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Re: Column bracing

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  • mmjarz
    AL- I have been looking at posts in both the Mill group(this one) & the lathe group about mill column stiffining. I gather from the postings that loading the
    Message 1 of 25 , May 1, 2002
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      AL-
      I have been looking at posts in both the Mill group(this one) & the
      lathe group about mill column stiffining. I gather from the postings
      that loading the column with shot pellets ( shotgun shell pellets )
      has REDUCED CHATTER. Not being a physicist - I think it has
      something to do with harminic vibration - & the fact that the shot is
      almost fluid inside the column. the mass of shot is free to move at
      a different "period" from the column & therefore has a dampening
      effect on the column vibration - this absorbs the motion instead of
      allowing it to deflect the tool at the milling surface >> no chatter.

      I have thought that if one were to mount a 2 foot by 2 foot plate
      against the rear surface of the column ( with a hole to accomidate
      the pivot bolt - relocate the big nut & washer to the outside of the
      plate ) so that the column is still free to pivot side to side -
      but "up against the wall" created by the plate, then the column would
      have stiffining thru all positions. You would have to install
      bracing from the top edge of the plate diagonally downward to the
      extended base plate behind the mill. Stiffining of the top edge with
      an angle bar& mounting the bottom edge to the base plate with a
      similar angle bar. Squareness would be a paramount issue of course.
      - Dave - Billings MT

      --- In GrizHFMinimill@y..., "fromday2" <aldayis@a...> wrote:
      > Rick / Dave / Ken (and others, if any). How does the column
      bracing
      > work out in use? I seem to mostly cut hard stuff and sure would
      like
      > to reduce the chatter. I have been thinking of bracing the column
      > but as I have been moving the mill from shop to shop I have not yet
      > taken the step. I had been thinking more along the lines of Ken's
      > diagnal braces in the back, perhaps with a plate about 6 inches
      wide
      > up the back of the coulmn to stiffen it from left to right.
      However,
      > I have noted that much of the movement in my mill is in the
      > headstock, so I have wondered if stiffing the column would be a
      major
      > improvement. I do keep the gibs quite snug.
      >
      --snip----------
    • fromday2
      Dave, makes sense to me, loose shot should dampen resonances in the column. I think the REX mill has shot that is held in place by Anocast(?) material which I
      Message 2 of 25 , May 1, 2002
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        Dave, makes sense to me, loose shot should dampen resonances in the
        column. I think the REX mill has shot that is held in place by
        Anocast(?) material which I assume expands when it sets, which
        should stiffen the column and the greater mass should lower the
        resonance point. However I do not recall testimonials from list
        members that have installed shot or have personally compared the REX
        mill to the other mini-mills. I know Rick Kruger was looking for a
        source of Anocast but did not hear if he was successful.

        I am about to build a new, improved, repacement bench for the mill;
        wood, with shelves, pegboard, steel wheels, and I will use a 1/2"
        steel base plate under the mill, a back plate extending about 16" up
        the column and a diagonal back brace similar to the kind Ken used. I
        would attach the column to the back plate / back brace and would not
        miss the column pivoting feature.

        I might do the shot trick, and perhaps add Anocast if it is
        available. I better make a strong bench.

        --- In GrizHFMinimill@y..., "mmjarz" <mmjarz@y...> wrote:
        > AL-
        > I have been looking at posts in both the Mill group(this one) & the
        > lathe group about mill column stiffining. I gather from the
        postings
        > that loading the column with shot pellets ( shotgun shell pellets )
        > has REDUCED CHATTER

        >snip<
      • mmjarz
        I agree- My mill is setting on a 3 0 solid core door on top of a wooden, table height bench I built years ago. My base plate is only 3/8 thick - 27 front to
        Message 3 of 25 , May 1, 2002
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          I agree-
          My mill is setting on a 3'0" solid core door on top of a wooden,
          table height bench I built years ago. My base plate is only 3/8"
          thick - 27" front to back - I'm going to load up with shot & leave it
          loose ( plug top & bottom) - & then I'm going to start using the mill.

          enough tinkering........
          -dave

          --- In GrizHFMinimill@y..., "fromday2" <aldayis@a...> wrote:
          > Dave, makes sense to me, loose shot should dampen resonances in the
          > column. I think the REX mill has shot that is held in place by
          > Anocast(?) material which I assume expands when it sets, which
          > should stiffen the column and the greater mass should lower the
          > resonance point. However I do not recall testimonials from list
          > members that have installed shot or have personally compared the
          REX
          > mill to the other mini-mills. I know Rick Kruger was looking for a
          > source of Anocast but did not hear if he was successful.
          >
          > I am about to build a new, improved, repacement bench for the mill;
          > wood, with shelves, pegboard, steel wheels, and I will use a 1/2"
          > steel base plate under the mill, a back plate extending about 16"
          up
          > the column and a diagonal back brace similar to the kind Ken used.
          I
          > would attach the column to the back plate / back brace and would
          not
          > miss the column pivoting feature.
          >
          > I might do the shot trick, and perhaps add Anocast if it is
          > available. I better make a strong bench.
          >
          > --- In GrizHFMinimill@y..., "mmjarz" <mmjarz@y...> wrote:
          > > AL-
          > > I have been looking at posts in both the Mill group(this one) &
          the
          > > lathe group about mill column stiffining. I gather from the
          > postings
          > > that loading the column with shot pellets ( shotgun shell
          pellets )
          > > has REDUCED CHATTER
          >
          > >snip<
        • Brian Pitt
          heres the URL for anocast http://www.anorad.com/onlineCatalog/anocastComposite.htm or check http://www.phillyresins.com for the same kind of stuff there is a
          Message 4 of 25 , May 1, 2002
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            heres the URL for anocast
            http://www.anorad.com/onlineCatalog/anocastComposite.htm

            or check http://www.phillyresins.com for the same kind of stuff

            there is a good overview article on these kinds of epoxy-granite
            composites here
            http://www.machineshopguide.com/pdf/600/Castpolymer.pdf

            and there is yet another chatter reducing idea over here that
            might be just the thing for the mini's column
            http://www.phillyresins.com/products/vibradamp.htm

            after looking over some of this stuff and doing a few tests I think
            you could probably get "good'nuff" results with hardware store
            epoxies and a washed & dried sand/gravel mix

            HTH
            Brian
          • Rick Kruger
            Anocast isn t an option, so there isn t much point in looking at it. I talked with them when looking into these things. Anocast only does it for OEMs in
            Message 5 of 25 , May 1, 2002
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              Anocast isn't an option, so there isn't much point in looking at it. I
              talked with them when looking into these things. Anocast only does it for
              OEMs in production mode. They don't sell it for retail users. Move on to
              the other options.

              Rick K.
              Portland, OR

              At 08:09 PM 5/1/02 -0700, you wrote:
              >heres the URL for anocast
              >http://www.anorad.com/onlineCatalog/anocastComposite.htm
              >
              >or check http://www.phillyresins.com for the same kind of stuff
              >
              >there is a good overview article on these kinds of epoxy-granite
              >composites here
              >http://www.machineshopguide.com/pdf/600/Castpolymer.pdf
              >
              >and there is yet another chatter reducing idea over here that
              >might be just the thing for the mini's column
              >http://www.phillyresins.com/products/vibradamp.htm
              >
              >after looking over some of this stuff and doing a few tests I think
              >you could probably get "good'nuff" results with hardware store
              >epoxies and a washed & dried sand/gravel mix
              >
              >HTH
              >Brian
            • fromday2
              Intresting information. I assumed that Anocast was some propriatary material somewhat along the lines of unobtanium, and did not look further than a Google
              Message 6 of 25 , May 1, 2002
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                Intresting information. I assumed that Anocast was some propriatary
                material somewhat along the lines of unobtanium, and did not look
                further than a Google search, which did not inspire me to look
                further. I think you have a good idea and it might be worthwhile to
                do some testing with a piece of pipe and some ordinary resin. Thanks

                Al Day

                --- In GrizHFMinimill@y..., Brian Pitt <bfp@e...> wrote:
                > heres the URL for anocast
                > http://www.anorad.com/onlineCatalog/anocastComposite.htm
                >
                > or check http://www.phillyresins.com for the same kind of stuff
                >
                > there is a good overview article on these kinds of epoxy-granite
                > composites here
                > http://www.machineshopguide.com/pdf/600/Castpolymer.pdf
                >
                > and there is yet another chatter reducing idea over here that
                > might be just the thing for the mini's column
                > http://www.phillyresins.com/products/vibradamp.htm
                >
                > after looking over some of this stuff and doing a few tests I think
                > you could probably get "good'nuff" results with hardware store
                > epoxies and a washed & dried sand/gravel mix
                >
                > HTH
                > Brian
              • teleview102
                I was talking over this type of solution with a machinest co-worker, and he raised the question about whether or not there is the possibility of distorting the
                Message 7 of 25 , May 1, 2002
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                  I was talking over this type of solution with a machinest co-worker,
                  and he raised the question about whether or not there is the
                  possibility of distorting the column my filling it with a material
                  that hardens in place. It seems like a valid concern.

                  Rod B.

                  --- In GrizHFMinimill@y..., Brian Pitt <bfp@e...> wrote:
                  > heres the URL for anocast
                  > http://www.anorad.com/onlineCatalog/anocastComposite.htm
                  >
                  > or check http://www.phillyresins.com for the same kind of stuff
                  >
                  > there is a good overview article on these kinds of epoxy-granite
                  > composites here
                  > http://www.machineshopguide.com/pdf/600/Castpolymer.pdf
                  >
                  > and there is yet another chatter reducing idea over here that
                  > might be just the thing for the mini's column
                  > http://www.phillyresins.com/products/vibradamp.htm
                  >
                  > after looking over some of this stuff and doing a few tests I think
                  > you could probably get "good'nuff" results with hardware store
                  > epoxies and a washed & dried sand/gravel mix
                  >
                  > HTH
                  > Brian
                • mmjarz
                  I agree- As I postulated in earlier post - I think the dampening astion would be maximized if the mass load was somewhat fluid - thus the use of BB Shot
                  Message 8 of 25 , May 2, 2002
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                    I agree- As I postulated in earlier post - I think the dampening
                    astion would be maximized if the mass load was somewhat "fluid" -
                    thus the use of BB Shot with the bottom & (possably ) top of column
                    plugged - I do not intend to fill my collumn all the way to the top
                    either.
                    DRJ

                    --- In GrizHFMinimill@y..., "teleview102" <blueshift@w...> wrote:
                    > I was talking over this type of solution with a machinest co-
                    worker,
                    > and he raised the question about whether or not there is the
                    > possibility of distorting the column my filling it with a material
                    > that hardens in place. It seems like a valid concern.
                    >
                    > Rod B.
                    >
                    > --- In GrizHFMinimill@y..., Brian Pitt <bfp@e...> wrote:
                    > > heres the URL for anocast
                    > > http://www.anorad.com/onlineCatalog/anocastComposite.htm
                    > >
                    > > or check http://www.phillyresins.com for the same kind of stuff
                    > >
                    > > there is a good overview article on these kinds of epoxy-granite
                    > > composites here
                    > > http://www.machineshopguide.com/pdf/600/Castpolymer.pdf
                    > >
                    > > and there is yet another chatter reducing idea over here that
                    > > might be just the thing for the mini's column
                    > > http://www.phillyresins.com/products/vibradamp.htm
                    > >
                    > > after looking over some of this stuff and doing a few tests I
                    think
                    > > you could probably get "good'nuff" results with hardware store
                    > > epoxies and a washed & dried sand/gravel mix
                    > >
                    > > HTH
                    > > Brian
                  • j_t_wright
                    Folks, Perhaps a silly question, where does one find lead shot or bb shot on-line or in likely local establishments? Was looking for some for exactly this
                    Message 9 of 25 , May 2, 2002
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                      Folks,
                      Perhaps a silly question, where does one find
                      lead shot or bb shot on-line or in likely local establishments?
                      Was looking for some for exactly this purpose and did
                      not seem to ken the right places to find it... :-(

                      I did find shot gun quality shot, but it was
                      just a *tad* expensive.

                      Any suggestions?

                      Thanks!

                      Jim

                      --- In GrizHFMinimill@y..., "mmjarz" <mmjarz@y...> wrote:
                      > I agree- As I postulated in earlier post - I think the dampening
                      > astion would be maximized if the mass load was somewhat "fluid" -
                      > thus the use of BB Shot with the bottom & (possably ) top of column
                      > plugged - I do not intend to fill my collumn all the way to the top
                      > either.
                      > DRJ
                      >
                    • Rick Kruger
                      Don t know that you ll find lead shot other than for shotguns. What is a tad expensive ? I just bought a 25 lb. bag for $17 at a gun shop. Had to call
                      Message 10 of 25 , May 2, 2002
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                        Don't know that you'll find lead shot other than for shotguns. What is "a
                        tad expensive"? I just bought a 25 lb. bag for $17 at a gun shop. Had to
                        call several to find it. Some said they couldn't get it, but I knew better
                        and kept calling.

                        Rick K.
                        Portland, OR

                        At 04:28 AM 5/3/02 +0000, you wrote:
                        >Folks,
                        > Perhaps a silly question, where does one find
                        >lead shot or bb shot on-line or in likely local establishments?
                        >Was looking for some for exactly this purpose and did
                        >not seem to ken the right places to find it... :-(
                        >
                        > I did find shot gun quality shot, but it was
                        >just a *tad* expensive.
                        >
                        > Any suggestions?
                        >
                        > Thanks!
                        >
                        > Jim
                        >
                        >--- In GrizHFMinimill@y..., "mmjarz" <mmjarz@y...> wrote:
                        > > I agree- As I postulated in earlier post - I think the dampening
                        > > astion would be maximized if the mass load was somewhat "fluid" -
                        > > thus the use of BB Shot with the bottom & (possably ) top of column
                        > > plugged - I do not intend to fill my collumn all the way to the top
                        > > either.
                        > > DRJ
                        > >
                      • j_t_wright
                        Rick, Thanks! I will call around local gun shops. $17/25 lbs. is just fine. Jim ... What is a ... Had to ... knew better
                        Message 11 of 25 , May 2, 2002
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                          Rick,

                          Thanks! I will call around local gun shops.
                          $17/25 lbs. is just fine.

                          Jim
                          --- In GrizHFMinimill@y..., Rick Kruger <krugerr@e...> wrote:
                          > Don't know that you'll find lead shot other than for shotguns.
                          What is "a
                          > tad expensive"? I just bought a 25 lb. bag for $17 at a gun shop.
                          Had to
                          > call several to find it. Some said they couldn't get it, but I
                          knew better
                          > and kept calling.
                        • Barry
                          ... so you think I oughta stop opening all these shotgun shells and just buy a bag of lead?... Doh! ;-/ Seriously, anyone found a good way to cap off the
                          Message 12 of 25 , May 3, 2002
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                            ... so you think I oughta stop opening all these shotgun shells and just buy
                            a bag of lead?... Doh!
                            ;-/

                            Seriously, anyone found a good way to cap off the bottom to keep the shot in
                            there? I was going to use a thick piece of aluminum that fits in the
                            opening and bolt it in place.
                            Barry
                            _____ B a r r y ' s F a b S h o p _____
                            http://members.cox.net/eagletwo/lathe.htm
                            ----- Original Message -----
                            --
                            Subject: [GrizHFMinimill] Re: Column bracing-anocast
                            --
                            > What is "a tad expensive"? I just bought a 25 lb. bag for $17 at a gun
                            shop.
                            > Had to call several to find it. Some said they couldn't get it, but I
                            knew better
                            > and kept calling.
                          • David Audette
                            Has anyone given thought to melting down old automobile wheel weights ? They re dirt cheap ( free at the 2 shops I stopped in at locally ) as they aren t
                            Message 13 of 25 , May 3, 2002
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                              Has anyone given thought to melting down old automobile wheel weights ?
                              They're dirt cheap ( free at the 2 shops I stopped in at locally ) as they
                              aren't reused, tire shops have buckets of them.

                              Another thought, I have an uncle who's a dentist and pays someone to come in
                              every month and haul out the small slips of lead that are used for *every*
                              dental X-ray. He PAYS somebody to come take his lead away.

                              Those are just 2 sources of free lead that I know of. Don't forget that in
                              the world of business lead is a HAZMAT and they pay people to remove it.

                              Depending upon how much your time is worth to you a few phone calls my be
                              worth the effort.

                              Personally, I have about 150lbs of old diving weights I was thinking of
                              using but they foul the bandsaw blades so badly that I don't want to bother
                              cutting them. I'll probably use the wheel weights and skim off all the dross
                              ( the advantage in the dental lead is that it's super clean but the wheel
                              weights are understandably filthy )

                              Just a few thoughts.

                              Dave
                              www.broncosaurus.net

                              ----- Original Message -----
                              From: "Barry" <eagletwo@...>
                              To: <GrizHFMinimill@yahoogroups.com>
                              Sent: Friday, May 03, 2002 8:45 AM
                              Subject: Re: [GrizHFMinimill] Re: Column bracing-anocast


                              > ... so you think I oughta stop opening all these shotgun shells and just
                              buy
                              > a bag of lead?... Doh!
                              > ;-/
                              >
                              > Seriously, anyone found a good way to cap off the bottom to keep the shot
                              in
                              > there? I was going to use a thick piece of aluminum that fits in the
                              > opening and bolt it in place.
                              > Barry
                              > _____ B a r r y ' s F a b S h o p _____
                              > http://members.cox.net/eagletwo/lathe.htm
                              > ----- Original Message -----
                              > --
                              > Subject: [GrizHFMinimill] Re: Column bracing-anocast
                              > --
                              > > What is "a tad expensive"? I just bought a 25 lb. bag for $17 at a gun
                              > shop.
                              > > Had to call several to find it. Some said they couldn't get it, but I
                              > knew better
                              > > and kept calling.
                              >
                              >
                              >
                              >
                              > To unsubscribe from this group, send an email to:
                              > GrizHFMinimill-unsubscribe@yahoogroups.com
                              >
                              >
                              >
                              > Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
                              >
                              >
                            • Rick Kruger
                              Might be worth it if you can make shot or very small parts from it. I think a major part of the value of the shot is that it is fluid, not solid, so it
                              Message 14 of 25 , May 3, 2002
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                                Might be worth it if you can make shot or very small parts from it. I
                                think a major part of the value of the shot is that it is fluid, not solid,
                                so it absorbs the movement rather than transmit it. My thought it is
                                casting the led into the center would not be nearly as good as loose
                                shot. Don't know tho, haven't compared them in a real test.

                                Rick K.
                                Portland, OR

                                At 09:01 AM 5/3/02 -0400, you wrote:
                                >Has anyone given thought to melting down old automobile wheel weights ?
                                >They're dirt cheap ( free at the 2 shops I stopped in at locally ) as they
                                >aren't reused, tire shops have buckets of them.
                                >
                                >Another thought, I have an uncle who's a dentist and pays someone to come in
                                >every month and haul out the small slips of lead that are used for *every*
                                >dental X-ray. He PAYS somebody to come take his lead away.
                                >
                                >Those are just 2 sources of free lead that I know of. Don't forget that in
                                >the world of business lead is a HAZMAT and they pay people to remove it.
                                >
                                >Depending upon how much your time is worth to you a few phone calls my be
                                >worth the effort.
                                >
                                >Personally, I have about 150lbs of old diving weights I was thinking of
                                >using but they foul the bandsaw blades so badly that I don't want to bother
                                >cutting them. I'll probably use the wheel weights and skim off all the dross
                                >( the advantage in the dental lead is that it's super clean but the wheel
                                >weights are understandably filthy )
                                >
                                >Just a few thoughts.
                                >
                                >Dave
                                >www.broncosaurus.net
                                >
                                >----- Original Message -----
                                >From: "Barry" <eagletwo@...>
                                >To: <GrizHFMinimill@yahoogroups.com>
                                >Sent: Friday, May 03, 2002 8:45 AM
                                >Subject: Re: [GrizHFMinimill] Re: Column bracing-anocast
                                >
                                >
                                > > ... so you think I oughta stop opening all these shotgun shells and just
                                >buy
                                > > a bag of lead?... Doh!
                                > > ;-/
                                > >
                                > > Seriously, anyone found a good way to cap off the bottom to keep the shot
                                >in
                                > > there? I was going to use a thick piece of aluminum that fits in the
                                > > opening and bolt it in place.
                                > > Barry
                                > > _____ B a r r y ' s F a b S h o p _____
                                > > http://members.cox.net/eagletwo/lathe.htm
                                > > ----- Original Message -----
                                > > --
                                > > Subject: [GrizHFMinimill] Re: Column bracing-anocast
                                > > --
                                > > > What is "a tad expensive"? I just bought a 25 lb. bag for $17 at a gun
                                > > shop.
                                > > > Had to call several to find it. Some said they couldn't get it, but I
                                > > knew better
                                > > > and kept calling.
                              • Rick Kruger
                                Not there yet, but I was going to do similar, but use flat head screws so nothing protruded. One mine, with the angle plate on the rear, both the front and
                                Message 15 of 25 , May 3, 2002
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                                  Not there yet, but I was going to do similar, but use flat head screws so
                                  nothing protruded. One mine, with the angle plate on the rear, both the
                                  front and rear surfaces are clamped against, & so need to be flush.

                                  Rick K.
                                  Portland, OR

                                  At 07:45 AM 5/3/02 -0500, you wrote:
                                  >... so you think I oughta stop opening all these shotgun shells and just buy
                                  >a bag of lead?... Doh!
                                  >;-/
                                  >
                                  >Seriously, anyone found a good way to cap off the bottom to keep the shot in
                                  >there? I was going to use a thick piece of aluminum that fits in the
                                  >opening and bolt it in place.
                                  >Barry
                                  >_____ B a r r y ' s F a b S h o p _____
                                  >http://members.cox.net/eagletwo/lathe.htm
                                  >----- Original Message -----
                                  >--
                                  >Subject: [GrizHFMinimill] Re: Column bracing-anocast
                                  >--
                                  > > What is "a tad expensive"? I just bought a 25 lb. bag for $17 at a gun
                                  >shop.
                                  > > Had to call several to find it. Some said they couldn't get it, but I
                                  >knew better
                                  > > and kept calling.
                                  >
                                  >
                                  >
                                  >
                                  >To unsubscribe from this group, send an email to:
                                  >GrizHFMinimill-unsubscribe@yahoogroups.com
                                  >
                                  >
                                  >
                                  >Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
                                  >
                                • mmjarz
                                  I saw a post in this or LATHES group about using silicone ???? I m planning to find a plastic pipe that the pivot bolt will fit thru & slide it up inside the
                                  Message 16 of 25 , May 3, 2002
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                                    I saw a post in this or LATHES group about using silicone ????
                                    I'm planning to find a plastic pipe that the pivot bolt will fit thru
                                    & slide it up inside the Column - I also have an old rubber Hocky
                                    Puck laying on my bench - thot I'd check out the dimensions of the
                                    puck vs column hole & trim & silicone it in there - then pour in the
                                    shot.....
                                    Dave J

                                    --- In GrizHFMinimill@y..., Rick Kruger <krugerr@e...> wrote:
                                    > Not there yet, but I was going to do similar, but use flat head
                                    screws so
                                    > nothing protruded. One mine, with the angle plate on the rear,
                                    both the
                                    > front and rear surfaces are clamped against, & so need to be flush.
                                    >
                                    > Rick K.
                                    -------------snip-----------------
                                    > >Seriously, anyone found a good way to cap off the bottom to keep
                                    the shot in
                                    > >there? I was going to use a thick piece of aluminum that fits in
                                    the
                                    > >opening and bolt it in place.
                                    > >Barry

                                    ---------------snip--------------
                                    > > > What is "a tad expensive"? I just bought a 25 lb. bag for $17
                                    at a gun shop.
                                    > > > Had to call several to find it.
                                  • Jim E.
                                    I think I d rather handle filthy wheel weights than dental lead. Tetanus I ve been immunized for. What could be on the dental lead I haven t been. Graciously,
                                    Message 17 of 25 , May 3, 2002
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                                      I think I'd rather handle filthy wheel weights than dental lead.
                                      Tetanus I've been immunized for. What could be on the dental lead I
                                      haven't been.

                                      Graciously,
                                      Jim
                                      Lakewood, CA
                                      All Hail Rube Goldberg!

                                      David Audette wrote:
                                      <snip>
                                      > Another thought, I have an uncle who's a dentist and pays someone to come in
                                      > every month and haul out the small slips of lead that are used for *every*
                                      > dental X-ray. He PAYS somebody to come take his lead away.
                                      <snip>
                                      > ( the advantage in the dental lead is that it's super clean but the wheel
                                      > weights are understandably filthy )
                                      >
                                      > Just a few thoughts.
                                      >
                                      > Dave
                                      > www.broncosaurus.net
                                      >
                                    • David Audette
                                      Jim, The lead slips are completely covered in several layers of plastic and have their own jackets. Think about it for a moment, lead is a known toxin. Forget
                                      Message 18 of 25 , May 3, 2002
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                                        Jim,

                                        The lead slips are completely covered in several layers of plastic and
                                        have their own jackets.

                                        Think about it for a moment, lead is a known toxin. Forget about the
                                        dentists & FDA for a minute, do you think the American Bar Association &
                                        their membership would allow dental practices that put raw lead into peoples
                                        mouthes ? Next time you go take a look at the gear he uses. We've all had
                                        dental X-rays, do you ever remember a piece of lead being stuck in your
                                        mouth ?

                                        Dave
                                        www.mini-lathe.com

                                        ----- Original Message -----
                                        From: "Jim E." <jim0000@...>
                                        To: <GrizHFMinimill@yahoogroups.com>
                                        Sent: Friday, May 03, 2002 12:55 PM
                                        Subject: Re: [GrizHFMinimill] Re: Column bracing-anocast


                                        > I think I'd rather handle filthy wheel weights than dental lead.
                                        > Tetanus I've been immunized for. What could be on the dental lead I
                                        > haven't been.
                                        >
                                        > Graciously,
                                        > Jim
                                        > Lakewood, CA
                                        > All Hail Rube Goldberg!
                                        >
                                        > David Audette wrote:
                                        > <snip>
                                        > > Another thought, I have an uncle who's a dentist and pays someone to
                                        come in
                                        > > every month and haul out the small slips of lead that are used for
                                        *every*
                                        > > dental X-ray. He PAYS somebody to come take his lead away.
                                        > <snip>
                                        > > ( the advantage in the dental lead is that it's super clean but the
                                        wheel
                                        > > weights are understandably filthy )
                                        > >
                                        > > Just a few thoughts.
                                        > >
                                        > > Dave
                                        > > www.broncosaurus.net
                                        > >
                                        >
                                        >
                                        > To unsubscribe from this group, send an email to:
                                        > GrizHFMinimill-unsubscribe@yahoogroups.com
                                        >
                                        >
                                        >
                                        > Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
                                        >
                                        >
                                        >
                                      • brucegriffing
                                        ... it. I ... not solid, ... is ... loose ... The value from filling the column can come any of several possibilities. First and most obvious is increasing
                                        Message 19 of 25 , May 3, 2002
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                                          --- In GrizHFMinimill@y..., Rick Kruger <krugerr@e...> wrote:
                                          > Might be worth it if you can make shot or very small parts from
                                          it. I
                                          > think a major part of the value of the shot is that it is fluid,
                                          not solid,
                                          > so it absorbs the movement rather than transmit it. My thought it
                                          is
                                          > casting the led into the center would not be nearly as good as
                                          loose
                                          > shot. Don't know tho, haven't compared them in a real test.
                                          >
                                          > Rick K.
                                          > Portland, OR

                                          The value from filling the column can come any of several
                                          possibilities. First and most obvious is increasing the mass. The
                                          effect of increased mass will be to lower the natural vibrational
                                          modes of the machine. It is very hard to drive vibration at
                                          frequencies above the natural resonance(s), so reducing that
                                          frequency is a generally a benefit. It really depends on the
                                          details. It is also true that loose material will more readily
                                          absorb energy at some frequencies. But sometimes it is beneficial
                                          to make the system parts stiffer. This could be accomplished by
                                          filling the column with concrete. It would also add mass, but might
                                          work very well in this case. Accomodation for the bolt hole and a
                                          bottom cover would obviously be critical. It would not be a good
                                          choice for an air spring machine either. Something to think about.


                                          Bruce Griffing
                                        • Ron Yost
                                          ... It is also true that loose material will more readily ... How about concrete with a couple of rebar rods incased? Similar to a highway ramp. Sounds
                                          Message 20 of 25 , May 3, 2002
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                                            >snip<

                                            It is also true that loose material will more readily
                                            >absorb energy at some frequencies. But sometimes it is beneficial
                                            >to make the system parts stiffer. This could be accomplished by
                                            >filling the column with concrete. It would also add mass, but might
                                            >work very well in this case. Accomodation for the bolt hole and a
                                            >bottom cover would obviously be critical. It would not be a good
                                            >choice for an air spring machine either. Something to think about.
                                            >
                                            >
                                            >Bruce Griffing

                                            How about concrete with a couple of rebar rods incased? Similar to a
                                            highway ramp. Sounds silly, I know, but ...

                                            Or .. for vibration damping .. vicsous fluid (heavy oil). Maybe oil
                                            -and- shot?? Would that accomplish both objectives??

                                            The resonances needing damping are low frequency, right? Some of that
                                            comes from the cheezy motors on these machines, tho any DC motor
                                            will resonate at low speed. These little motors are worse than most,
                                            in my experience.

                                            Ron Yost
                                          • brucegriffing
                                            ... that ... Ron- Resonance is a property of the structure and depends on stiffness and mass. The motor, if out of balance, will contribute a driving
                                            Message 21 of 25 , May 5, 2002
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                                              > The resonances needing damping are low frequency, right? Some of
                                              that
                                              > comes from the cheezy motors on these machines, tho any DC motor
                                              > will resonate at low speed. These little motors are worse than most,
                                              > in my experience.
                                              >
                                              > Ron Yost

                                              Ron-
                                              Resonance is a property of the structure and depends on stiffness
                                              and mass. The motor, if out of balance, will contribute a driving
                                              vibration at a frequency related to the speed. How that driving
                                              vibration couples to the resonances of the structure is the key
                                              question. You can get a good result with a smooth motor or with a
                                              structure whose maximum resonant frequency is well below that of the
                                              driving frequency of the motor. Structures with greater stiffness
                                              require more vibration energy to produce the same vibrational
                                              displacement - so stiffness helps in that sense. But greater
                                              stiffness drives up the structure's resonant frequency. That can be
                                              bad. In carefully done machine designs, these things are all
                                              calculated in advance and measured. The optimal design will minimize
                                              vibration.
                                            • Barry Young
                                              Hi Jim: They are talking about shot for shotshells. You are exactly on track. Barry Young ... __________________________________________________ Do You Yahoo!?
                                              Message 22 of 25 , May 5, 2002
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                                                Hi Jim:

                                                They are talking about shot for shotshells. You are
                                                exactly on track.

                                                Barry Young


                                                --- j_t_wright <jtw@...> wrote:
                                                > Folks,
                                                > Perhaps a silly question, where does one find
                                                > lead shot or bb shot on-line or in likely local
                                                > establishments?
                                                > Was looking for some for exactly this purpose and
                                                > did
                                                > not seem to ken the right places to find it... :-(
                                                >
                                                > I did find shot gun quality shot, but it was
                                                > just a *tad* expensive.
                                                >
                                                > Any suggestions?
                                                >
                                                > Thanks!
                                                >
                                                > Jim
                                                >
                                                > --- In GrizHFMinimill@y..., "mmjarz" <mmjarz@y...>
                                                > wrote:
                                                > > I agree- As I postulated in earlier post - I
                                                > think the dampening
                                                > > astion would be maximized if the mass load was
                                                > somewhat "fluid" -
                                                > > thus the use of BB Shot with the bottom &
                                                > (possably ) top of column
                                                > > plugged - I do not intend to fill my collumn all
                                                > the way to the top
                                                > > either.
                                                > > DRJ
                                                > >
                                                >
                                                >
                                                >
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                                              • catboat15@aol.com
                                                In a message dated 5/2/2002 9:53:25 PM Pacific Standard Time, ... Lead shot is difficult to find in some areas since lead shot has been outlawed for duck and
                                                Message 23 of 25 , May 18, 2002
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                                                  In a message dated 5/2/2002 9:53:25 PM Pacific Standard Time, krugerr@... writes:


                                                  I just bought a 25 lb. bag for $17 at a gun shop.


                                                  Lead shot is difficult to find in some areas since lead shot has been outlawed for duck and wild bird hunting since the birds ingest lead shot and get poisoned.  Try places that cater to skeet shooters. 

                                                  John Meacham
                                                  3-1/2 gauge, LBSC Virginia
                                                  Plus many in process or in thoughts
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