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Focuser tension adjustment

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  • newfieninja
    Hey all, Does anyone know where I can find a link to a detailed description on how to adjust the tension on the newer generation refractor crayford focusers?
    Message 1 of 14 , Mar 31, 2009
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      Hey all, Does anyone know where I can find a link to a detailed description on how to adjust the tension on the newer generation refractor crayford focusers?

      I have the aluminum tube flt 98 and was having trouble with the micro adjuster slipping so I started adjusting the tension and now I have tight spots and loose spots when racking the focuser in and out.

      There are 2 set screws on the top of the focuser that seem to adjust the tension on the roller bearings and then there are 2 set screws on the bottom that hold the assembly to the focuser as well as adjust the tension. When I have adjusted the tension I have always had the drawtube racked out and when the tension is adjusted out the movement is very smooth but the focuser will not hold any weight. As I start to bring the tension in, the hard and eazy zones are more pronounced and it even seems as though the focuser shaft slips on the drawtube plate. I probably should never have started to play with the tension but I am new to refractors and the damage is done now. I only hope that there is an easy way out.

      Thanks for the help.

      Lee
    • Sander Pool
      Lee, I don t have an FLT-98 so take this with a grain of salt. The screws on the top of your focuser do not adjust the tension. They keep the bearings in
      Message 2 of 14 , Mar 31, 2009
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        Lee,

        I don't have an FLT-98 so take this with a grain of salt. The screws on
        the top of your focuser do not adjust the tension. They keep the
        bearings in place. They should be tight. The two set screws at the
        bottom can tilt the focus rod. I would think they would normally be
        level. I have not adjusted them as there seems to be no way to know if
        you're doing it right. The central set screw is what puts pressure on
        the whole assembly and that one I cranked down pretty hard. I don't use
        the lock screw at all anymore, in fact it's gone. In my opinion, if
        turning the focus knob doesn't move the load then it's too heavy and the
        lock screw won't help. It'll just de-focus the camera when tightened.
        Opinions will vary on this point I'm sure :)

        Hopefully someone with an FLT-98 can chime in. I assume you've already
        contacted WO for help as well.

        Sander

        newfieninja wrote:
        >
        > Hey all, Does anyone know where I can find a link to a detailed
        > description on how to adjust the tension on the newer generation
        > refractor crayford focusers?
        >
        > I have the aluminum tube flt 98 and was having trouble with the micro
        > adjuster slipping so I started adjusting the tension and now I have
        > tight spots and loose spots when racking the focuser in and out.
        >
        > There are 2 set screws on the top of the focuser that seem to adjust
        > the tension on the roller bearings and then there are 2 set screws on
        > the bottom that hold the assembly to the focuser as well as adjust the
        > tension. When I have adjusted the tension I have always had the
        > drawtube racked out and when the tension is adjusted out the movement
        > is very smooth but the focuser will not hold any weight. As I start to
        > bring the tension in, the hard and eazy zones are more pronounced and
        > it even seems as though the focuser shaft slips on the drawtube plate.
        > I probably should never have started to play with the tension but I am
        > new to refractors and the damage is done now. I only hope that there
        > is an easy way out.
        >
        > Thanks for the help.
        >
        > Lee
        >
        >
      • Charles Brault
        I had a similar problem with a WO 66ED focuser. When I dismantled the focuser, I found almost no lubrication on the three large ball bearings. I also had to
        Message 3 of 14 , Mar 31, 2009
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          I had a similar problem with a WO 66ED focuser. When I dismantled the focuser, I found almost no lubrication on the three large ball bearings. I also had to adjust the pressure on these balls - mine were too tight. It was an iterative process, so be prepared to spend some time with the adjustment. Here is a link to a great tutorial:

          http://www.backyardvoyager.com/gsofocuser.html

          Charlie


          --- In William-Optics@yahoogroups.com, "newfieninja" <newfieninja@...> wrote:
          >
          > Hey all, Does anyone know where I can find a link to a detailed description on how to adjust the tension on the newer generation refractor crayford focusers?
          >
          > I have the aluminum tube flt 98 and was having trouble with the micro adjuster slipping so I started adjusting the tension and now I have tight spots and loose spots when racking the focuser in and out.
          >
          > There are 2 set screws on the top of the focuser that seem to adjust the tension on the roller bearings and then there are 2 set screws on the bottom that hold the assembly to the focuser as well as adjust the tension. When I have adjusted the tension I have always had the drawtube racked out and when the tension is adjusted out the movement is very smooth but the focuser will not hold any weight. As I start to bring the tension in, the hard and eazy zones are more pronounced and it even seems as though the focuser shaft slips on the drawtube plate. I probably should never have started to play with the tension but I am new to refractors and the damage is done now. I only hope that there is an easy way out.
          >
          > Thanks for the help.
          >
          > Lee
          >
        • Sander Pool
          That s an interesting read, thanks for posting! Here are some pictures I took of my M110 focuser: http://gallery.tungstentech.com/main.php?g2_itemId=866 It s
          Message 4 of 14 , Mar 31, 2009
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            That's an interesting read, thanks for posting! Here are some pictures I
            took of my M110 focuser:

            http://gallery.tungstentech.com/main.php?g2_itemId=866

            It's very similar. Now I need to adjust my micro focuser so it'll crank
            'up' as well as down with my camera attached.

            Sander

            Charles Brault wrote:
            >
            > I had a similar problem with a WO 66ED focuser. When I dismantled the
            > focuser, I found almost no lubrication on the three large ball
            > bearings. I also had to adjust the pressure on these balls - mine were
            > too tight. It was an iterative process, so be prepared to spend some
            > time with the adjustment. Here is a link to a great tutorial:
            >
            > http://www.backyardvoyager.com/gsofocuser.html
            > <http://www.backyardvoyager.com/gsofocuser.html>
            >
            > Charlie
            >
            > --- In William-Optics@yahoogroups.com
            > <mailto:William-Optics%40yahoogroups.com>, "newfieninja"
            > <newfieninja@...> wrote:
            > >
            > > Hey all, Does anyone know where I can find a link to a detailed
            > description on how to adjust the tension on the newer generation
            > refractor crayford focusers?
            > >
            > > I have the aluminum tube flt 98 and was having trouble with the
            > micro adjuster slipping so I started adjusting the tension and now I
            > have tight spots and loose spots when racking the focuser in and out.
            > >
            > > There are 2 set screws on the top of the focuser that seem to adjust
            > the tension on the roller bearings and then there are 2 set screws on
            > the bottom that hold the assembly to the focuser as well as adjust the
            > tension. When I have adjusted the tension I have always had the
            > drawtube racked out and when the tension is adjusted out the movement
            > is very smooth but the focuser will not hold any weight. As I start to
            > bring the tension in, the hard and eazy zones are more pronounced and
            > it even seems as though the focuser shaft slips on the drawtube plate.
            > I probably should never have started to play with the tension but I am
            > new to refractors and the damage is done now. I only hope that there
            > is an easy way out.
            > >
            > > Thanks for the help.
            > >
            > > Lee
            > >
            >
            >
          • newfieninja
            Hi Guys, Thanks for the help. I am starting to believe that I have a bearing issue. Using the allen screw hole in the course focuser knob as a marker, the
            Message 5 of 14 , Mar 31, 2009
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              Hi Guys,
              Thanks for the help.

              I am starting to believe that I have a bearing issue. Using the allen screw hole in the course focuser knob as a marker, the roughness is always in the exact spot regardless of where the drawtube is located.

              I have contacted William Optics to see if they can give me any advice on how to diagnose if it is in fact a bearing issue. I have tried micro adjusting the tension but the roughness remains and there is no way to adjust it out, so in my mind it has to be a bearing.

              I also noticed that with little tension on the focuser, if you let it wind out a little quickly you can notice a wobble in the focuser knobs. I was careful not to let the focuser wind all the way out.

              Does anyone know if it is difficult to change a bearing in the focuser assembly?

              Thanks again
              Lee





              --- In William-Optics@yahoogroups.com, Sander Pool <sander@...> wrote:
              >
              >
              > Lee,
              >
              > I don't have an FLT-98 so take this with a grain of salt. The screws on
              > the top of your focuser do not adjust the tension. They keep the
              > bearings in place. They should be tight. The two set screws at the
              > bottom can tilt the focus rod. I would think they would normally be
              > level. I have not adjusted them as there seems to be no way to know if
              > you're doing it right. The central set screw is what puts pressure on
              > the whole assembly and that one I cranked down pretty hard. I don't use
              > the lock screw at all anymore, in fact it's gone. In my opinion, if
              > turning the focus knob doesn't move the load then it's too heavy and the
              > lock screw won't help. It'll just de-focus the camera when tightened.
              > Opinions will vary on this point I'm sure :)
              >
              > Hopefully someone with an FLT-98 can chime in. I assume you've already
              > contacted WO for help as well.
              >
              > Sander
              >
              > newfieninja wrote:
              > >
              > > Hey all, Does anyone know where I can find a link to a detailed
              > > description on how to adjust the tension on the newer generation
              > > refractor crayford focusers?
              > >
              > > I have the aluminum tube flt 98 and was having trouble with the micro
              > > adjuster slipping so I started adjusting the tension and now I have
              > > tight spots and loose spots when racking the focuser in and out.
              > >
              > > There are 2 set screws on the top of the focuser that seem to adjust
              > > the tension on the roller bearings and then there are 2 set screws on
              > > the bottom that hold the assembly to the focuser as well as adjust the
              > > tension. When I have adjusted the tension I have always had the
              > > drawtube racked out and when the tension is adjusted out the movement
              > > is very smooth but the focuser will not hold any weight. As I start to
              > > bring the tension in, the hard and eazy zones are more pronounced and
              > > it even seems as though the focuser shaft slips on the drawtube plate.
              > > I probably should never have started to play with the tension but I am
              > > new to refractors and the damage is done now. I only hope that there
              > > is an easy way out.
              > >
              > > Thanks for the help.
              > >
              > > Lee
              > >
              > >
              >
            • Sander Pool
              Lee, in my M110 it wasn t hard. Check my other message for a link to some photos that show how. WO sent me a new bearing assembly when I reported one had
              Message 6 of 14 , Mar 31, 2009
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                Lee,

                in my M110 it wasn't hard. Check my other message for a link to some
                photos that show how. WO sent me a new bearing assembly when I reported
                one had broken. It was too tight on the brass screw that held it on the
                assembly. The bearings are tiny and not very strong. One screw was too
                big or one bearing too small and as a result the fit was too tight.
                Whoever assembled it simply cranked down with the screw driver and
                forced it on. A second bearing was 'loose' for lack of a better word. I
                could wiggle the bearing with my hand even though the inside was tight
                on the assembly.

                Of course I can not be sure how this is on your scope.

                Sander

                newfieninja wrote:
                >
                > Hi Guys,
                > Thanks for the help.
                >
                > I am starting to believe that I have a bearing issue. Using the allen
                > screw hole in the course focuser knob as a marker, the roughness is
                > always in the exact spot regardless of where the drawtube is located.
                >
                > I have contacted William Optics to see if they can give me any advice
                > on how to diagnose if it is in fact a bearing issue. I have tried
                > micro adjusting the tension but the roughness remains and there is no
                > way to adjust it out, so in my mind it has to be a bearing.
                >
                > I also noticed that with little tension on the focuser, if you let it
                > wind out a little quickly you can notice a wobble in the focuser
                > knobs. I was careful not to let the focuser wind all the way out.
                >
                > Does anyone know if it is difficult to change a bearing in the focuser
                > assembly?
                >
                > Thanks again
                > Lee
                >
                > --- In William-Optics@yahoogroups.com
                > <mailto:William-Optics%40yahoogroups.com>, Sander Pool <sander@...> wrote:
                > >
                > >
                > > Lee,
                > >
                > > I don't have an FLT-98 so take this with a grain of salt. The screws on
                > > the top of your focuser do not adjust the tension. They keep the
                > > bearings in place. They should be tight. The two set screws at the
                > > bottom can tilt the focus rod. I would think they would normally be
                > > level. I have not adjusted them as there seems to be no way to know if
                > > you're doing it right. The central set screw is what puts pressure on
                > > the whole assembly and that one I cranked down pretty hard. I don't use
                > > the lock screw at all anymore, in fact it's gone. In my opinion, if
                > > turning the focus knob doesn't move the load then it's too heavy and
                > the
                > > lock screw won't help. It'll just de-focus the camera when tightened.
                > > Opinions will vary on this point I'm sure :)
                > >
                > > Hopefully someone with an FLT-98 can chime in. I assume you've already
                > > contacted WO for help as well.
                > >
                > > Sander
                > >
                > > newfieninja wrote:
                > > >
                > > > Hey all, Does anyone know where I can find a link to a detailed
                > > > description on how to adjust the tension on the newer generation
                > > > refractor crayford focusers?
                > > >
                > > > I have the aluminum tube flt 98 and was having trouble with the micro
                > > > adjuster slipping so I started adjusting the tension and now I have
                > > > tight spots and loose spots when racking the focuser in and out.
                > > >
                > > > There are 2 set screws on the top of the focuser that seem to adjust
                > > > the tension on the roller bearings and then there are 2 set screws on
                > > > the bottom that hold the assembly to the focuser as well as adjust
                > the
                > > > tension. When I have adjusted the tension I have always had the
                > > > drawtube racked out and when the tension is adjusted out the movement
                > > > is very smooth but the focuser will not hold any weight. As I
                > start to
                > > > bring the tension in, the hard and eazy zones are more pronounced and
                > > > it even seems as though the focuser shaft slips on the drawtube
                > plate.
                > > > I probably should never have started to play with the tension but
                > I am
                > > > new to refractors and the damage is done now. I only hope that there
                > > > is an easy way out.
                > > >
                > > > Thanks for the help.
                > > >
                > > > Lee
                > > >
                > > >
                > >
                >
                >
              • newfieninja
                Hi Sander, I don t think that the bearing problem is in the top part of the focuser IE: the 4 roller bearings, it seems to be in the focuser shaft assembly it
                Message 7 of 14 , Apr 1, 2009
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                  Hi Sander,

                  I don't think that the bearing problem is in the top part of the focuser IE: the 4 roller bearings, it seems to be in the focuser shaft assembly it self. The roughness that I feel is coming directly from the area of the course focuser knob on the right side of the focuser. From what I can tell the only thing that holds the shaft assembly to the focuser is the 2 set screws that also adjust the tension, it would be a simple matter to remove it but I am waiting for word from WO first.

                  Thanks
                  Lee


                  --- In William-Optics@yahoogroups.com, Sander Pool <sander@...> wrote:
                  >
                  >
                  > Lee,
                  >
                  > in my M110 it wasn't hard. Check my other message for a link to some
                  > photos that show how. WO sent me a new bearing assembly when I reported
                  > one had broken. It was too tight on the brass screw that held it on the
                  > assembly. The bearings are tiny and not very strong. One screw was too
                  > big or one bearing too small and as a result the fit was too tight.
                  > Whoever assembled it simply cranked down with the screw driver and
                  > forced it on. A second bearing was 'loose' for lack of a better word. I
                  > could wiggle the bearing with my hand even though the inside was tight
                  > on the assembly.
                  >
                  > Of course I can not be sure how this is on your scope.
                  >
                  > Sander
                  >
                  > newfieninja wrote:
                  > >
                  > > Hi Guys,
                  > > Thanks for the help.
                  > >
                  > > I am starting to believe that I have a bearing issue. Using the allen
                  > > screw hole in the course focuser knob as a marker, the roughness is
                  > > always in the exact spot regardless of where the drawtube is located.
                  > >
                  > > I have contacted William Optics to see if they can give me any advice
                  > > on how to diagnose if it is in fact a bearing issue. I have tried
                  > > micro adjusting the tension but the roughness remains and there is no
                  > > way to adjust it out, so in my mind it has to be a bearing.
                  > >
                  > > I also noticed that with little tension on the focuser, if you let it
                  > > wind out a little quickly you can notice a wobble in the focuser
                  > > knobs. I was careful not to let the focuser wind all the way out.
                  > >
                  > > Does anyone know if it is difficult to change a bearing in the focuser
                  > > assembly?
                  > >
                  > > Thanks again
                  > > Lee
                  > >
                  > > --- In William-Optics@yahoogroups.com
                  > > <mailto:William-Optics%40yahoogroups.com>, Sander Pool <sander@> wrote:
                  > > >
                  > > >
                  > > > Lee,
                  > > >
                  > > > I don't have an FLT-98 so take this with a grain of salt. The screws on
                  > > > the top of your focuser do not adjust the tension. They keep the
                  > > > bearings in place. They should be tight. The two set screws at the
                  > > > bottom can tilt the focus rod. I would think they would normally be
                  > > > level. I have not adjusted them as there seems to be no way to know if
                  > > > you're doing it right. The central set screw is what puts pressure on
                  > > > the whole assembly and that one I cranked down pretty hard. I don't use
                  > > > the lock screw at all anymore, in fact it's gone. In my opinion, if
                  > > > turning the focus knob doesn't move the load then it's too heavy and
                  > > the
                  > > > lock screw won't help. It'll just de-focus the camera when tightened.
                  > > > Opinions will vary on this point I'm sure :)
                  > > >
                  > > > Hopefully someone with an FLT-98 can chime in. I assume you've already
                  > > > contacted WO for help as well.
                  > > >
                  > > > Sander
                  > > >
                  > > > newfieninja wrote:
                  > > > >
                  > > > > Hey all, Does anyone know where I can find a link to a detailed
                  > > > > description on how to adjust the tension on the newer generation
                  > > > > refractor crayford focusers?
                  > > > >
                  > > > > I have the aluminum tube flt 98 and was having trouble with the micro
                  > > > > adjuster slipping so I started adjusting the tension and now I have
                  > > > > tight spots and loose spots when racking the focuser in and out.
                  > > > >
                  > > > > There are 2 set screws on the top of the focuser that seem to adjust
                  > > > > the tension on the roller bearings and then there are 2 set screws on
                  > > > > the bottom that hold the assembly to the focuser as well as adjust
                  > > the
                  > > > > tension. When I have adjusted the tension I have always had the
                  > > > > drawtube racked out and when the tension is adjusted out the movement
                  > > > > is very smooth but the focuser will not hold any weight. As I
                  > > start to
                  > > > > bring the tension in, the hard and eazy zones are more pronounced and
                  > > > > it even seems as though the focuser shaft slips on the drawtube
                  > > plate.
                  > > > > I probably should never have started to play with the tension but
                  > > I am
                  > > > > new to refractors and the damage is done now. I only hope that there
                  > > > > is an easy way out.
                  > > > >
                  > > > > Thanks for the help.
                  > > > >
                  > > > > Lee
                  > > > >
                  > > > >
                  > > >
                  > >
                  > >
                  >
                • Sander Pool
                  Hi Lee, I look forward to your report after WO gets back to you. It s the right call to not remove anything till WO advises you to do do. I ve also felt some
                  Message 8 of 14 , Apr 1, 2009
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                    Hi Lee,

                    I look forward to your report after WO gets back to you. It's the right
                    call to not remove anything till WO advises you to do do.

                    I've also felt some of this roughness in the focuser but could never
                    determine if it was the focuser itself or the crayford shaft rolling on
                    the not perfectly smooth drawtube.

                    Sander

                    newfieninja wrote:
                    >
                    > Hi Sander,
                    >
                    > I don't think that the bearing problem is in the top part of the
                    > focuser IE: the 4 roller bearings, it seems to be in the focuser shaft
                    > assembly it self. The roughness that I feel is coming directly from
                    > the area of the course focuser knob on the right side of the focuser.
                    > From what I can tell the only thing that holds the shaft assembly to
                    > the focuser is the 2 set screws that also adjust the tension, it would
                    > be a simple matter to remove it but I am waiting for word from WO first.
                    >
                    > Thanks
                    > Lee
                    >
                    >
                    >
                  • newfieninja
                    Hi Sander, If WO gives me the go ahead to remove the focuser shaft assembly from the focuser, I will take some pics and post them in the photos section. Lee
                    Message 9 of 14 , Apr 1, 2009
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                      Hi Sander,

                      If WO gives me the go ahead to remove the focuser shaft assembly from the focuser, I will take some pics and post them in the photos section.

                      Lee






                      --- In William-Optics@yahoogroups.com, Sander Pool <sander@...> wrote:
                      >
                      >
                      > Hi Lee,
                      >
                      > I look forward to your report after WO gets back to you. It's the right
                      > call to not remove anything till WO advises you to do do.
                      >
                      > I've also felt some of this roughness in the focuser but could never
                      > determine if it was the focuser itself or the crayford shaft rolling on
                      > the not perfectly smooth drawtube.
                      >
                      > Sander
                      >
                      > newfieninja wrote:
                      > >
                      > > Hi Sander,
                      > >
                      > > I don't think that the bearing problem is in the top part of the
                      > > focuser IE: the 4 roller bearings, it seems to be in the focuser shaft
                      > > assembly it self. The roughness that I feel is coming directly from
                      > > the area of the course focuser knob on the right side of the focuser.
                      > > From what I can tell the only thing that holds the shaft assembly to
                      > > the focuser is the 2 set screws that also adjust the tension, it would
                      > > be a simple matter to remove it but I am waiting for word from WO first.
                      > >
                      > > Thanks
                      > > Lee
                      > >
                      > >
                      > >
                      >
                    • newfieninja
                      Hello Sander, I have been speaking to Tim at WO, he is being very helpful. He is going to send me pictures of how to remove the shaft assembly and if that is
                      Message 10 of 14 , Apr 2, 2009
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                        Hello Sander,

                        I have been speaking to Tim at WO, he is being very helpful. He is going to send me pictures of how to remove the shaft assembly and if that is not the problem, I will return the focuser to WO to be repaired or replaced. Great service from WO as usual. I will keep you updated.

                        Cheers
                        Lee

                        --- In William-Optics@yahoogroups.com, "newfieninja" <newfieninja@...> wrote:
                        >
                        > Hi Sander,
                        >
                        > If WO gives me the go ahead to remove the focuser shaft assembly from the focuser, I will take some pics and post them in the photos section.
                        >
                        > Lee
                        >
                        >
                        >
                        >
                        >
                        >
                        > --- In William-Optics@yahoogroups.com, Sander Pool <sander@> wrote:
                        > >
                        > >
                        > > Hi Lee,
                        > >
                        > > I look forward to your report after WO gets back to you. It's the right
                        > > call to not remove anything till WO advises you to do do.
                        > >
                        > > I've also felt some of this roughness in the focuser but could never
                        > > determine if it was the focuser itself or the crayford shaft rolling on
                        > > the not perfectly smooth drawtube.
                        > >
                        > > Sander
                        > >
                        > > newfieninja wrote:
                        > > >
                        > > > Hi Sander,
                        > > >
                        > > > I don't think that the bearing problem is in the top part of the
                        > > > focuser IE: the 4 roller bearings, it seems to be in the focuser shaft
                        > > > assembly it self. The roughness that I feel is coming directly from
                        > > > the area of the course focuser knob on the right side of the focuser.
                        > > > From what I can tell the only thing that holds the shaft assembly to
                        > > > the focuser is the 2 set screws that also adjust the tension, it would
                        > > > be a simple matter to remove it but I am waiting for word from WO first.
                        > > >
                        > > > Thanks
                        > > > Lee
                        > > >
                        > > >
                        > > >
                        > >
                        >
                      • Charles Brault
                        There probably is nothing wrong with your bearings. There are two sets of bearings in the mechanism - the three large ones which are open and visible, and a
                        Message 11 of 14 , Apr 2, 2009
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                          There probably is nothing wrong with your bearings. There are two sets of bearings in the mechanism - the three large ones which are open and visible, and a set of very small (maybe 20 or so) bearings on the opposite side of the large bearings. There is a an adjuster that varies the tension on the bronze race for these small bearings. If you go to my photos (CharlieB) I have two views that show what to adjust. There is some type of Loctite on the threads, so it may take some doing to change this tension (if you completely disassemble this adjuster to lubricate, you'll have to reapply a small amount of BLUE Loctite). Both sets of bearings on my focuser were virtually dry and very rough in turning. After I lubed and adjusted the race, everything was great. A WORD OF CAUTION!! If you take the race completely off to lubricate, be ready to catch all the little bearings that WILL come out. I spent 1/2 hour with a magnet scouring the floor because I was careless. You'll have to test any adjustments by putting it all back together again. However, if you get that wobble in the foucuser when you spin the large knob back and forth, your need more tension on the bearing race, so this will be a guide. This also cured the drawtube slipping down all the time. One more hint - leave a tiny gap between the large and small focus knobs so there is absolutely no rubbing. That helps a great deal to smooth out the focuser.

                          Charlie

                          --- In William-Optics@yahoogroups.com, "newfieninja" <newfieninja@...> wrote:
                          >
                          > Hi Guys,
                          > Thanks for the help.
                          >
                          > I am starting to believe that I have a bearing issue. Using the allen screw hole in the course focuser knob as a marker, the roughness is always in the exact spot regardless of where the drawtube is located.
                          >
                          > I have contacted William Optics to see if they can give me any advice on how to diagnose if it is in fact a bearing issue. I have tried micro adjusting the tension but the roughness remains and there is no way to adjust it out, so in my mind it has to be a bearing.
                          >
                          > I also noticed that with little tension on the focuser, if you let it wind out a little quickly you can notice a wobble in the focuser knobs. I was careful not to let the focuser wind all the way out.
                          >
                          > Does anyone know if it is difficult to change a bearing in the focuser assembly?
                          >
                          > Thanks again
                          > Lee
                          >
                          >
                          >
                          >
                          >
                          > --- In William-Optics@yahoogroups.com, Sander Pool <sander@> wrote:
                          > >
                          > >
                          > > Lee,
                          > >
                          > > I don't have an FLT-98 so take this with a grain of salt. The screws on
                          > > the top of your focuser do not adjust the tension. They keep the
                          > > bearings in place. They should be tight. The two set screws at the
                          > > bottom can tilt the focus rod. I would think they would normally be
                          > > level. I have not adjusted them as there seems to be no way to know if
                          > > you're doing it right. The central set screw is what puts pressure on
                          > > the whole assembly and that one I cranked down pretty hard. I don't use
                          > > the lock screw at all anymore, in fact it's gone. In my opinion, if
                          > > turning the focus knob doesn't move the load then it's too heavy and the
                          > > lock screw won't help. It'll just de-focus the camera when tightened.
                          > > Opinions will vary on this point I'm sure :)
                          > >
                          > > Hopefully someone with an FLT-98 can chime in. I assume you've already
                          > > contacted WO for help as well.
                          > >
                          > > Sander
                          > >
                          > > newfieninja wrote:
                          > > >
                          > > > Hey all, Does anyone know where I can find a link to a detailed
                          > > > description on how to adjust the tension on the newer generation
                          > > > refractor crayford focusers?
                          > > >
                          > > > I have the aluminum tube flt 98 and was having trouble with the micro
                          > > > adjuster slipping so I started adjusting the tension and now I have
                          > > > tight spots and loose spots when racking the focuser in and out.
                          > > >
                          > > > There are 2 set screws on the top of the focuser that seem to adjust
                          > > > the tension on the roller bearings and then there are 2 set screws on
                          > > > the bottom that hold the assembly to the focuser as well as adjust the
                          > > > tension. When I have adjusted the tension I have always had the
                          > > > drawtube racked out and when the tension is adjusted out the movement
                          > > > is very smooth but the focuser will not hold any weight. As I start to
                          > > > bring the tension in, the hard and eazy zones are more pronounced and
                          > > > it even seems as though the focuser shaft slips on the drawtube plate.
                          > > > I probably should never have started to play with the tension but I am
                          > > > new to refractors and the damage is done now. I only hope that there
                          > > > is an easy way out.
                          > > >
                          > > > Thanks for the help.
                          > > >
                          > > > Lee
                          > > >
                          > > >
                          > >
                          >
                        • newfieninja
                          Hi Charlie, Thanks for the info. When you took the shaft assembly off and turned the focus knob was there any stiction or wobble with it spinning freely? I
                          Message 12 of 14 , Apr 2, 2009
                          • 0 Attachment
                            Hi Charlie,

                            Thanks for the info. When you took the shaft assembly off and turned the focus knob was there any stiction or wobble with it spinning freely? I took a look at your pics and will compare them to the pictures that Tim sends me from WO. I will post again after I get them.

                            Cheers
                            Lee

                            --- In William-Optics@yahoogroups.com, "Charles Brault" <braultc52@...> wrote:
                            >
                            > There probably is nothing wrong with your bearings. There are two sets of bearings in the mechanism - the three large ones which are open and visible, and a set of very small (maybe 20 or so) bearings on the opposite side of the large bearings. There is a an adjuster that varies the tension on the bronze race for these small bearings. If you go to my photos (CharlieB) I have two views that show what to adjust. There is some type of Loctite on the threads, so it may take some doing to change this tension (if you completely disassemble this adjuster to lubricate, you'll have to reapply a small amount of BLUE Loctite). Both sets of bearings on my focuser were virtually dry and very rough in turning. After I lubed and adjusted the race, everything was great. A WORD OF CAUTION!! If you take the race completely off to lubricate, be ready to catch all the little bearings that WILL come out. I spent 1/2 hour with a magnet scouring the floor because I was careless. You'll have to test any adjustments by putting it all back together again. However, if you get that wobble in the foucuser when you spin the large knob back and forth, your need more tension on the bearing race, so this will be a guide. This also cured the drawtube slipping down all the time. One more hint - leave a tiny gap between the large and small focus knobs so there is absolutely no rubbing. That helps a great deal to smooth out the focuser.
                            >
                            > Charlie
                            >
                            > --- In William-Optics@yahoogroups.com, "newfieninja" <newfieninja@> wrote:
                            > >
                            > > Hi Guys,
                            > > Thanks for the help.
                            > >
                            > > I am starting to believe that I have a bearing issue. Using the allen screw hole in the course focuser knob as a marker, the roughness is always in the exact spot regardless of where the drawtube is located.
                            > >
                            > > I have contacted William Optics to see if they can give me any advice on how to diagnose if it is in fact a bearing issue. I have tried micro adjusting the tension but the roughness remains and there is no way to adjust it out, so in my mind it has to be a bearing.
                            > >
                            > > I also noticed that with little tension on the focuser, if you let it wind out a little quickly you can notice a wobble in the focuser knobs. I was careful not to let the focuser wind all the way out.
                            > >
                            > > Does anyone know if it is difficult to change a bearing in the focuser assembly?
                            > >
                            > > Thanks again
                            > > Lee
                            > >
                            > >
                            > >
                            > >
                            > >
                            > > --- In William-Optics@yahoogroups.com, Sander Pool <sander@> wrote:
                            > > >
                            > > >
                            > > > Lee,
                            > > >
                            > > > I don't have an FLT-98 so take this with a grain of salt. The screws on
                            > > > the top of your focuser do not adjust the tension. They keep the
                            > > > bearings in place. They should be tight. The two set screws at the
                            > > > bottom can tilt the focus rod. I would think they would normally be
                            > > > level. I have not adjusted them as there seems to be no way to know if
                            > > > you're doing it right. The central set screw is what puts pressure on
                            > > > the whole assembly and that one I cranked down pretty hard. I don't use
                            > > > the lock screw at all anymore, in fact it's gone. In my opinion, if
                            > > > turning the focus knob doesn't move the load then it's too heavy and the
                            > > > lock screw won't help. It'll just de-focus the camera when tightened.
                            > > > Opinions will vary on this point I'm sure :)
                            > > >
                            > > > Hopefully someone with an FLT-98 can chime in. I assume you've already
                            > > > contacted WO for help as well.
                            > > >
                            > > > Sander
                            > > >
                            > > > newfieninja wrote:
                            > > > >
                            > > > > Hey all, Does anyone know where I can find a link to a detailed
                            > > > > description on how to adjust the tension on the newer generation
                            > > > > refractor crayford focusers?
                            > > > >
                            > > > > I have the aluminum tube flt 98 and was having trouble with the micro
                            > > > > adjuster slipping so I started adjusting the tension and now I have
                            > > > > tight spots and loose spots when racking the focuser in and out.
                            > > > >
                            > > > > There are 2 set screws on the top of the focuser that seem to adjust
                            > > > > the tension on the roller bearings and then there are 2 set screws on
                            > > > > the bottom that hold the assembly to the focuser as well as adjust the
                            > > > > tension. When I have adjusted the tension I have always had the
                            > > > > drawtube racked out and when the tension is adjusted out the movement
                            > > > > is very smooth but the focuser will not hold any weight. As I start to
                            > > > > bring the tension in, the hard and eazy zones are more pronounced and
                            > > > > it even seems as though the focuser shaft slips on the drawtube plate.
                            > > > > I probably should never have started to play with the tension but I am
                            > > > > new to refractors and the damage is done now. I only hope that there
                            > > > > is an easy way out.
                            > > > >
                            > > > > Thanks for the help.
                            > > > >
                            > > > > Lee
                            > > > >
                            > > > >
                            > > >
                            > >
                            >
                          • Charles Brault
                            When I took the assembly off the scope and turned the small and laege knobs, there was plenty of stiction. The Bearings were dry (as I noted before) and the
                            Message 13 of 14 , Apr 3, 2009
                            • 0 Attachment
                              When I took the assembly off the scope and turned the small and laege knobs, there was plenty of stiction. The Bearings were dry (as I noted before) and the pressure plate was way too tight. When I lubed it and loosened it, it started spinning very freely. Once I had everything right and reassembled it, the external tension set screw (the one with the knurled locking nut) really allowed me to set the tension so the focusing tube stayed put even under quite a load and it still was operating smoothly.

                              Charlie
                              --- In William-Optics@yahoogroups.com, "newfieninja" <newfieninja@...> wrote:
                              >
                              > Hi Charlie,
                              >
                              > Thanks for the info. When you took the shaft assembly off and turned the focus knob was there any stiction or wobble with it spinning freely? I took a look at your pics and will compare them to the pictures that Tim sends me from WO. I will post again after I get them.
                              >
                              > Cheers
                              > Lee
                              >
                              > --- In William-Optics@yahoogroups.com, "Charles Brault" <braultc52@> wrote:
                              > >
                              > > There probably is nothing wrong with your bearings. There are two sets of bearings in the mechanism - the three large ones which are open and visible, and a set of very small (maybe 20 or so) bearings on the opposite side of the large bearings. There is a an adjuster that varies the tension on the bronze race for these small bearings. If you go to my photos (CharlieB) I have two views that show what to adjust. There is some type of Loctite on the threads, so it may take some doing to change this tension (if you completely disassemble this adjuster to lubricate, you'll have to reapply a small amount of BLUE Loctite). Both sets of bearings on my focuser were virtually dry and very rough in turning. After I lubed and adjusted the race, everything was great. A WORD OF CAUTION!! If you take the race completely off to lubricate, be ready to catch all the little bearings that WILL come out. I spent 1/2 hour with a magnet scouring the floor because I was careless. You'll have to test any adjustments by putting it all back together again. However, if you get that wobble in the foucuser when you spin the large knob back and forth, your need more tension on the bearing race, so this will be a guide. This also cured the drawtube slipping down all the time. One more hint - leave a tiny gap between the large and small focus knobs so there is absolutely no rubbing. That helps a great deal to smooth out the focuser.
                              > >
                              > > Charlie
                              > >
                              > > --- In William-Optics@yahoogroups.com, "newfieninja" <newfieninja@> wrote:
                              > > >
                              > > > Hi Guys,
                              > > > Thanks for the help.
                              > > >
                              > > > I am starting to believe that I have a bearing issue. Using the allen screw hole in the course focuser knob as a marker, the roughness is always in the exact spot regardless of where the drawtube is located.
                              > > >
                              > > > I have contacted William Optics to see if they can give me any advice on how to diagnose if it is in fact a bearing issue. I have tried micro adjusting the tension but the roughness remains and there is no way to adjust it out, so in my mind it has to be a bearing.
                              > > >
                              > > > I also noticed that with little tension on the focuser, if you let it wind out a little quickly you can notice a wobble in the focuser knobs. I was careful not to let the focuser wind all the way out.
                              > > >
                              > > > Does anyone know if it is difficult to change a bearing in the focuser assembly?
                              > > >
                              > > > Thanks again
                              > > > Lee
                              > > >
                              > > >
                              > > >
                              > > >
                              > > >
                              > > > --- In William-Optics@yahoogroups.com, Sander Pool <sander@> wrote:
                              > > > >
                              > > > >
                              > > > > Lee,
                              > > > >
                              > > > > I don't have an FLT-98 so take this with a grain of salt. The screws on
                              > > > > the top of your focuser do not adjust the tension. They keep the
                              > > > > bearings in place. They should be tight. The two set screws at the
                              > > > > bottom can tilt the focus rod. I would think they would normally be
                              > > > > level. I have not adjusted them as there seems to be no way to know if
                              > > > > you're doing it right. The central set screw is what puts pressure on
                              > > > > the whole assembly and that one I cranked down pretty hard. I don't use
                              > > > > the lock screw at all anymore, in fact it's gone. In my opinion, if
                              > > > > turning the focus knob doesn't move the load then it's too heavy and the
                              > > > > lock screw won't help. It'll just de-focus the camera when tightened.
                              > > > > Opinions will vary on this point I'm sure :)
                              > > > >
                              > > > > Hopefully someone with an FLT-98 can chime in. I assume you've already
                              > > > > contacted WO for help as well.
                              > > > >
                              > > > > Sander
                              > > > >
                              > > > > newfieninja wrote:
                              > > > > >
                              > > > > > Hey all, Does anyone know where I can find a link to a detailed
                              > > > > > description on how to adjust the tension on the newer generation
                              > > > > > refractor crayford focusers?
                              > > > > >
                              > > > > > I have the aluminum tube flt 98 and was having trouble with the micro
                              > > > > > adjuster slipping so I started adjusting the tension and now I have
                              > > > > > tight spots and loose spots when racking the focuser in and out.
                              > > > > >
                              > > > > > There are 2 set screws on the top of the focuser that seem to adjust
                              > > > > > the tension on the roller bearings and then there are 2 set screws on
                              > > > > > the bottom that hold the assembly to the focuser as well as adjust the
                              > > > > > tension. When I have adjusted the tension I have always had the
                              > > > > > drawtube racked out and when the tension is adjusted out the movement
                              > > > > > is very smooth but the focuser will not hold any weight. As I start to
                              > > > > > bring the tension in, the hard and eazy zones are more pronounced and
                              > > > > > it even seems as though the focuser shaft slips on the drawtube plate.
                              > > > > > I probably should never have started to play with the tension but I am
                              > > > > > new to refractors and the damage is done now. I only hope that there
                              > > > > > is an easy way out.
                              > > > > >
                              > > > > > Thanks for the help.
                              > > > > >
                              > > > > > Lee
                              > > > > >
                              > > > > >
                              > > > >
                              > > >
                              > >
                              >
                            • newfieninja
                              Hey Guys, Tim sent me the pictures and the instructions on how to remove the assembly. Even when detached from the focuser, and turning the focus knobs it
                              Message 14 of 14 , Apr 3, 2009
                              • 0 Attachment
                                Hey Guys,

                                Tim sent me the pictures and the instructions on how to remove the assembly. Even when detached from the focuser, and turning the focus knobs it almost completely stops at the exact positon on every revolution. I have just found out that I am leaving the country for 2 months for work and will not have much internet access while I am gone. I am going to send the focuser to WO on Monday before I leave. I will try to update the post when I can. But I have nothing but good things to say about WO customer service. They have promptly responded to every email that I have sent them and offered solutions immediately.

                                Cheers
                                Lee

                                --- In William-Optics@yahoogroups.com, "Charles Brault" <braultc52@...> wrote:
                                >
                                > When I took the assembly off the scope and turned the small and laege knobs, there was plenty of stiction. The Bearings were dry (as I noted before) and the pressure plate was way too tight. When I lubed it and loosened it, it started spinning very freely. Once I had everything right and reassembled it, the external tension set screw (the one with the knurled locking nut) really allowed me to set the tension so the focusing tube stayed put even under quite a load and it still was operating smoothly.
                                >
                                > Charlie
                                > --- In William-Optics@yahoogroups.com, "newfieninja" <newfieninja@> wrote:
                                > >
                                > > Hi Charlie,
                                > >
                                > > Thanks for the info. When you took the shaft assembly off and turned the focus knob was there any stiction or wobble with it spinning freely? I took a look at your pics and will compare them to the pictures that Tim sends me from WO. I will post again after I get them.
                                > >
                                > > Cheers
                                > > Lee
                                > >
                                > > --- In William-Optics@yahoogroups.com, "Charles Brault" <braultc52@> wrote:
                                > > >
                                > > > There probably is nothing wrong with your bearings. There are two sets of bearings in the mechanism - the three large ones which are open and visible, and a set of very small (maybe 20 or so) bearings on the opposite side of the large bearings. There is a an adjuster that varies the tension on the bronze race for these small bearings. If you go to my photos (CharlieB) I have two views that show what to adjust. There is some type of Loctite on the threads, so it may take some doing to change this tension (if you completely disassemble this adjuster to lubricate, you'll have to reapply a small amount of BLUE Loctite). Both sets of bearings on my focuser were virtually dry and very rough in turning. After I lubed and adjusted the race, everything was great. A WORD OF CAUTION!! If you take the race completely off to lubricate, be ready to catch all the little bearings that WILL come out. I spent 1/2 hour with a magnet scouring the floor because I was careless. You'll have to test any adjustments by putting it all back together again. However, if you get that wobble in the foucuser when you spin the large knob back and forth, your need more tension on the bearing race, so this will be a guide. This also cured the drawtube slipping down all the time. One more hint - leave a tiny gap between the large and small focus knobs so there is absolutely no rubbing. That helps a great deal to smooth out the focuser.
                                > > >
                                > > > Charlie
                                > > >
                                > > > --- In William-Optics@yahoogroups.com, "newfieninja" <newfieninja@> wrote:
                                > > > >
                                > > > > Hi Guys,
                                > > > > Thanks for the help.
                                > > > >
                                > > > > I am starting to believe that I have a bearing issue. Using the allen screw hole in the course focuser knob as a marker, the roughness is always in the exact spot regardless of where the drawtube is located.
                                > > > >
                                > > > > I have contacted William Optics to see if they can give me any advice on how to diagnose if it is in fact a bearing issue. I have tried micro adjusting the tension but the roughness remains and there is no way to adjust it out, so in my mind it has to be a bearing.
                                > > > >
                                > > > > I also noticed that with little tension on the focuser, if you let it wind out a little quickly you can notice a wobble in the focuser knobs. I was careful not to let the focuser wind all the way out.
                                > > > >
                                > > > > Does anyone know if it is difficult to change a bearing in the focuser assembly?
                                > > > >
                                > > > > Thanks again
                                > > > > Lee
                                > > > >
                                > > > >
                                > > > >
                                > > > >
                                > > > >
                                > > > > --- In William-Optics@yahoogroups.com, Sander Pool <sander@> wrote:
                                > > > > >
                                > > > > >
                                > > > > > Lee,
                                > > > > >
                                > > > > > I don't have an FLT-98 so take this with a grain of salt. The screws on
                                > > > > > the top of your focuser do not adjust the tension. They keep the
                                > > > > > bearings in place. They should be tight. The two set screws at the
                                > > > > > bottom can tilt the focus rod. I would think they would normally be
                                > > > > > level. I have not adjusted them as there seems to be no way to know if
                                > > > > > you're doing it right. The central set screw is what puts pressure on
                                > > > > > the whole assembly and that one I cranked down pretty hard. I don't use
                                > > > > > the lock screw at all anymore, in fact it's gone. In my opinion, if
                                > > > > > turning the focus knob doesn't move the load then it's too heavy and the
                                > > > > > lock screw won't help. It'll just de-focus the camera when tightened.
                                > > > > > Opinions will vary on this point I'm sure :)
                                > > > > >
                                > > > > > Hopefully someone with an FLT-98 can chime in. I assume you've already
                                > > > > > contacted WO for help as well.
                                > > > > >
                                > > > > > Sander
                                > > > > >
                                > > > > > newfieninja wrote:
                                > > > > > >
                                > > > > > > Hey all, Does anyone know where I can find a link to a detailed
                                > > > > > > description on how to adjust the tension on the newer generation
                                > > > > > > refractor crayford focusers?
                                > > > > > >
                                > > > > > > I have the aluminum tube flt 98 and was having trouble with the micro
                                > > > > > > adjuster slipping so I started adjusting the tension and now I have
                                > > > > > > tight spots and loose spots when racking the focuser in and out.
                                > > > > > >
                                > > > > > > There are 2 set screws on the top of the focuser that seem to adjust
                                > > > > > > the tension on the roller bearings and then there are 2 set screws on
                                > > > > > > the bottom that hold the assembly to the focuser as well as adjust the
                                > > > > > > tension. When I have adjusted the tension I have always had the
                                > > > > > > drawtube racked out and when the tension is adjusted out the movement
                                > > > > > > is very smooth but the focuser will not hold any weight. As I start to
                                > > > > > > bring the tension in, the hard and eazy zones are more pronounced and
                                > > > > > > it even seems as though the focuser shaft slips on the drawtube plate.
                                > > > > > > I probably should never have started to play with the tension but I am
                                > > > > > > new to refractors and the damage is done now. I only hope that there
                                > > > > > > is an easy way out.
                                > > > > > >
                                > > > > > > Thanks for the help.
                                > > > > > >
                                > > > > > > Lee
                                > > > > > >
                                > > > > > >
                                > > > > >
                                > > > >
                                > > >
                                > >
                                >
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