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LX-200 classic - dec. bearing question

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  • tom_krajci
    New photos/text at Original style LX-200 Classic dec. sleeve bearing (with
    Message 1 of 6 , Jul 1, 2009
      New photos/text at
      <http://tech.groups.yahoo.com/group/Meade-Uncensored/files/LX200-OTA-disassembly/>

      Original style LX-200 Classic dec. sleeve bearing (with thust
      bearing/washers behind, not visible).

      New style LX-200 Classic dec. roller bearing. Note that fork arm is
      NOT bored to accept the bearing's outer diameter. It appears to be
      mounted to the inside of the fork arm surface instead.

      Another perspective to show Meade roller bearing mounting. Did they
      merely glue the bearing to the fork's inner surface? Or did they do
      something else?

      Thanks in advance.

      --
      -------------------------------------------
      Tom Krajci
      Cloudcroft, New Mexico
      http://picasaweb.google.com/tom.krajci

      Center for Backyard Astrophysics (CBA)
      http://cbastro.org/ CBA New Mexico

      American Association of Variable Star
      Observers (AAVSO): KTC http://www.aavso.org/
      -------------------------------------------
    • Juan Breuer
      Tom, Not an expert, but I think that they bored for the inner side of the forks because the forks are making a little presure into the OTA and in that way it
      Message 2 of 6 , Jul 1, 2009
        Tom,

        Not an expert, but I think that they bored for the inner side of the forks because the forks are making a little presure into the OTA and in that way it has a hard stop for the bearings. If they where in the outerside perhaps it could produce another issue with the wear and lateral displacement of the OTA.

        I think that the later GPS model uses roller bearings by pairs on each fork. One on each side. If I have to mod my Clasic LX200 for adding roller bearings, for sure I will bore in the inner side so I use the not bored outer side as hard stop for the bearing. Or go for a more expensive modification and add pair of diagonal roller bearings so they supports better all the weigh when they are in polar position.

        Regards,
        Juan.




        ________________________________
        From: tom_krajci <tom_krajci@...>
        To: Meade-Uncensored@yahoogroups.com
        Sent: Wednesday, July 1, 2009 11:30:34 AM
        Subject: [MeadeUncensored] LX-200 classic - dec. bearing question





        New photos/text at
        <http://tech. groups.yahoo. com/group/ Meade-Uncensored /files/LX200- OTA-disassembly/>

        Original style LX-200 Classic dec. sleeve bearing (with thust
        bearing/washers behind, not visible).

        New style LX-200 Classic dec. roller bearing. Note that fork arm is
        NOT bored to accept the bearing's outer diameter. It appears to be
        mounted to the inside of the fork arm surface instead.

        Another perspective to show Meade roller bearing mounting. Did they
        merely glue the bearing to the fork's inner surface? Or did they do
        something else?

        Thanks in advance.

        --
        ------------ --------- --------- --------- ----
        Tom Krajci
        Cloudcroft, New Mexico
        http://picasaweb. google.com/ tom.krajci

        Center for Backyard Astrophysics (CBA)
        http://cbastro. org/ CBA New Mexico

        American Association of Variable Star
        Observers (AAVSO): KTC http://www.aavso. org/
        ------------ --------- --------- --------- ----




        [Non-text portions of this message have been removed]
      • Andy Eskelson
        Tom, you might find this site of use. It s all about the GPS rather than the classic, but the CAD drawings are first class, The bearing housing shows a small
        Message 3 of 6 , Jul 1, 2009
          Tom,

          you might find this site of use. It's all about the GPS rather than the
          classic, but the CAD drawings are first class, The bearing housing shows
          a small ridge in the centre. It could be that the early LX did not have
          a ridge and the bearing was simply fixed with loctite.

          http://www.crcm.net/lx200gps8/index.htm


          Andy






          On Wed, 01 Jul 2009 14:30:34 -0000
          "tom_krajci" <tom_krajci@...> wrote:

          > New photos/text at
          > <http://tech.groups.yahoo.com/group/Meade-Uncensored/files/LX200-OTA-disassembly/>
          >
          > Original style LX-200 Classic dec. sleeve bearing (with thust
          > bearing/washers behind, not visible).
          >
          > New style LX-200 Classic dec. roller bearing. Note that fork arm is
          > NOT bored to accept the bearing's outer diameter. It appears to be
          > mounted to the inside of the fork arm surface instead.
          >
          > Another perspective to show Meade roller bearing mounting. Did they
          > merely glue the bearing to the fork's inner surface? Or did they do
          > something else?
          >
          > Thanks in advance.
          >
          > --
          > -------------------------------------------
          > Tom Krajci
          > Cloudcroft, New Mexico
          > http://picasaweb.google.com/tom.krajci
          >
          > Center for Backyard Astrophysics (CBA)
          > http://cbastro.org/ CBA New Mexico
          >
          > American Association of Variable Star
          > Observers (AAVSO): KTC http://www.aavso.org/
          > -------------------------------------------
          >
        • tom_krajci
          ... Yes, I think you are right. I have removed the forks from the sleeve- bearing LX-200 and compared them to a Meade roller-bearing model. It appears the
          Message 4 of 6 , Jul 1, 2009
            --- In Meade-Uncensored@yahoogroups.com, Juan Breuer <jjbreuer@...> wrote:
            >
            >...I think that they bored for the inner side of the forks because
            > the forks are making a little presure into the OTA and in that way
            > it has a hard stop for the bearings.

            Yes, I think you are right. I have removed the forks from the sleeve-
            bearing LX-200 and compared them to a Meade roller-bearing model. It
            appears the inside of the fork arm was bored to a depth of about 5/8
            inches (0.625 inches) to accept the roller bearing unit. Yes, the
            outer part of the fork serves as a hard stop.

            >...If I have to mod my Clasic LX200 for adding roller bearings, for
            > sure I will bore in the inner side so I use the not bored outer
            > side as hard stop for the bearing. Or go for a more expensive
            > modification and add pair of diagonal roller bearings so they
            > supports better all the weigh when they are in polar position.

            Do you mean tapered roller bearings? They may fit the shaft (or hard
            shaft sleeve), but their outer diameter is larger than the section of
            the fork that has extra thickness to carry a bearing unit. This will
            make it difficult to mount the bearings properly

            The needle bearing from http://www.mcmaster.com, part number 5905K29
            has an OD of 1 1/2 inches, and is 3/4 inches wide. This will fit
            within the 2-inch diameter portion of the fork that is 1-inch thick.

            I just need to talk to a local machine shop to work out the details,
            and double check dimensions and clearance/interference issues so that
            it will re-assemble correctly.

            --
            -------------------------------------------
            Tom Krajci
            Cloudcroft, New Mexico
            http://picasaweb.google.com/tom.krajci

            Center for Backyard Astrophysics (CBA)
            http://cbastro.org/ CBA New Mexico

            American Association of Variable Star
            Observers (AAVSO): KTC http://www.aavso.org/
            -------------------------------------------
          • Juan Breuer
            Hi Tom, I suppose that you saw this page: http://www.mapug-astronomy.net/ragreiner/decfixmajor.html Yes, I mean tapered, but as you indicate it s not practical
            Message 5 of 6 , Jul 1, 2009
              Hi Tom,

              I suppose that you saw this page: http://www.mapug-astronomy.net/ragreiner/decfixmajor.html

              Yes, I mean tapered, but as you indicate it's not practical mod because the space and also looks like a standard roller bearing could be enought. Many people already made the mod to their Classics.

              Juan.




              ________________________________
              From: tom_krajci <tom_krajci@...>
              To: Meade-Uncensored@yahoogroups.com
              Sent: Wednesday, July 1, 2009 7:43:30 PM
              Subject: Re: [MeadeUncensored] LX-200 classic - dec. bearing question





              --- In Meade-Uncensored@ yahoogroups. com, Juan Breuer <jjbreuer@.. .> wrote:
              >
              >...I think that they bored for the inner side of the forks because
              > the forks are making a little presure into the OTA and in that way
              > it has a hard stop for the bearings.

              Yes, I think you are right. I have removed the forks from the sleeve-
              bearing LX-200 and compared them to a Meade roller-bearing model. It
              appears the inside of the fork arm was bored to a depth of about 5/8
              inches (0.625 inches) to accept the roller bearing unit. Yes, the
              outer part of the fork serves as a hard stop.

              >...If I have to mod my Clasic LX200 for adding roller bearings, for
              > sure I will bore in the inner side so I use the not bored outer
              > side as hard stop for the bearing. Or go for a more expensive
              > modification and add pair of diagonal roller bearings so they
              > supports better all the weigh when they are in polar position.

              Do you mean tapered roller bearings? They may fit the shaft (or hard
              shaft sleeve), but their outer diameter is larger than the section of
              the fork that has extra thickness to carry a bearing unit. This will
              make it difficult to mount the bearings properly

              The needle bearing from http://www.mcmaster.com, part number 5905K29
              has an OD of 1 1/2 inches, and is 3/4 inches wide. This will fit
              within the 2-inch diameter portion of the fork that is 1-inch thick.

              I just need to talk to a local machine shop to work out the details,
              and double check dimensions and clearance/interfere nce issues so that
              it will re-assemble correctly.

              --
              ------------ --------- --------- --------- ----
              Tom Krajci
              Cloudcroft, New Mexico
              http://picasaweb. google.com/ tom.krajci

              Center for Backyard Astrophysics (CBA)
              http://cbastro. org/ CBA New Mexico

              American Association of Variable Star
              Observers (AAVSO): KTC http://www.aavso. org/
              ------------ --------- --------- --------- ----




              [Non-text portions of this message have been removed]
            • tom_krajci
              ... Part two - now that I ve disconnected OTA/stub axles/forks...the thrust bearing on one fork arm...did not have a steel thrust bearing washer between the
              Message 6 of 6 , Jul 2, 2009
                --- In Meade-Uncensored@yahoogroups.com, "tom_krajci" <tom_krajci@...> wrote:
                >
                > New photos/text at
                > <http://tech.groups.yahoo.com/group/Meade-Uncensored/files/LX200-OTA-disassembly/>
                >
                > Original style LX-200 Classic dec. sleeve bearing (with thust
                > bearing/washers behind, not visible).

                Part two - now that I've disconnected OTA/stub axles/forks...the
                thrust bearing on one fork arm...did not have a steel thrust bearing
                washer between the bearing and the aluminum fork arm surface.

                Result? Galling of the aluminum fork arm surface, uneven bearing
                motion, extra friction. (But the steel thrust bearing rollers seem
                undamaged.)

                Easy enough to fix...clean/regrease the bearing, and put a proper
                thrust bearing washer in place when I reassemble.

                I don't think the original owner ever took apart the fork bearings,
                so I place blame on Meade factory assembly.

                --
                -------------------------------------------
                Tom Krajci
                Cloudcroft, New Mexico
                http://picasaweb.google.com/tom.krajci

                Center for Backyard Astrophysics (CBA)
                http://cbastro.org/ CBA New Mexico

                American Association of Variable Star
                Observers (AAVSO): KTC http://www.aavso.org/
                -------------------------------------------
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