attachment, but on a FeatherTouch 3545.  This seems to work very well, and I do recommend it.
                          > >
                          > >5)  Given the above, I tend to agree with folks who advise others to get either an FLI Atlas/PDF, or a Clement Bellerophon.  These setups have ultra-fine step sizes.  The custom motor works well, too.
                          > >
                          > >   Cheers...Neil
                          > > 
                          > >www.flemingastrophotography.com 
                          > >Direct from Boston - brilliant diamonds in pea soup
                          > >Also check out the astro_narrowbandYahoo group!
                          > >
                          > >
                          >
                          > [Non-text portions of this message have been removed]
                          >
                        • domen43i
                          How about some web sites to find out more about these super duper focusers??? Domenic Marra justdomenic@fuse.net ... From: Rex To:
                          Message 12 of 21 , Mar 26, 2013
                            How about some web sites to find out more about these super duper focusers???

                            Domenic Marra
                            justdomenic@...

                            ----- Original Message -----
                            From: Rex <repichr@...>
                            To: UncensoredTakGroup@yahoogroups.com
                            Sent: Tue, 26 Mar 2013 16:19:37 -0400 (EDT)
                            Subject: [UncensoredTakGroup] Re: TAK 106N Motorized Focus





                            Neil,

                            When I posted my advice on using a Robo-Focus, I was basing it on the old CFZ standard which has been used for many years. I believe that Goldman published the revised CFZ standard in Sky & Telescope in 2008 or 2009 and that even today many people except for advanced imagers have not yet heard of it or adopted it as gospel. ( Indeed, I was almost done with imaging with a FSQ106N when the revised CFZ was published).


                            My point being that both side to this issue have a valid point depending on the standard of CFZ you are working with and yes the new standard definitely provides a better quality of image but the old one works for a lot of people also ( most of us are not advanced imagers pushing the boundaries of what is possible from our imaging rigs).


                            That is why I added to my post the advice to go with a FLI focuser as both the Atlas and PDF provide a fine adjustment within the revised CFZ of the FSQ106N and even the DF2 provides twice the resolution of a Robo focus and is therefor an improvement to using it. BUT advanced focusers are not cheap and as always money is the guiding factor in deciding on which equipment to buy. Also, I have quoted only brands that I am familiar with but I know that other good brands are out there ( so please no bashing me for suggesting FLI as I just don't know the resolutions of the other brands and can not speak to them).

                            Rex


                            --- In UncensoredTakGroup@yahoogroups.com, Neil Fleming <neilfleming@...> wrote:

                            >

                            > "Crap?" Good to see you actually *read* my post. I believe I said, " I'm not saying it won't work...a'll I am saying is that this ratio does not give me comfort. Who knows, empirical measurements with this 1:1 ratio might prove me wrong." And, "that when I went to a fine resolution focuser, the measured results improved." Tom does excellent work, I've seen it for years.

                            >

                            > Instead of a testosterone-based emotional response, go do some empirical work and get some facts. I believe I was polite and brought out all of the facts and measurements that I had, all to enable a productive conversation. The tone of your reply is very much unwelcome. Might be nice if you could use your name, too.

                            >

                            > As for customer service, I don't believe that was part of the issue. But now that you mention it, I've worked with Wayne (Starlight) in the past, and have found him indeed superb at customer service. No complaints whatsoever. It's just that once you start hanging 22+ lbs off your focuser, and still attempt to use the fine focus knob as an attachment point, you'll run into trouble.

                            >

                            > Cheers...Neil

                            >

                            > www.flemingastrophotography.com

                            > Direct from Boston - brilliant diamonds in pea soup

                            > Also check out the astro_narrowbandYahoo group!

                            >

                            >

                            >

                            > >________________________________

                            > > From: tefwse <IC5070@...>

                            > >To: UncensoredTakGroup@yahoogroups.com

                            > >Sent: Tuesday, March 26, 2013 12:23 PM

                            > >Subject: [UncensoredTakGroup] Re: TAK 106N Motorized Focus

                            > >

                            > >

                            > >Well, I guess that must be why the images at the sites I quoted are such crap. I am sure Tom will be glad to know he has been stupid all these years.

                            > >

                            > >I know what works and have been CCD imaging since 1993 with an ST4. Theory is great but if something works, it works. There is more to imaging than theory just as there is more to a product than the specs. A product that has great specs may have poor build quality or (more commonly and more relevant here) lousy customer support. Folks can buy what they want but I wish those who choose to go with Robofocus or FLI lots of luck. You will need it.

                            > >

                            > >As for me I am sticking with Starlight focusers, I have one that I have used for a year and have two more on order, one for a TOA-130, the other for a Stellarvue. The customer service is as good as it gets, they even juggled their production schedule for adapters last year to get mine out a bit sooner. Try that with FLI or Tech Innovations!

                            > >

                            > >

                            > >

                            > >

                            > >________________________________

                            > >From: Neil Fleming <neilfleming@...>

                            > >To: "UncensoredTakGroup@yahoogroups.comUncensoredTakGroup@yahoogroups.com>

                            > >Sent: Tuesday, March 26, 2013 11:43 AM

                            > >Subject: Re: [UncensoredTakGroup] Re: TAK 106N Motorized Focus

                            > >

                            > >Sorry, tefwse, I beg to differ. I too have an FSQ, and found that when I went to a fine resolution focuser, the measured results improved. (This was not using eyeballs, but actual measurements. If you want to argue that point, get some empirical measured results...that would indeed be valuable.)

                            > >

                            > >1) The current CFZ calculation, as revised by Goldman and Megdal, is:

                            > >1.6 * F^2 * lambda, where F is the f/ratio (e.g. 5 for an f/5 system), and lambda is the wavelength in microns, e.g. 500 nm = 0.5 microns. For an F/5 FSQ system, this would work out to 20 microns in the green/blue wavelength. (The old formula was 2.2 * F/ratio^2, or 55 microns in this example.)

                            > >

                            > >Note, however, that this is not always the calculation we're looking for. Since our telescopes cool over time, especially with our FSQs (with the focuser moving in one direction inward), the more useful calculation is one-half of that, or:

                            > >0.8 * F^2 * lambda

                            > > - In our F/5 FSQ example, 10 microns...definitely a lot tighter than we used to think!

                            > >

                            > >2) I'm not 100% sure, but here was the info I found on-line regarding the step size of the RF on the standard RF coarse shaft:

                            > >"The full travel of the FSQ focuser is ~11,500 steps (at a step size of 1). The FSQ focus travel is 120mm. So each step of the RoboFocus is ~.01mm or 10 microns." Again, I'm not sure of that since it has been some time since I did these measurements myself.

                            > >

                            > >3) So...if 2) is correct, I sure as heck would not want that 1:1 ratio of step size to CFZ! I'm not saying it won't work...a;ll I am saying is that this ratio does not give me comfort. Who knows, empirical measurements with this 1:1 ratio might prove me wrong.

                            > >

                            > >4) As nice as the TAK and larger FeatherTouch focusers are visually, they share the same deficient slip-clutch mechanism as many other focusers *when attaching to the fine focus knob*. The FF knob setup definitely won't hold the weight of today's larger setups. If you have a heavy setup, then neither the FeatherTouch nor the standard TAK fine-focus knob attachment will work. That being said, there are some alternative motors and power supplies out there for the Robofocus that have 4 times the step resolution of the standard RF setup, as well as much more power. I found this necessary to use on my setup out in New Mexico, where I also did a coarse knob attachment, but on a FeatherTouch 3545. This seems to work very well, and I do recommend it.

                            > >

                            > >5) Given the above, I tend to agree with folks who advise others to get either an FLI Atlas/PDF, or a Clement Bellerophon. These setups have ultra-fine step sizes. The custom motor works well, too.

                            > >

                            > > Cheers...Neil

                            > >

                            > >www.flemingastrophotography.com

                            > >Direct from Boston - brilliant diamonds in pea soup

                            > >Also check out the astro_narrowbandYahoo group!

                            > >

                            > >

                            >

                            > [Non-text portions of this message have been removed]

                            >




                            --
                            Domenic Marra
                            1079 Waycross Rd.
                            Cincinnati, Oh 45240
                            513-825-0099


                            [Non-text portions of this message have been removed]
                          • Rex
                            Good luck finding meaningful info. You can try: http://www.robofocus.com/documents/robofocusins31.pdf http://www.fli-cam.com
                            Message 13 of 21 , Mar 26, 2013
                              Good luck finding meaningful info.
                              You can try:
                              http://www.robofocus.com/documents/robofocusins31.pdf
                              http://www.fli-cam.com
                              http://www.starlightinstruments.com

                              Of the above sites,
                              robofocus provides a good amount of info to determine the step size of your setup.
                              FLI lists the step size of their focusers.
                              I can not find any info on the step size on the Starlight site (maybe in a manual that comes with the focuser system?

                              Also post on imaging sites on this and other Yahoo groups, Cloudy Nights and Astro mart forums with questions for people like Neil that have done the math on the focuser you are interested in.

                              Rex





                              --- In UncensoredTakGroup@yahoogroups.com, justdomenic@... wrote:
                              >
                              > How about some web sites to find out more about these super duper focusers???
                              >
                              > Domenic Marra
                              > justdomenic@...
                              >
                            • Rex
                              Addendum to my post below. I was able to locate the manual for the starlight digital focuser and per its description, the motor at the standard setting moves 1
                              Message 14 of 21 , Mar 26, 2013
                                Addendum to my post below.
                                I was able to locate the manual for the starlight digital focuser and per its description, the motor at the standard setting moves 1 step for 1 count and 300 steps equals 1 revolution of the 10:1 fine focuser or 3000 steps for 1 revolution of the course focuser knob. I measured my 3" FeatherTouch 3035 focuser as moving 0.820" per revolution of the course knob, so:
                                .820"/ 3000 =0.000273" of movement per step, which equals 0.00693 millimeter, which equals to 6.9 micron per step. This is a rough measurement of the focuser movement , to do an accurate one, one would have to command a 3000 step movement and measure, but my measurement is close and this only applies to the 3.0" FT focuser, other models may have a different gear ratio on their racks. YMMV and your measurements differ.
                                Rex

                                --- In UncensoredTakGroup@yahoogroups.com, "Rex" <repichr@...> wrote:
                                >
                                > Good luck finding meaningful info.
                                > You can try:
                                > http://www.robofocus.com/documents/robofocusins31.pdf
                                > http://www.fli-cam.com
                                > http://www.starlightinstruments.com
                                >
                                > Of the above sites,
                                > robofocus provides a good amount of info to determine the step size of your setup.
                                > FLI lists the step size of their focusers.
                                > I can not find any info on the step size on the Starlight site (maybe in a manual that comes with the focuser system?
                                >
                                > Also post on imaging sites on this and other Yahoo groups, Cloudy Nights and Astro mart forums with questions for people like Neil that have done the math on the focuser you are interested in.
                                >
                                > Rex
                                >
                                >
                                >
                                >
                                >
                                > --- In UncensoredTakGroup@yahoogroups.com, justdomenic@ wrote:
                                > >
                                > > How about some web sites to find out more about these super duper focusers???
                                > >
                                > > Domenic Marra
                                > > justdomenic@
                                > >
                                >
                              • dflipp1
                                Neil, you mentioned alternative motors for the Robofocus with higher step resolution. Could you tell us which motors you are referring to? I d be very
                                Message 15 of 21 , Mar 27, 2013
                                  Neil, you mentioned alternative motors for the Robofocus with higher step resolution. Could you tell us which motors you are referring to? I'd be very interested in getting one for my FSQ.

                                  Thanks,
                                  Dan


                                  --- In UncensoredTakGroup@yahoogroups.com, Neil Fleming <neilfleming@...> wrote:
                                  >
                                  > Sorry, tefwse, I beg to differ.  I too have an FSQ, and found that when I went to a fine resolution focuser, the measured results improved.  (This was not using eyeballs, but actual measurements.  If you want to argue that point, get some empirical measured results...that would indeed be valuable.)
                                  >
                                  > 1) The current CFZ calculation, as revised by Goldman and Megdal, is:
                                  > 1.6 * F^2 * lambda, where F is the f/ratio (e.g. 5 for an f/5 system), and lambda is the wavelength in microns, e.g. 500 nm = 0.5 microns.  For an F/5 FSQ system, this would work out to 20 microns in the green/blue wavelength.  (The old formula was 2.2 * F/ratio^2, or 55 microns in this example.)
                                  >
                                  > Note, however, that this is not always the calculation we're looking for.  Since our telescopes cool over time, especially with our FSQs (with the focuser moving in one direction inward), the more useful calculation is one-half of that, or:
                                  > 0.8 * F^2 * lambda
                                  >  - In our F/5 FSQ example, 10 microns...definitely a lot tighter than we used to think!
                                  >
                                  >
                                  > 2)  I'm not 100% sure, but here was the info I found on-line regarding the step size of the RF on the standard RF coarse shaft:
                                  > "The full travel of the FSQ focuser is ~11,500 steps (at a step size of 1).  The FSQ focus travel is 120mm.  So each step of the RoboFocus is ~.01mm or 10 microns."  Again, I'm not sure of that since it has been some time since I did these measurements myself.
                                  >
                                  > 3)  So...if 2) is correct, I sure as heck would not want that 1:1 ratio of step size to CFZ!  I'm not saying it won't work...a;ll I am saying is that this ratio does not give me comfort.  Who knows, empirical measurements with this 1:1 ratio might prove me wrong.
                                  >
                                  > 4)  As nice as the TAK and larger FeatherTouch focusers are visually, they share the same deficient slip-clutch mechanism as many other focusers *when attaching to the fine focus knob*.  The FF knob setup definitely won't hold the weight of today's larger setups.  If you have a heavy setup, then neither the FeatherTouch nor the standard TAK fine-focus knob attachment will work.  That being said, there are some alternative motors and power supplies out there for the Robofocus that have 4 times the step resolution of the standard RF setup, as well as much more power.  I found this necessary to use on my setup out in New Mexico, where I also did a coarse knob attachment, but on a FeatherTouch 3545.  This seems to work very well, and I do recommend it.
                                  >
                                  > 5)  Given the above, I tend to agree with folks who advise others to get either an FLI Atlas/PDF, or a Clement Bellerophon.  These setups have ultra-fine step sizes.  The custom motor works well, too.
                                  >
                                  >    Cheers...Neil
                                  >  
                                  > www.flemingastrophotography.com 
                                  > Direct from Boston - brilliant diamonds in pea soup
                                  > Also check out the astro_narrowbandYahoo group!
                                  >
                                  >
                                  >
                                  > >________________________________
                                  > > From: tefwse <IC5070@...>
                                  > >To: UncensoredTakGroup@yahoogroups.com
                                  > >Sent: Tuesday, March 26, 2013 9:30 AM
                                  > >Subject: [UncensoredTakGroup] Re: TAK 106N Motorized Focus
                                  > >
                                  > >--- In UncensoredTakGroup@yahoogroups.com, "Pawel T. Lancucki" <pawel.lancucki@> wrote:
                                  > >
                                  > >> RF motor directly coupled to the FSQ shaft will not have enough precision
                                  > >> for critical focusing with for instance FocusMax - too large steps.
                                  > >
                                  > >That is just flat wrong. The proof is in the images. It is wrong both by calculation of depth of focus and by personal experience by myself and other imagers that I know with extensive experience with the FSQ and Robofocus. For example, tell me that even ONE of the FSQ images from the page below (a friend who uses Robofocus) are out of focus!
                                  > >
                                  > >http://www.ccdargo.com/
                                  > >
                                  > >I did not save the data but I did calculate the step size using a dial gauge and there were multiple steps within the depth of focus dead band. The problem with Robofocus is the lack of elegance in both hardware and software and the fact that one needs to work harder than one should have to to overcome these limitations. They CAN be overcome but when you buy a product it should just work without re-engineering. Engineering is what you pay the maker for!
                                  > >
                                  > >> PDF or Atlas are also very good solutions and do
                                  > >> not require any engineering, just adapters.
                                  > >
                                  > >From an engineering point of view, tacking stuff on simply increases the chance for sag in the image train. It violates the KISS rule. Might work but then ATLAS is not exactly cheap either so why not replace the whole thing with something akin to the Starlight?
                                  > >
                                  > >
                                  >
                                  > [Non-text portions of this message have been removed]
                                  >
                                • John
                                  To Group and Dan, I have a FSQ 106. I use FLI Atlas focuser and Don Goldman s Monster Moag with Apogee U16M camera. It works fantastic,is error free, and
                                  Message 16 of 21 , Mar 27, 2013
                                    To Group and Dan,
                                    I have a FSQ 106. I use FLI Atlas focuser and Don Goldman's Monster Moag with Apogee U16M camera. It works fantastic,is error free, and consistent, consistent work record. 1800sec pictures are piece of cake with this FLI focuser and Moag.
                                    John Carver

                                    --- In UncensoredTakGroup@yahoogroups.com, "dflipp1" <danny.flippo@...> wrote:
                                    >
                                    > Neil, you mentioned alternative motors for the Robofocus with higher step resolution. Could you tell us which motors you are referring to? I'd be very interested in getting one for my FSQ.
                                    >
                                    > Thanks,
                                    > Dan
                                    >
                                    >
                                    > --- In UncensoredTakGroup@yahoogroups.com, Neil Fleming <neilfleming@> wrote:
                                    > >
                                    > > Sorry, tefwse, I beg to differ.  I too have an FSQ, and found that when I went to a fine resolution focuser, the measured results improved.  (This was not using eyeballs, but actual measurements.  If you want to argue that point, get some empirical measured results...that would indeed be valuable.)
                                    > >
                                    > > 1) The current CFZ calculation, as revised by Goldman and Megdal, is:
                                    > > 1.6 * F^2 * lambda, where F is the f/ratio (e.g. 5 for an f/5 system), and lambda is the wavelength in microns, e.g. 500 nm = 0.5 microns.  For an F/5 FSQ system, this would work out to 20 microns in the green/blue wavelength.  (The old formula was 2.2 * F/ratio^2, or 55 microns in this example.)
                                    > >
                                    > > Note, however, that this is not always the calculation we're looking for.  Since our telescopes cool over time, especially with our FSQs (with the focuser moving in one direction inward), the more useful calculation is one-half of that, or:
                                    > > 0.8 * F^2 * lambda
                                    > >  - In our F/5 FSQ example, 10 microns...definitely a lot tighter than we used to think!
                                    > >
                                    > >
                                    > > 2)  I'm not 100% sure, but here was the info I found on-line regarding the step size of the RF on the standard RF coarse shaft:
                                    > > "The full travel of the FSQ focuser is ~11,500 steps (at a step size of 1).  The FSQ focus travel is 120mm.  So each step of the RoboFocus is ~.01mm or 10 microns."  Again, I'm not sure of that since it has been some time since I did these measurements myself.
                                    > >
                                    > > 3)  So...if 2) is correct, I sure as heck would not want that 1:1 ratio of step size to CFZ!  I'm not saying it won't work...a;ll I am saying is that this ratio does not give me comfort.  Who knows, empirical measurements with this 1:1 ratio might prove me wrong.
                                    > >
                                    > > 4)  As nice as the TAK and larger FeatherTouch focusers are visually, they share the same deficient slip-clutch mechanism as many other focusers *when attaching to the fine focus knob*.  The FF knob setup definitely won't hold the weight of today's larger setups.  If you have a heavy setup, then neither the FeatherTouch nor the standard TAK fine-focus knob attachment will work.  That being said, there are some alternative motors and power supplies out there for the Robofocus that have 4 times the step resolution of the standard RF setup, as well as much more power.  I found this necessary to use on my setup out in New Mexico, where I also did a coarse knob attachment, but on a FeatherTouch 3545.  This seems to work very well, and I do recommend it.
                                    > >
                                    > > 5)  Given the above, I tend to agree with folks who advise others to get either an FLI Atlas/PDF, or a Clement Bellerophon.  These setups have ultra-fine step sizes.  The custom motor works well, too.
                                    > >
                                    > >    Cheers...Neil
                                    > >  
                                    > > www.flemingastrophotography.com 
                                    > > Direct from Boston - brilliant diamonds in pea soup
                                    > > Also check out the astro_narrowbandYahoo group!
                                    > >
                                    > >
                                    > >
                                    > > >________________________________
                                    > > > From: tefwse <IC5070@>
                                    > > >To: UncensoredTakGroup@yahoogroups.com
                                    > > >Sent: Tuesday, March 26, 2013 9:30 AM
                                    > > >Subject: [UncensoredTakGroup] Re: TAK 106N Motorized Focus
                                    > > >
                                    > > >--- In UncensoredTakGroup@yahoogroups.com, "Pawel T. Lancucki" <pawel.lancucki@> wrote:
                                    > > >
                                    > > >> RF motor directly coupled to the FSQ shaft will not have enough precision
                                    > > >> for critical focusing with for instance FocusMax - too large steps.
                                    > > >
                                    > > >That is just flat wrong. The proof is in the images. It is wrong both by calculation of depth of focus and by personal experience by myself and other imagers that I know with extensive experience with the FSQ and Robofocus. For example, tell me that even ONE of the FSQ images from the page below (a friend who uses Robofocus) are out of focus!
                                    > > >
                                    > > >http://www.ccdargo.com/
                                    > > >
                                    > > >I did not save the data but I did calculate the step size using a dial gauge and there were multiple steps within the depth of focus dead band. The problem with Robofocus is the lack of elegance in both hardware and software and the fact that one needs to work harder than one should have to to overcome these limitations. They CAN be overcome but when you buy a product it should just work without re-engineering. Engineering is what you pay the maker for!
                                    > > >
                                    > > >> PDF or Atlas are also very good solutions and do
                                    > > >> not require any engineering, just adapters.
                                    > > >
                                    > > >From an engineering point of view, tacking stuff on simply increases the chance for sag in the image train. It violates the KISS rule. Might work but then ATLAS is not exactly cheap either so why not replace the whole thing with something akin to the Starlight?
                                    > > >
                                    > > >
                                    > >
                                    > > [Non-text portions of this message have been removed]
                                    > >
                                    >
                                  • galico1952
                                    Neil, Dan and All, Thanks for the great replies. I have been hiking for several days and have not had the chance to view the replies. I purchased the FSQ 106N
                                    Message 17 of 21 , Mar 27, 2013
                                      Neil, Dan and All,
                                      Thanks for the great replies. I have been hiking for several days and have not had the chance to view the replies. I purchased the FSQ 106N on Astromart and it will arrive tomorrow. It has the 10:1 focuser.
                                      I Already own the Focus-Boss system that I adapted to my FC 76. I had to buy from Art a 2.7" pinon shaft to make it work and it is so easy and clean. I did not know that a Starlite Inst. 3.5" focuser would work on the 106, I thought it was a 4". Irregardless of the various posts, as usual, I own the FocusBoss so it's a natural to go that direction. I will call tomorrow.
                                      Sounds like I made a great choice with the 106N
                                      Steve

                                      --- In UncensoredTakGroup@yahoogroups.com, "John" <res0hver@...> wrote:
                                      >
                                      >
                                      >
                                      >
                                      >
                                      >
                                      > To Group and Dan,
                                      > I have a FSQ 106. I use FLI Atlas focuser and Don Goldman's Monster Moag with Apogee U16M camera. It works fantastic,is error free, and consistent, consistent work record. 1800sec pictures are piece of cake with this FLI focuser and Moag.
                                      > John Carver
                                      >
                                      > --- In UncensoredTakGroup@yahoogroups.com, "dflipp1" <danny.flippo@> wrote:
                                      > >
                                      > > Neil, you mentioned alternative motors for the Robofocus with higher step resolution. Could you tell us which motors you are referring to? I'd be very interested in getting one for my FSQ.
                                      > >
                                      > > Thanks,
                                      > > Dan
                                      > >
                                      > >
                                      > > --- In UncensoredTakGroup@yahoogroups.com, Neil Fleming <neilfleming@> wrote:
                                      > > >
                                      > > > Sorry, tefwse, I beg to differ.  I too have an FSQ, and found that when I went to a fine resolution focuser, the measured results improved.  (This was not using eyeballs, but actual measurements.  If you want to argue that point, get some empirical measured results...that would indeed be valuable.)
                                      > > >
                                      > > > 1) The current CFZ calculation, as revised by Goldman and Megdal, is:
                                      > > > 1.6 * F^2 * lambda, where F is the f/ratio (e.g. 5 for an f/5 system), and lambda is the wavelength in microns, e.g. 500 nm = 0.5 microns.  For an F/5 FSQ system, this would work out to 20 microns in the green/blue wavelength.  (The old formula was 2.2 * F/ratio^2, or 55 microns in this example.)
                                      > > >
                                      > > > Note, however, that this is not always the calculation we're looking for.  Since our telescopes cool over time, especially with our FSQs (with the focuser moving in one direction inward), the more useful calculation is one-half of that, or:
                                      > > > 0.8 * F^2 * lambda
                                      > > >  - In our F/5 FSQ example, 10 microns...definitely a lot tighter than we used to think!
                                      > > >
                                      > > >
                                      > > > 2)  I'm not 100% sure, but here was the info I found on-line regarding the step size of the RF on the standard RF coarse shaft:
                                      > > > "The full travel of the FSQ focuser is ~11,500 steps (at a step size of 1).  The FSQ focus travel is 120mm.  So each step of the RoboFocus is ~.01mm or 10 microns."  Again, I'm not sure of that since it has been some time since I did these measurements myself.
                                      > > >
                                      > > > 3)  So...if 2) is correct, I sure as heck would not want that 1:1 ratio of step size to CFZ!  I'm not saying it won't work...a;ll I am saying is that this ratio does not give me comfort.  Who knows, empirical measurements with this 1:1 ratio might prove me wrong.
                                      > > >
                                      > > > 4)  As nice as the TAK and larger FeatherTouch focusers are visually, they share the same deficient slip-clutch mechanism as many other focusers *when attaching to the fine focus knob*.  The FF knob setup definitely won't hold the weight of today's larger setups.  If you have a heavy setup, then neither the FeatherTouch nor the standard TAK fine-focus knob attachment will work.  That being said, there are some alternative motors and power supplies out there for the Robofocus that have 4 times the step resolution of the standard RF setup, as well as much more power.  I found this necessary to use on my setup out in New Mexico, where I also did a coarse knob attachment, but on a FeatherTouch 3545.  This seems to work very well, and I do recommend it.
                                      > > >
                                      > > > 5)  Given the above, I tend to agree with folks who advise others to get either an FLI Atlas/PDF, or a Clement Bellerophon.  These setups have ultra-fine step sizes.  The custom motor works well, too.
                                      > > >
                                      > > >    Cheers...Neil
                                      > > >  
                                      > > > www.flemingastrophotography.com 
                                      > > > Direct from Boston - brilliant diamonds in pea soup
                                      > > > Also check out the astro_narrowbandYahoo group!
                                      > > >
                                      > > >
                                      > > >
                                      > > > >________________________________
                                      > > > > From: tefwse <IC5070@>
                                      > > > >To: UncensoredTakGroup@yahoogroups.com
                                      > > > >Sent: Tuesday, March 26, 2013 9:30 AM
                                      > > > >Subject: [UncensoredTakGroup] Re: TAK 106N Motorized Focus
                                      > > > >
                                      > > > >--- In UncensoredTakGroup@yahoogroups.com, "Pawel T. Lancucki" <pawel.lancucki@> wrote:
                                      > > > >
                                      > > > >> RF motor directly coupled to the FSQ shaft will not have enough precision
                                      > > > >> for critical focusing with for instance FocusMax - too large steps.
                                      > > > >
                                      > > > >That is just flat wrong. The proof is in the images. It is wrong both by calculation of depth of focus and by personal experience by myself and other imagers that I know with extensive experience with the FSQ and Robofocus. For example, tell me that even ONE of the FSQ images from the page below (a friend who uses Robofocus) are out of focus!
                                      > > > >
                                      > > > >http://www.ccdargo.com/
                                      > > > >
                                      > > > >I did not save the data but I did calculate the step size using a dial gauge and there were multiple steps within the depth of focus dead band. The problem with Robofocus is the lack of elegance in both hardware and software and the fact that one needs to work harder than one should have to to overcome these limitations. They CAN be overcome but when you buy a product it should just work without re-engineering. Engineering is what you pay the maker for!
                                      > > > >
                                      > > > >> PDF or Atlas are also very good solutions and do
                                      > > > >> not require any engineering, just adapters.
                                      > > > >
                                      > > > >From an engineering point of view, tacking stuff on simply increases the chance for sag in the image train. It violates the KISS rule. Might work but then ATLAS is not exactly cheap either so why not replace the whole thing with something akin to the Starlight?
                                      > > > >
                                      > > > >
                                      > > >
                                      > > > [Non-text portions of this message have been removed]
                                      > > >
                                      > >
                                      >
                                    • terrapassenger
                                      John: I m interested in a similar setup - FSQ 106EDIII, MMOAG, FLI Centerline CFW and FLI PL16803. In your setup, did you remove the FSQ s stock focuser and/or
                                      Message 18 of 21 , Jan 2, 2014

                                        John:


                                        I'm interested in a similar setup - FSQ 106EDIII, MMOAG, FLI Centerline CFW and FLI PL16803.


                                        In your setup, did you remove the FSQ's stock focuser and/or CAA or did you simply lock them in place?  Also, is your FSQ one of the newer models or an older one?  I'm worried about slippage/flexure and see that some imagers with heavy image trains have replaced the stock FSQ components with sleeves and the Atlas focuser.  I'd rather not go to this extreme if necessary but my image train will be quite heavy and I might be forced to do so.

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