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Re: [GrizHFMinimill] Z-axis stiffness after air spring conversion

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  • Paul A. Beswick
    Mark, This makes sense. In fact thinking that a misalignment between the air spring and its support rod could be the source of the problem I disconnected the
    Message 1 of 25 , Aug 18, 2010
      Mark,

      This makes sense. In fact thinking that a misalignment between the air
      spring and its support rod could be the source of the problem I disconnected
      the rod mount and the problem remained. I nevertheless remounted the column
      support because of exactly what you said, it did not appear straight as the
      holes were too close to the column (note to self - do not assume that
      drawings are accurate, what I did was to cut the actual drawing and glue it
      to the spindle mount casting and get the hole positioning from that. I
      should have known better because I measured the hole spacing on the drawing
      and it was clearly wrong so I adjusted that spacing manually but used the
      drawing to position the holes on the mount relative to the column). Anyway,
      there was fortunately more than enough space and material to fix that
      problem, so I did. However, that was not the source of the stiffness and
      graininess. Nor was it the gibs. I backed those adjustments off completely
      and it still creaked, groaned and juddered up and down and was still stiff.
      Now the problem appears to be largely gone, just a tiny creak remains but
      the action is smooth and I don't need to muscle up to move it up or down.
      Here is why I think it happened.

      Short story - I got my mill many many months ago and it sat in the crate all
      this time since I hadn't built my workshop yet! At the time I bought the
      mill I also ordered the air spring conversion kit. The kit got separated
      from the mill and worse, the air spring got lost. So I ordered a new one
      from LMS. By the time it came I had found the remnants of the original kit
      so I used the support and the rack from that one. It appears that whenever
      the original kit got lost and was pulled apart the rack must have been
      damaged because it is bent. I placed it on the mill table and could clearly
      see the bow along a portion of its length. I'm assuming the mill table is
      relatively flat. The "aha" moment for me came when I removed the rack and
      even with the misaligned support rod, the entire spindle could be moved with
      the wheel without binding and without much effort and also would fall if not
      supported which it wouldn't do when the rack was in.

      This has been a most interesting experience if only because I have become
      now quite accustomed to (and fearless about) stripping the bits and pieces
      of the mill. Not having done any of this kind of work for years it has been
      a very enjoyable (and also frustrating at times :-) ) effort.

      There are small details which I think only start to become clear when you
      have these experiences and make the kinds of mistakes I was making. One of
      the reasons I was certain the support rod was misaligned was that I realized
      that the plastic stop relocated to the left side of the column was being
      squished by the support rod mount because the mount was hitting it midway
      its width at the top of the Z travel. This seemed very odd and I then
      realized that the mount should slide past the stop if the mount was
      positioned differently. There is also an extra inch of travel that can be
      had if an overhanging stop is
      mounted to the horizontal surface at the top of the column. That's for
      another day when I am more experienced, perhaps I can manufacture something
      from a suitable piece of scrap plastic.

      Please forgive the long post and thanks to everyone here who pitched in to
      help.

      Paul (in Jamaica).

      ----- Original Message -----
      From: "Mark Wendt" <mark.wendt@...>
      To: <GrizHFMinimill@yahoogroups.com>
      Sent: Wednesday, August 18, 2010 5:55 AM
      Subject: Re: [GrizHFMinimill] Z-axis stiffness after air spring conversion


      > Paul,
      >
      > Sounds like your gibs are too tight. Try re-adjusting them. Are
      > you sure there's no binding on the air spring - ie, is it set up
      > straight in the column, and bolted on to the head in the right spot?
      > Those are about the only two reasons your Z axis could be stiff.
      >
      > Mark
      >
      > On 08/17/2010 07:46 PM, Paul A. Beswick wrote:
      >> Hi Michael,
      >>
      >> Thanks for the reply. The stiffness I notice in my Z is all the way
      >> through
      >> the range. I really have to grip it firmly to move in any direction. I
      >> wondered whether I did something to cause some loss of alignment and
      >> ended
      >> up with the rack perhaps too close to the gear or whatever engages it. It
      >> was definitely much lighter before. I haven't tried it yet but just to
      >> make
      >> sure its not the shock absorber fighting me I will disconnect that later
      >> and
      >> see how it moves.
      >>
      >> Paul (in Jamaica).
      >>
      >> ----- Original Message -----
      >> From: "michael kolchins"<kwoodhands@...>
      >> To:<GrizHFMinimill@yahoogroups.com>
      >> Sent: Tuesday, August 17, 2010 2:29 PM
      >> Subject: Re: [GrizHFMinimill] Z-axis stiffness after air spring
      >> conversion
      >>
      >>
      >> Paul, my mill is also stiff at the upper height. After the spindle is
      >> pulled
      >> down about 2 or 3 inches it is a lot less stiff.This is fine for my work
      >> as
      >> I do not plan on powering the Z axis.
      >> mike
      >>
      >> --- On Tue, 8/17/10, Paul A. Beswick<pab@...> wrote:
      >>
      >> From: Paul A. Beswick<pab@...>
      >> Subject: [GrizHFMinimill] Z-axis stiffness after air spring conversion
      >> To: GrizHFMinimill@yahoogroups.com
      >> Date: Tuesday, August 17, 2010, 2:02 PM
      >>
      >> Hi all,
      >>
      >> I installed the Air Spring Conversion and all went ok except that the
      >> Z-axis
      >> is now quite stiff. Has anyone experienced this and any suggestions on
      >> how
      >> to reduce the stiffness. It feels stiff enough now that I think a CNC
      >> stepper motor would have problems moving it.
      >>
      >> Paul (in Jamaica).
      >>
      >>
      >>
      >> ------------------------------------
      >>
      >> Yahoo! Groups Links
      >>
      >>
      >>
      >>
      >>
      >>
      >> ------------------------------------
      >>
      >> Yahoo! Groups Links
      >>
      >>
      >>
      >>
      >>
      >
      >
      > ------------------------------------
      >
      > Yahoo! Groups Links
      >
      >
      >
    • Paul A. Beswick
      Michael, Thanks, I located those adjustments. Also I found that what got in the way of adjusting the second screw too was the column locking level which I had
      Message 2 of 25 , Aug 18, 2010
        Michael,

        Thanks, I located those adjustments. Also I found that what got in the way
        of adjusting the second screw too was the column locking level which I had
        to remove completely to get at the adjustment screw easily.

        Paul (in Jamaica).

        ----- Original Message -----
        From: "michael kolchins" <kwoodhands@...>
        To: <GrizHFMinimill@yahoogroups.com>
        Sent: Wednesday, August 18, 2010 12:16 PM
        Subject: Re: [GrizHFMinimill] Z-axis stiffness after air spring conversion


        Paul, you will see four jib adjustment screws on the handle side of the
        mill. Adjust these like the other axis screws. One of the three height
        adjustment handles on the spindle head gets in my way to adjust the second
        screw from the top, I unscrew the this handle til I am finished with the jib
        screws.
        mike

        --- On Tue, 8/17/10, Paul A. Beswick <pab@...> wrote:

        From: Paul A. Beswick <pab@...>
        Subject: Re: [GrizHFMinimill] Z-axis stiffness after air spring conversion
        To: GrizHFMinimill@yahoogroups.com
        Date: Tuesday, August 17, 2010, 8:35 PM

















        Michael,



        I haven't gotten home yet, but I am thinking I have an idea what you are

        talking about. There is a gib strip on one side of the mill column, correct?

        So I imagine its adjustable although I never notice the adjustment screws.

        But thinking about it too it seems reasonable that if there are adjustable

        gibs on X and Y, there should be on Z too! I will have a look in about an

        hour and let you know.



        Paul (in Jamaica).



        ----- Original Message -----

        From: "michael kolchins" <kwoodhands@...>

        To: <GrizHFMinimill@yahoogroups.com>

        Sent: Tuesday, August 17, 2010 7:16 PM

        Subject: Re: [GrizHFMinimill] Z-axis stiffness after air spring conversion



        Paul, I recall the Z axis before the belt conversion was so loose that I

        could move it with one finger. That was too loose I think. Now that I have

        the belt conversion the Z axis is quite tight at the top,but even though I

        said it is a lot less stiff after the first 2 or inches, it is still a much

        stiffer feel all the way to the bottom.

        Could be the jibs are too tight, probably your conversion feels so different

        from the geared version that it seems wrong. Try loosening the jibs and then

        readjust them. That might help some but make sure the jibs are adjusted

        tight enough so the spindle does not move when tightening the column lock.

        mike



        --- On Tue, 8/17/10, Paul A. Beswick <pab@...> wrote:



        From: Paul A. Beswick <pab@...>

        Subject: Re: [GrizHFMinimill] Z-axis stiffness after air spring conversion

        To: GrizHFMinimill@yahoogroups.com

        Date: Tuesday, August 17, 2010, 7:46 PM



        Hi Michael,



        Thanks for the reply. The stiffness I notice in my Z is all the way through



        the range. I really have to grip it firmly to move in any direction. I



        wondered whether I did something to cause some loss of alignment and ended



        up with the rack perhaps too close to the gear or whatever engages it. It



        was definitely much lighter before. I haven't tried it yet but just to make



        sure its not the shock absorber fighting me I will disconnect that later and



        see how it moves.



        Paul (in Jamaica).



        ----- Original Message -----



        From: "michael kolchins" <kwoodhands@...>



        To: <GrizHFMinimill@yahoogroups.com>



        Sent: Tuesday, August 17, 2010 2:29 PM



        Subject: Re: [GrizHFMinimill] Z-axis stiffness after air spring conversion



        Paul, my mill is also stiff at the upper height. After the spindle is pulled



        down about 2 or 3 inches it is a lot less stiff.This is fine for my work as



        I do not plan on powering the Z axis.



        mike



        --- On Tue, 8/17/10, Paul A. Beswick <pab@...> wrote:



        From: Paul A. Beswick <pab@...>



        Subject: [GrizHFMinimill] Z-axis stiffness after air spring conversion



        To: GrizHFMinimill@yahoogroups.com



        Date: Tuesday, August 17, 2010, 2:02 PM



        Hi all,



        I installed the Air Spring Conversion and all went ok except that the Z-axis



        is now quite stiff. Has anyone experienced this and any suggestions on how



        to reduce the stiffness. It feels stiff enough now that I think a CNC



        stepper motor would have problems moving it.



        Paul (in Jamaica).



        ------------------------------------



        Yahoo! Groups Links
      • Chuck
        I installed the air spring kit from LMS a few weeks after getting my X2, which was purchased used. I have had no problem with Z axis stiffness what so ever. I
        Message 3 of 25 , Aug 18, 2010
          I installed the air spring kit from LMS a few weeks after getting my X2, which was purchased used. I have had no problem with Z axis stiffness what so ever. I was a total nube at milling but realized right off the bat that I would benefit from the increased Z travel and elimination of the dreaded X2 Head drop. Best mod I've done to the X2.
          If I can help with pictures, or measurements, let me know.
           
          Chuck in E. TN
        • Mark Wendt
          Paul, Glad you got it figured out. Sometimes these things will have you pulling your hair out trying to troubleshoot the problem. Mark
          Message 4 of 25 , Aug 19, 2010
            Paul,

            Glad you got it figured out. Sometimes these things will have you
            pulling your hair out trying to troubleshoot the problem.

            Mark

            On 08/18/2010 04:38 PM, Paul A. Beswick wrote:
            > Mark,
            >
            > This makes sense. In fact thinking that a misalignment between the air
            > spring and its support rod could be the source of the problem I disconnected
            > the rod mount and the problem remained. I nevertheless remounted the column
            > support because of exactly what you said, it did not appear straight as the
            > holes were too close to the column (note to self - do not assume that
            > drawings are accurate, what I did was to cut the actual drawing and glue it
            > to the spindle mount casting and get the hole positioning from that. I
            > should have known better because I measured the hole spacing on the drawing
            > and it was clearly wrong so I adjusted that spacing manually but used the
            > drawing to position the holes on the mount relative to the column). Anyway,
            > there was fortunately more than enough space and material to fix that
            > problem, so I did. However, that was not the source of the stiffness and
            > graininess. Nor was it the gibs. I backed those adjustments off completely
            > and it still creaked, groaned and juddered up and down and was still stiff.
            > Now the problem appears to be largely gone, just a tiny creak remains but
            > the action is smooth and I don't need to muscle up to move it up or down.
            > Here is why I think it happened.
            >
            > Short story - I got my mill many many months ago and it sat in the crate all
            > this time since I hadn't built my workshop yet! At the time I bought the
            > mill I also ordered the air spring conversion kit. The kit got separated
            > from the mill and worse, the air spring got lost. So I ordered a new one
            > from LMS. By the time it came I had found the remnants of the original kit
            > so I used the support and the rack from that one. It appears that whenever
            > the original kit got lost and was pulled apart the rack must have been
            > damaged because it is bent. I placed it on the mill table and could clearly
            > see the bow along a portion of its length. I'm assuming the mill table is
            > relatively flat. The "aha" moment for me came when I removed the rack and
            > even with the misaligned support rod, the entire spindle could be moved with
            > the wheel without binding and without much effort and also would fall if not
            > supported which it wouldn't do when the rack was in.
            >
            > This has been a most interesting experience if only because I have become
            > now quite accustomed to (and fearless about) stripping the bits and pieces
            > of the mill. Not having done any of this kind of work for years it has been
            > a very enjoyable (and also frustrating at times :-) ) effort.
            >
            > There are small details which I think only start to become clear when you
            > have these experiences and make the kinds of mistakes I was making. One of
            > the reasons I was certain the support rod was misaligned was that I realized
            > that the plastic stop relocated to the left side of the column was being
            > squished by the support rod mount because the mount was hitting it midway
            > its width at the top of the Z travel. This seemed very odd and I then
            > realized that the mount should slide past the stop if the mount was
            > positioned differently. There is also an extra inch of travel that can be
            > had if an overhanging stop is
            > mounted to the horizontal surface at the top of the column. That's for
            > another day when I am more experienced, perhaps I can manufacture something
            > from a suitable piece of scrap plastic.
            >
            > Please forgive the long post and thanks to everyone here who pitched in to
            > help.
            >
            > Paul (in Jamaica).
            >
            > ----- Original Message -----
            > From: "Mark Wendt"<mark.wendt@...>
            > To:<GrizHFMinimill@yahoogroups.com>
            > Sent: Wednesday, August 18, 2010 5:55 AM
            > Subject: Re: [GrizHFMinimill] Z-axis stiffness after air spring conversion
            >
            >
            >
            >> Paul,
            >>
            >> Sounds like your gibs are too tight. Try re-adjusting them. Are
            >> you sure there's no binding on the air spring - ie, is it set up
            >> straight in the column, and bolted on to the head in the right spot?
            >> Those are about the only two reasons your Z axis could be stiff.
            >>
            >> Mark
            >>
            >> On 08/17/2010 07:46 PM, Paul A. Beswick wrote:
            >>
            >>> Hi Michael,
            >>>
            >>> Thanks for the reply. The stiffness I notice in my Z is all the way
            >>> through
            >>> the range. I really have to grip it firmly to move in any direction. I
            >>> wondered whether I did something to cause some loss of alignment and
            >>> ended
            >>> up with the rack perhaps too close to the gear or whatever engages it. It
            >>> was definitely much lighter before. I haven't tried it yet but just to
            >>> make
            >>> sure its not the shock absorber fighting me I will disconnect that later
            >>> and
            >>> see how it moves.
            >>>
            >>> Paul (in Jamaica).
            >>>
            >>> ----- Original Message -----
            >>> From: "michael kolchins"<kwoodhands@...>
            >>> To:<GrizHFMinimill@yahoogroups.com>
            >>> Sent: Tuesday, August 17, 2010 2:29 PM
            >>> Subject: Re: [GrizHFMinimill] Z-axis stiffness after air spring
            >>> conversion
            >>>
            >>>
            >>> Paul, my mill is also stiff at the upper height. After the spindle is
            >>> pulled
            >>> down about 2 or 3 inches it is a lot less stiff.This is fine for my work
            >>> as
            >>> I do not plan on powering the Z axis.
            >>> mike
            >>>
            >>> --- On Tue, 8/17/10, Paul A. Beswick<pab@...> wrote:
            >>>
            >>> From: Paul A. Beswick<pab@...>
            >>> Subject: [GrizHFMinimill] Z-axis stiffness after air spring conversion
            >>> To: GrizHFMinimill@yahoogroups.com
            >>> Date: Tuesday, August 17, 2010, 2:02 PM
            >>>
            >>> Hi all,
            >>>
            >>> I installed the Air Spring Conversion and all went ok except that the
            >>> Z-axis
            >>> is now quite stiff. Has anyone experienced this and any suggestions on
            >>> how
            >>> to reduce the stiffness. It feels stiff enough now that I think a CNC
            >>> stepper motor would have problems moving it.
            >>>
            >>> Paul (in Jamaica).
            >>>
            >>>
            >>>
            >>> ------------------------------------
            >>>
            >>> Yahoo! Groups Links
            >>>
            >>>
            >>>
            >>>
            >>>
            >>>
            >>> ------------------------------------
            >>>
            >>> Yahoo! Groups Links
            >>>
            >>>
            >>>
            >>>
            >>>
            >>>
            >>
            >> ------------------------------------
            >>
            >> Yahoo! Groups Links
            >>
            >>
            >>
            >>
            >
            >
            > ------------------------------------
            >
            > Yahoo! Groups Links
            >
            >
            >
            >
            >
          • sigp2101
            Does anyone know how many pounds or kilos are those air spring rated. I want to buy one in local auto parts store and modify my mill. Thanks!
            Message 5 of 25 , Sep 3 12:17 PM
              Does anyone know how many pounds or kilos are those air spring rated. I want to buy one in local auto parts store and modify my mill.

              Thanks!


              --- In GrizHFMinimill@yahoogroups.com, "Chuck" <chunk07@...> wrote:
              >
              > I installed the air spring kit from LMS a few weeks after getting my X2, which was purchased used. I have had no problem with Z axis stiffness what so ever. I was a total nube at milling but realized right off the bat that I would benefit from the increased Z travel and elimination of the dreaded X2 Head drop. Best mod I've done to the X2.
              > If I can help with pictures, or measurements, let me know.
              >
              > Chuck in E. TN
              >
            • upand_at_them
              Well, the kit from LMS says it has about 35 pounds of force .
              Message 6 of 25 , Sep 6 1:26 PM
                Well, the kit from LMS says it has "about 35 pounds of force".

                --- In GrizHFMinimill@yahoogroups.com, "sigp2101" <sigp2101@...> wrote:
                >
                > Does anyone know how many pounds or kilos are those air spring rated. I want to buy one in local auto parts store and modify my mill.
              • paul_in_pittsfield
                You can get air springs in quite a range of lengths and force ratings from Service Plus Distributors, Inc., of Bensalem, PA. (http://www.spdhardware.com/)
                Message 7 of 25 , Sep 7 7:14 AM
                  You can get air springs in quite a range of lengths and force ratings from Service Plus Distributors, Inc., of Bensalem, PA. (http://www.spdhardware.com/)

                  Before you decide, see "Airspring.pdf" in "Paul in Pittsfield's Mill Mods" at http://tinyurl.com/248gzhl

                  Paul in Pittsfield

                  --- In GrizHFMinimill@yahoogroups.com, "sigp2101" <sigp2101@...> wrote:
                  >
                  > Does anyone know how many pounds or kilos are those air spring rated. I want to buy one in local auto parts store and modify my mill.
                  >
                  > Thanks!
                • redbaron192redbaron192
                  35 pounds force sounds about right. I used a Peugeot bonnet strut - just the right length, stroke, diameter and force for my Amadeal XJ12-300 (similar to the
                  Message 8 of 25 , Sep 7 9:00 AM
                    35 pounds force sounds about right.

                    I used a Peugeot bonnet strut - just the right length, stroke, diameter and force for my Amadeal XJ12-300 (similar to the Big Dog mill).

                    http://www.cargasstruts.co.uk/car_boot_bonnet_gas_struts.php/cPath/1/products_id/88?osCsid=5f2d27f268fb7593304d9cbf3aefd733

                    Works a treat :o)

                    --- In GrizHFMinimill@yahoogroups.com, "sigp2101" <sigp2101@...> wrote:
                    >
                    > Does anyone know how many pounds or kilos are those air spring rated. I want to buy one in local auto parts store and modify my mill.
                    >
                    > Thanks!
                    >
                    >
                    > --- In GrizHFMinimill@yahoogroups.com, "Chuck" <chunk07@> wrote:
                    > >
                    > > I installed the air spring kit from LMS a few weeks after getting my X2, which was purchased used. I have had no problem with Z axis stiffness what so ever. I was a total nube at milling but realized right off the bat that I would benefit from the increased Z travel and elimination of the dreaded X2 Head drop. Best mod I've done to the X2.
                    > > If I can help with pictures, or measurements, let me know.
                    > >
                    > > Chuck in E. TN
                    > >
                    >
                  • gerry waclawiak
                    The sad part of this is that the standard mills several years ago used to come fitted with a gas strut with enhanced z axis travel and they then improved
                    Message 9 of 25 , Sep 8 4:03 AM
                      The sad part of this is that the standard mills several years ago used to come fitted with a gas strut with enhanced z axis travel and they then "improved" them (presumably to cut costs) by fitting the crappy torsion arm which gets in the way, reduces z travel and has attendant head drop problems.
                       
                      Now you have to do a mod at considerable greater cost than was saved.
                       
                      Such is progress
                       
                      Gerry
                      Leeds UK
                       

                      To: GrizHFMinimill@yahoogroups.com
                      From: casiobearing@...
                      Date: Tue, 7 Sep 2010 16:00:15 +0000
                      Subject: [GrizHFMinimill] Re:Z-axis stiffness after air spring conversion

                       
                      35 pounds force sounds about right.

                      I used a Peugeot bonnet strut - just the right length, stroke, diameter and force for my Amadeal XJ12-300 (similar to the Big Dog mill).

                      http://www.cargasstruts.co.uk/car_boot_bonnet_gas_struts.php/cPath/1/products_id/88?osCsid=5f2d27f268fb7593304d9cbf3aefd733

                      Works a treat :o)

                      --- In GrizHFMinimill@yahoogroups.com, "sigp2101" <sigp2101@...> wrote:
                      >
                      > Does anyone know how many pounds or kilos are those air spring rated. I want to buy one in local auto parts store and modify my mill.
                      >
                      > Thanks!
                      >
                      >
                      > --- In GrizHFMinimill@yahoogroups.com, "Chuck" <chunk07@> wrote:
                      > >
                      > > I installed the air spring kit from LMS a few weeks after getting my X2, which was purchased used. I have had no problem with Z axis stiffness what so ever. I was a total nube at milling but realized right off the bat that I would benefit from the increased Z travel and elimination of the dreaded X2 Head drop. Best mod I've done to the X2.
                      > > If I can help with pictures, or measurements, let me know.
                      > >
                      > > Chuck in E. TN
                      > >
                      >


                    • David
                      the LMS spring is 35 pounds
                      Message 10 of 25 , Sep 8 6:10 AM
                        the LMS spring is 35 pounds

                        --- In GrizHFMinimill@yahoogroups.com, "sigp2101" <sigp2101@...> wrote:
                        >
                        > Does anyone know how many pounds or kilos are those air spring rated. I want to buy one in local auto parts store and modify my mill.
                        >
                        > Thanks!
                        >
                        >
                        > --- In GrizHFMinimill@yahoogroups.com, "Chuck" <chunk07@> wrote:
                        > >
                        > > I installed the air spring kit from LMS a few weeks after getting my X2, which was purchased used. I have had no problem with Z axis stiffness what so ever. I was a total nube at milling but realized right off the bat that I would benefit from the increased Z travel and elimination of the dreaded X2 Head drop. Best mod I've done to the X2.
                        > > If I can help with pictures, or measurements, let me know.
                        > >
                        > > Chuck in E. TN
                        > >
                        >
                      • David
                        oh yea forgot to add, that I looked at all the springs that the auto shops had. I couldn t find one long enough to get the full travel that was needed. So I
                        Message 11 of 25 , Sep 8 6:15 AM
                          oh yea forgot to add, that I looked at all the springs that the auto shops had. I couldn't find one long enough to get the full travel that was needed. So I went with the LMS kit for like 40 bucks which didn't fit my mill just exactly but worked out ok.
                          From what I learned doing my mill if I had to do another one I would buy the kit, that way you get all the parts if you have the right mill, and you get the extra long rack gear that your going to need.
                          jut my 2 bucks worth!!

                          David

                          --- In GrizHFMinimill@yahoogroups.com, "sigp2101" <sigp2101@...> wrote:
                          >
                          > Does anyone know how many pounds or kilos are those air spring rated. I want to buy one in local auto parts store and modify my mill.
                          >
                          > Thanks!
                          >
                          >
                          > --- In GrizHFMinimill@yahoogroups.com, "Chuck" <chunk07@> wrote:
                          > >
                          > > I installed the air spring kit from LMS a few weeks after getting my X2, which was purchased used. I have had no problem with Z axis stiffness what so ever. I was a total nube at milling but realized right off the bat that I would benefit from the increased Z travel and elimination of the dreaded X2 Head drop. Best mod I've done to the X2.
                          > > If I can help with pictures, or measurements, let me know.
                          > >
                          > > Chuck in E. TN
                          > >
                          >
                        • redbaron192redbaron192
                          Yes i was thinking about that whilst doing the mod.... I can only think that a gas strut is a precision manufactured item and therefore quite a cost compared
                          Message 12 of 25 , Sep 8 8:51 AM
                            Yes i was thinking about that whilst doing the mod.... I can only think that a gas strut is a precision manufactured item and therefore quite a cost compared to all the bits required to implement the spring arm solution.

                            --- In GrizHFMinimill@yahoogroups.com, gerry waclawiak <gerrywac@...> wrote:
                            >
                            >
                            > The sad part of this is that the standard mills several years ago used to come fitted with a gas strut with enhanced z axis travel and they then "improved" them (presumably to cut costs) by fitting the crappy torsion arm which gets in the way, reduces z travel and has attendant head drop problems.
                            >
                            >
                            >
                            > Now you have to do a mod at considerable greater cost than was saved.
                            >
                            >
                            >
                            > Such is progress
                            >
                            >
                            >
                            > Gerry
                            >
                            > Leeds UK
                            >
                            >
                            >
                            > To: GrizHFMinimill@yahoogroups.com
                            > From: casiobearing@...
                            > Date: Tue, 7 Sep 2010 16:00:15 +0000
                            > Subject: [GrizHFMinimill] Re:Z-axis stiffness after air spring conversion
                            >
                            >
                            >
                            >
                            >
                            >
                            > 35 pounds force sounds about right.
                            >
                            > I used a Peugeot bonnet strut - just the right length, stroke, diameter and force for my Amadeal XJ12-300 (similar to the Big Dog mill).
                            >
                            > http://www.cargasstruts.co.uk/car_boot_bonnet_gas_struts.php/cPath/1/products_id/88?osCsid=5f2d27f268fb7593304d9cbf3aefd733
                            >
                            > Works a treat :o)
                            >
                            > --- In GrizHFMinimill@yahoogroups.com, "sigp2101" <sigp2101@> wrote:
                            > >
                            > > Does anyone know how many pounds or kilos are those air spring rated. I want to buy one in local auto parts store and modify my mill.
                            > >
                            > > Thanks!
                            > >
                            > >
                            > > --- In GrizHFMinimill@yahoogroups.com, "Chuck" <chunk07@> wrote:
                            > > >
                            > > > I installed the air spring kit from LMS a few weeks after getting my X2, which was purchased used. I have had no problem with Z axis stiffness what so ever. I was a total nube at milling but realized right off the bat that I would benefit from the increased Z travel and elimination of the dreaded X2 Head drop. Best mod I've done to the X2.
                            > > > If I can help with pictures, or measurements, let me know.
                            > > >
                            > > > Chuck in E. TN
                            > > >
                            > >
                            >
                          • Richard
                            Use a bonnet/hood spring from a small car that has 2 struts to hold the bonnet up. Pergot 206 or small citreon for example these have a compressing force of
                            Message 13 of 25 , Sep 10 10:08 AM
                              Use a bonnet/hood spring from a small car that has 2 struts to hold the bonnet up. Pergot 206 or small citreon for example these have a compressing force of about 35lbs. I have a short video of mine if it helps. I bought a pair of these off of ebay for about £5

                              http://www.youtube.com/watch?v=CuogO3W1mh8

                              Regards Rich

                              --- In GrizHFMinimill@yahoogroups.com, "Paul A. Beswick" <pab@...> wrote:
                              >
                              > Hi all,
                              >
                              > I installed the Air Spring Conversion and all went ok except that the Z-axis
                              > is now quite stiff. Has anyone experienced this and any suggestions on how
                              > to reduce the stiffness. It feels stiff enough now that I think a CNC
                              > stepper motor would have problems moving it.
                              >
                              > Paul (in Jamaica).
                              >
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