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Re: [William Optics] Re: problem with WO FLT 132 + flat68 + STL11000

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  • Perry Holcomb
    It s been said many times before, and it s time to say it again - the WO refractors would be GREAT scopes IF they had an even decent focuser.  Why WO won t
    Message 1 of 15 , Jun 3, 2010
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      It's been said many times before, and it's time to say it again - the WO refractors would be GREAT scopes IF they had an even decent focuser.  Why WO won't bite the bullet and do this has to be a cost matter.

      Well, I offer that WO could sell a hellvua lot more scopes at a higher price if they carried robust focusers!

      That's dumb thinking on their part.  Even the little ZS66SD, which I still have, suffers from a less-than-acceptable focuser.  Only after modding that sucker have I been pleased with the scope as a whole, especially for imaging.

      WO, please take note.

      Better skies,

      Perry

      --- On Thu, 6/3/10, faron123us <faron@...> wrote:

      From: faron123us <faron@...>
      Subject: [William Optics] Re: problem with WO FLT 132 + flat68 + STL11000
      To: William-Optics@yahoogroups.com
      Date: Thursday, June 3, 2010, 12:03 AM

       

      Amadeo, does your flt-132 have a WO crayford focuser? That's the one on mine and there's no way it can handle the weight of your imaging setup. A flexing focuser would probably cause elongated stars. Just something to consider.


    • Dave Y
      Hey Perry what mods did you do??... My FLT110 has a pretty nice focuser- what are the issues you are referring to??. David B. Yates Telescope Performance
      Message 2 of 15 , Jun 3, 2010
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        Hey Perry what mods did you do??...
        My FLT110 has a pretty nice focuser- what are the issues you are referring to??.
         
         
        David B. Yates
        Telescope Performance Improvements (TPI)
        www.tpiastro.com

        Sent: Thursday, June 03, 2010 10:20 AM
        Subject: Re: [William Optics] Re: problem with WO FLT 132 + flat68 + STL11000

         

        It's been said many times before, and it's time to say it again - the WO refractors would be GREAT scopes IF they had an even decent focuser.  Why WO won't bite the bullet and do this has to be a cost matter.

        Well, I offer that WO could sell a hellvua lot more scopes at a higher price if they carried robust focusers!

        That's dumb thinking on their part.  Even the little ZS66SD, which I still have, suffers from a less-than-acceptabl e focuser.  Only after modding that sucker have I been pleased with the scope as a whole, especially for imaging.

        WO, please take note.

        Better skies,

        Perry

        --- On Thu, 6/3/10, faron123us <faron@rogers. com> wrote:

        From: faron123us <faron@rogers. com>
        Subject: [William Optics] Re: problem with WO FLT 132 + flat68 + STL11000
        To: William-Optics@ yahoogroups. com
        Date: Thursday, June 3, 2010, 12:03 AM

         

        Amadeo, does your flt-132 have a WO crayford focuser? That's the one on mine and there's no way it can handle the weight of your imaging setup. A flexing focuser would probably cause elongated stars. Just something to consider.


      • amadeo aznar
        Yes, my telescope has crayfor focuser, so this could be the problem. I think my focusser train weight 3 or 4 kg. There could be the reason of curve field.
        Message 3 of 15 , Jun 3, 2010
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          Yes, my telescope has crayfor focuser, so this could be the problem. I think my focusser train weight 3 or 4 kg. There could be the reason of curve field. Probably.
           
          Regards,


          --- El jue, 3/6/10, Perry Holcomb <hpholcomb@...> escribió:

          De: Perry Holcomb <hpholcomb@...>
          Asunto: Re: [William Optics] Re: problem with WO FLT 132 + flat68 + STL11000
          Para: William-Optics@yahoogroups.com
          Fecha: jueves, 3 de junio, 2010 16:20

           
          It's been said many times before, and it's time to say it again - the WO refractors would be GREAT scopes IF they had an even decent focuser.  Why WO won't bite the bullet and do this has to be a cost matter.

          Well, I offer that WO could sell a hellvua lot more scopes at a higher price if they carried robust focusers!

          That's dumb thinking on their part.  Even the little ZS66SD, which I still have, suffers from a less-than-acceptabl e focuser.  Only after modding that sucker have I been pleased with the scope as a whole, especially for imaging.

          WO, please take note.

          Better skies,

          Perry

          --- On Thu, 6/3/10, faron123us <faron@rogers. com> wrote:

          From: faron123us <faron@rogers. com>
          Subject: [William Optics] Re: problem with WO FLT 132 + flat68 + STL11000
          To: William-Optics@ yahoogroups. com
          Date: Thursday, June 3, 2010, 12:03 AM

           
          Amadeo, does your flt-132 have a WO crayford focuser? That's the one on mine and there's no way it can handle the weight of your imaging setup. A flexing focuser would probably cause elongated stars. Just something to consider.


        • Peter Hughes
          Hi Perry, I have to agree with David. I have the 66 and a ZS80 EDII both with lovely smooth focusers. Granted, they are not Moonlite s, but if you need that
          Message 4 of 15 , Jun 3, 2010
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            Hi Perry,
            I have to agree with David. I have the 66 and a ZS80 EDII both with lovely smooth focusers. Granted, they are not Moonlite's, but if you need that degree of precision, you can always step up with the $$$.
            CS

            Peter C Hughes

            On Jun 3, 2010, at 10:00 AM, "Dave Y" <daveyates80@...> wrote:

             

            Hey Perry what mods did you do??...
            My FLT110 has a pretty nice focuser- what are the issues you are referring to??.
             
             
            David B. Yates
            Telescope Performance Improvements (TPI)
            www.tpiastro. com

            Sent: Thursday, June 03, 2010 10:20 AM
            Subject: Re: [William Optics] Re: problem with WO FLT 132 + flat68 + STL11000

             

            It's been said many times before, and it's time to say it again - the WO refractors would be GREAT scopes IF they had an even decent focuser.  Why WO won't bite the bullet and do this has to be a cost matter.

            Well, I offer that WO could sell a hellvua lot more scopes at a higher price if they carried robust focusers!

            That's dumb thinking on their part.  Even the little ZS66SD, which I still have, suffers from a less-than-acceptabl e focuser.  Only after modding that sucker have I been pleased with the scope as a whole, especially for imaging.

            WO, please take note.

            Better skies,

            Perry

            --- On Thu, 6/3/10, faron123us <faron@rogers. com> wrote:

            From: faron123us <faron@rogers. com>
            Subject: [William Optics] Re: problem with WO FLT 132 + flat68 + STL11000
            To: William-Optics@ yahoogroups. com
            Date: Thursday, June 3, 2010, 12:03 AM

             

            Amadeo, does your flt-132 have a WO crayford focuser? That's the one on mine and there's no way it can handle the weight of your imaging setup. A flexing focuser would probably cause elongated stars. Just something to consider.



          • Perry Holcomb
            Hey Dave, Two primary mods: The one that helped the most was replacing the nylon or teflon tip in the focuser lock screw with a piece cut from a hard rubber
            Message 5 of 15 , Jun 3, 2010
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              Hey Dave,

              Two primary mods:

              The one that helped the most was replacing the nylon or teflon tip in the focuser lock screw with a piece cut from a hard rubber stopper, lab-type, obtainable at Lowe's or HD.

              The other was ensuring all the hardware on the focuser was tight and then properly tightening down the friction-control screw in the middle of the knurled, black knob.  Unless adjusting the friction-control screw, that knob should always be tight!

              Well, the latter aren't truly mods, but they will certainly help hold the draw tube when a cam is on it.

              The piece of rubber stopper works amazingly well in holding the draw tube.  Why WO would put a piece of slippery plastic on the tip of the locking screw is beyond me.

              These "mods" and the slipping draw tube problem have been thoroughly discussed in earlier posts to this group by me and others.

              Good luck, and

              Better skies,

              Perry

              --- On Thu, 6/3/10, Dave Y <daveyates80@...> wrote:

              From: Dave Y <daveyates80@...>
              Subject: Re: [William Optics] Re: problem with WO FLT 132 + flat68 + STL11000
              To: William-Optics@yahoogroups.com
              Date: Thursday, June 3, 2010, 11:00 AM

               

              Hey Perry what mods did you do??...
              My FLT110 has a pretty nice focuser- what are the issues you are referring to??.
               
               
              David B. Yates
              Telescope Performance Improvements (TPI)
              www.tpiastro. com

              Sent: Thursday, June 03, 2010 10:20 AM
              Subject: Re: [William Optics] Re: problem with WO FLT 132 + flat68 + STL11000

               

              It's been said many times before, and it's time to say it again - the WO refractors would be GREAT scopes IF they had an even decent focuser.  Why WO won't bite the bullet and do this has to be a cost matter.

              Well, I offer that WO could sell a hellvua lot more scopes at a higher price if they carried robust focusers!

              That's dumb thinking on their part.  Even the little ZS66SD, which I still have, suffers from a less-than-acceptabl e focuser.  Only after modding that sucker have I been pleased with the scope as a whole, especially for imaging.

              WO, please take note.

              Better skies,

              Perry

              --- On Thu, 6/3/10, faron123us <faron@rogers. com> wrote:

              From: faron123us <faron@rogers. com>
              Subject: [William Optics] Re: problem with WO FLT 132 + flat68 + STL11000
              To: William-Optics@ yahoogroups. com
              Date: Thursday, June 3, 2010, 12:03 AM

               

              Amadeo, does your flt-132 have a WO crayford focuser? That's the one on mine and there's no way it can handle the weight of your imaging setup. A flexing focuser would probably cause elongated stars. Just something to consider.



            • Dave Y
              Hi Perry yes this is what I thought- More making sure the adjustments are correct is the most critical... Cheers, David B. Yates Telescope Performance
              Message 6 of 15 , Jun 3, 2010
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                Hi Perry yes this is what I thought- More making sure the adjustments are correct is the most critical...
                Cheers,
                 
                David B. Yates
                Telescope Performance Improvements (TPI)
                www.tpiastro.com

                Sent: Thursday, June 03, 2010 2:31 PM
                Subject: Re: [William Optics] Re: problem with WO FLT 132 + flat68 + STL11000

                 

                Hey Dave,

                Two primary mods:

                The one that helped the most was replacing the nylon or teflon tip in the focuser lock screw with a piece cut from a hard rubber stopper, lab-type, obtainable at Lowe's or HD.

                The other was ensuring all the hardware on the focuser was tight and then properly tightening down the friction-control screw in the middle of the knurled, black knob.  Unless adjusting the friction-control screw, that knob should always be tight!

                Well, the latter aren't truly mods, but they will certainly help hold the draw tube when a cam is on it.

                The piece of rubber stopper works amazingly well in holding the draw tube.  Why WO would put a piece of slippery plastic on the tip of the locking screw is beyond me.

                These "mods" and the slipping draw tube problem have been thoroughly discussed in earlier posts to this group by me and others.

                Good luck, and

                Better skies,

                Perry

                --- On Thu, 6/3/10, Dave Y <daveyates80@ hotmail.com> wrote:

                From: Dave Y <daveyates80@ hotmail.com>
                Subject: Re: [William Optics] Re: problem with WO FLT 132 + flat68 + STL11000
                To: William-Optics@ yahoogroups. com
                Date: Thursday, June 3, 2010, 11:00 AM

                 

                Hey Perry what mods did you do??...
                My FLT110 has a pretty nice focuser- what are the issues you are referring to??.
                 
                 
                David B. Yates
                Telescope Performance Improvements (TPI)
                www.tpiastro. com

                Sent: Thursday, June 03, 2010 10:20 AM
                Subject: Re: [William Optics] Re: problem with WO FLT 132 + flat68 + STL11000

                 

                It's been said many times before, and it's time to say it again - the WO refractors would be GREAT scopes IF they had an even decent focuser.  Why WO won't bite the bullet and do this has to be a cost matter.

                Well, I offer that WO could sell a hellvua lot more scopes at a higher price if they carried robust focusers!

                That's dumb thinking on their part.  Even the little ZS66SD, which I still have, suffers from a less-than-acceptabl e focuser.  Only after modding that sucker have I been pleased with the scope as a whole, especially for imaging.

                WO, please take note.

                Better skies,

                Perry

                --- On Thu, 6/3/10, faron123us <faron@rogers. com> wrote:

                From: faron123us <faron@rogers. com>
                Subject: [William Optics] Re: problem with WO FLT 132 + flat68 + STL11000
                To: William-Optics@ yahoogroups. com
                Date: Thursday, June 3, 2010, 12:03 AM

                 

                Amadeo, does your flt-132 have a WO crayford focuser? That's the one on mine and there's no way it can handle the weight of your imaging setup. A flexing focuser would probably cause elongated stars. Just something to consider.



              • Timm B
                Hi all - here s what I know - hope this helps clarify some questions that seem to be overlapping and perhaps confusing several different aspects at the same
                Message 7 of 15 , Jun 3, 2010
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                  Hi all - here's what I know - hope this helps clarify some questions that seem to be overlapping and perhaps confusing several different aspects at the same time.

                  All refractors will show field curvature unless it has additional glass to correct it. It shows up in images as uniformly elongated stars that get more and more elongated as you move out of the center of the image (kinda looks like they are racing away from the center). This is due to being a refractor, and doesn't have anything to do with the focuser. There are a couple of ways to remove it for imaging, including a design that incorporates extra elements, like a Petzval design (Televue has a 4 element IS refractor for example) or by adding a field flattener (more glass elements again) that correct for this. The field flattener's ability to correct for these elongated stars (and not introduce other aberrations) depends on the design of the glass, the position and spacing of the glass and the CCD, and how well the flattener's specifications match the scope.

                  IF the elongated stars are not uniform, then what might be happening is focuser sag - this makes the center point where there is no elongation, appear shifted in the image. This is not to be confused with the focuser slipping (which is really an adjustment) where all the stars would be out of focus.

                  Also - I understand what Perry and others are saying about adjusting the focuser and they are absolutely right. To get the best performance from any focuser, it needs to be properly adjusted, and since WO does not offer an option for something like a much more expensive FeatherTouch (nor would most of their market likely pay for that increase on most scope models) the best option is to get used to having to adjust your WO focuser yourself. The 2-speed upgrade, while very nice, does have a limitation in that it was two pieces that are held together which makes it much more prone to needed adjustment than something like the SCT Linear Power focuser, which is actually a rack and pinion, in a more single and unified housing, and not a Crayford design.

                  You can tell by looking at the bottom of the draw tube - if the bottom is smooth and flat, it is a crayford design that uses a steel shaft to put pressure on the aluminum drawtube that gives it smooth friction to focus in and out. If you see teeth, then it is a rack and pinion design.

                  On my 80mm 2" focusuer, I have never found a need to modify the locking screw as Perry suggests for the 66mm scope. I have used mine for imaging only a few times, but I was able to easily hold a Canon 20D Digital SLR without any issues or slippage when locked in place all night a couple of years ago. The white tip made of slippery plastic, works extremely well to lock the drawtube in place but only if the tension is properly adjusted (needs to be reasonably tight). The reason the adjustment is so critical, is that the flat surface on the bottom, is both the place for the friction of the steel shaft, and the friction for the locking screw. This is hard to explain without looking at it, but basically, when you tighten the locking screw, you are also pushing the tube further against the roller bearings on the top of the tube, and also pushing it away from the steel shaft that provides the original friction needed to move the draw tube. So if the friction on the focuser is not initially tight enough, the locking screw alone (with it's tiny slippery plastic tip) will now actually be less friction than what was applied by only the steel shaft against the draw tube shaft. Clear as mud?

                  Perhaps this design simply works better on the 2" focuser I have than the smaller 1.6" focuser, or maybe I just have mine adjusted tighter than others, so it works well for me, I don't know. Really, the big difference when you move to a better focuser like the FeatherTouch (besides costing 2x to 3x) is that it doesn't require as much adjusting over time and temperature changes. Not sure why, but maybe that is why it costs so much more. For the discriminating AP user, this is likely to appeal to them (it's too rich for my blood) so I do wish that WO would offer that segment of users something more expensive directly from the factory.

                  It does seem like WO is listening to us however, which is evident by the introduction of their Linear Power designs, and now their DDG designs. It seems to me that WO is very aware this need, so hopefully the DDG lives up to it's "Product of the Year" fame. I know from using my SCT Linear Power design, it has not needed adjusting at all since I initially installed it and adjusted it to my liking for tension, and I have used it a lot with some very heavy eyepieces without ever seeing any slippage. Again, this is not a crayford design, it uses a very well designed rack and pinion gear assembly.

                  Timm

                  --- In William-Optics@yahoogroups.com, "Dave Y" <daveyates80@...> wrote:
                  >
                  > Hi Perry yes this is what I thought- More making sure the adjustments are correct is the most critical...
                  > Cheers,
                  >
                  > David B. Yates
                  > Telescope Performance Improvements (TPI)
                  > www.tpiastro.com
                  >
                  >
                  >
                  > From: Perry Holcomb
                  > Sent: Thursday, June 03, 2010 2:31 PM
                  > To: William-Optics@yahoogroups.com
                  > Subject: Re: [William Optics] Re: problem with WO FLT 132 + flat68 + STL11000
                  >
                  >
                  >
                  > Hey Dave,
                  >
                  > Two primary mods:
                  >
                  > The one that helped the most was replacing the nylon or teflon tip in the focuser lock screw with a piece cut from a hard rubber stopper, lab-type, obtainable at Lowe's or HD.
                  >
                  > The other was ensuring all the hardware on the focuser was tight and then properly tightening down the friction-control screw in the middle of the knurled, black knob. Unless adjusting the friction-control screw, that knob should always be tight!
                  >
                  > Well, the latter aren't truly mods, but they will certainly help hold the draw tube when a cam is on it.
                  >
                  > The piece of rubber stopper works amazingly well in holding the draw tube. Why WO would put a piece of slippery plastic on the tip of the locking screw is beyond me.
                  >
                  > These "mods" and the slipping draw tube problem have been thoroughly discussed in earlier posts to this group by me and others.
                  >
                  > Good luck, and
                  >
                  > Better skies,
                  >
                  > Perry
                  >
                  > --- On Thu, 6/3/10, Dave Y <daveyates80@...> wrote:
                  >
                  >
                  > From: Dave Y <daveyates80@...>
                  > Subject: Re: [William Optics] Re: problem with WO FLT 132 + flat68 + STL11000
                  > To: William-Optics@yahoogroups.com
                  > Date: Thursday, June 3, 2010, 11:00 AM
                  >
                  >
                  >
                  >
                  > Hey Perry what mods did you do??...
                  > My FLT110 has a pretty nice focuser- what are the issues you are referring to??.
                  >
                  >
                  > David B. Yates
                  > Telescope Performance Improvements (TPI)
                  > www.tpiastro. com
                  >
                  >
                  >
                  > From: Perry Holcomb
                  > Sent: Thursday, June 03, 2010 10:20 AM
                  > To: William-Optics@ yahoogroups. com
                  > Subject: Re: [William Optics] Re: problem with WO FLT 132 + flat68 + STL11000
                  >
                  >
                  >
                  > It's been said many times before, and it's time to say it again - the WO refractors would be GREAT scopes IF they had an even decent focuser. Why WO won't bite the bullet and do this has to be a cost matter.
                  >
                  > Well, I offer that WO could sell a hellvua lot more scopes at a higher price if they carried robust focusers!
                  >
                  > That's dumb thinking on their part. Even the little ZS66SD, which I still have, suffers from a less-than-acceptabl e focuser. Only after modding that sucker have I been pleased with the scope as a whole, especially for imaging.
                  >
                  > WO, please take note.
                  >
                  > Better skies,
                  >
                  > Perry
                  >
                  > --- On Thu, 6/3/10, faron123us <faron@rogers. com> wrote:
                  >
                  >
                  > From: faron123us <faron@rogers. com>
                  > Subject: [William Optics] Re: problem with WO FLT 132 + flat68 + STL11000
                  > To: William-Optics@ yahoogroups. com
                  > Date: Thursday, June 3, 2010, 12:03 AM
                  >
                  >
                  >
                  > Amadeo, does your flt-132 have a WO crayford focuser? That's the one on mine and there's no way it can handle the weight of your imaging setup. A flexing focuser would probably cause elongated stars. Just something to consider.
                  >
                • faron123us
                  I agree that the focusers on the smaller William scopes just need some minor adjustments to work as they should. I ve owned three WO 80mm scopes, a Megrez 90,
                  Message 8 of 15 , Jun 4, 2010
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                    I agree that the focusers on the smaller William scopes just need some minor adjustments to work as they should. I've owned three WO 80mm scopes, a Megrez 90, a Megrez 110, and now the flt-132. None of them sag like my new flt-132. I was told by Tim from WO that this non-rotating crayford is the latest design. I can speak for the focuser on my scope and this one cannot handle the weight of the op's imaging train without flexure. Sure I can tighten it but the focuser doesn't feel right and actually starts to slip. I just wanted to ask Amadeo if he was using the same focuser because it is possible that the sag might be contributing to the problem. Mine sags with a Canon T2i on it. I mentioned in an earlier thread that I knew about the focusers on the flt132 and if I couldn't tweak it to my liking I would upgrade it. I'll be ordering a Moonlite very soon.

                    Faron

                    --- In William-Optics@yahoogroups.com, "amadeoaznar" <amadeoaznar@...> wrote:
                    >
                    > Hi astronomers,
                    >
                    > I have got a flat68 to get a flat field in my pictures. I have install this accesory following the "distance to chip" diagram, but the cuve fiel still apears.
                    >
                    > I have used the adapter that comes with my STL11000. It´s very similar than the DSLR adapter, but maybe bigger than this. But now seen the result in my pictures, i think the distance to chip is not all right.
                    >
                    > Anyone use this configuration to tell me how is the correct distante?
                    >
                    > Thanks for help me.
                    >
                    > Regards,
                    >
                    > Amadeo
                    >
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