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Grinding comments

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  • David G. LeVine
    One big disadvantage of grinding is that the spent abrasive gets on the ways. This is BAD as it wears the ways. Two obvious options are to put plastic film on
    Message 1 of 18 , Nov 23, 2012
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      One big disadvantage of grinding is that the spent abrasive gets on the ways.  This is BAD as it wears the ways.

      Two obvious options are to put plastic film on the ways, then cover that with wet terry or paper towels.  The abrasive sticks to the wet toweling and protects the ways.  This technique has also been recommended for cast iron.

      Another approach is an "air knife", a thin sheet of high speed, high pressure air.  This has many issues, it needs a good air supply, it blows the spent abrasive and chips out at high speed, etc.  For these reasons, I have only seen this used on fully enclosed CNC machines with flood coolant, which id blown off the ways so it can be filtered.  There is still wear, just not as much.

      Yes, wipers (often felt) and scrapers (often plastic) do help, but one abrasive particle embedded in the wiper or scraper and the wear begins.

      Comments?

      Dave  8{)
      --

      "The first method for estimating the intelligence of a ruler is to look at the men he has around him."
      Niccolo Machiavelli

      NOTE TO ALL:

      When forwarding emails, please use only "Blind Carbon Copy" or "Bcc" for all recipients. Please "delete" or "highlight & cut" any forwarding history which includes my email address! It is a courtesy to me and others who may not wish to have their email addresses sent all over the world! Erasing the history helps prevent Spammers from mining addresses and viruses from being propagated.


      THANK YOU!
    • Chris Tofu
      C: Wipers should not be seen as a remedy for grinding grit/dust. The ways do need to be protected, but _especially_ the spindle bearings. I m not sure what
      Message 2 of 18 , Nov 23, 2012
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        C: Wipers should not be seen as a remedy for grinding grit/dust. The ways do need to be protected, but _especially_ the spindle bearings. I'm not sure what this is in response to exactly, but as it seems we're talking about toolpost grinding, plastic sheet w/a hole punched for the spindle end, draped over the back of the headstock and the ways is good, with coolant, preferably delivered w/some pressure, blown over the workpiece at the point where the grinding wheel hits the work piece. Additional "shields" of some sort to prevent entry of grinding dust to the bearings would also be desirable, cardboard maybe or plastic. Chips from turning and especially grinding residue can usually be found in 3 places - everywhere, Everywhere, and especially EVERYWHERE. Sometimes even eVeRyWhErE. So count on it and prepare accordingly.
      • Jeffrey Lasley
        Hello everyone, Had anyone thought of vacuum cleaner with a big catch opening on the end of the hose close to the works being done? I knows it being used for
        Message 3 of 18 , Nov 23, 2012
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          Hello everyone, Had anyone thought of vacuum cleaner with a big catch opening on the end of the hose close to the works being done? I knows it being used for woodworking to collect wood chips and dusts. Just a thought as maybe a some sort of a square bowl under and back to the hose pulling these spent abrasives away off the ways.  Just an idea I had in my mind, Jeffrey L.

          From: David G. LeVine <dlevine@...>
          To: multimachine@yahoogroups.com
          Sent: Friday, November 23, 2012 8:50 PM
          Subject: [multimachine] Grinding comments
           
          One big disadvantage of grinding is that the spent abrasive gets on the ways.  This is BAD as it wears the ways.

          Two obvious options are to put plastic film on the ways, then cover that with wet terry or paper towels.  The abrasive sticks to the wet toweling and protects the ways.  This technique has also been recommended for cast iron.

          Another approach is an "air knife", a thin sheet of high speed, high pressure air.  This has many issues, it needs a good air supply, it blows the spent abrasive and chips out at high speed, etc.  For these reasons, I have only seen this used on fully enclosed CNC machines with flood coolant, which id blown off the ways so it can be filtered.  There is still wear, just not as much.

          Yes, wipers (often felt) and scrapers (often plastic) do help, but one abrasive particle embedded in the wiper or scraper and the wear begins.

          Comments?

          Dave  8{)
          -- "The first method for estimating the intelligence of a ruler is to look at the men he has around him." Niccolo Machiavelli
          NOTE TO ALL:

          When forwarding emails, please use only "Blind Carbon Copy" or "Bcc" for all recipients. Please "delete" or "highlight & cut" any forwarding history which includes my email address! It is a courtesy to me and others who may not wish to have their email addresses sent all over the world! Erasing the history helps prevent Spammers from mining addresses and viruses from being propagated.
          THANK YOU!
        • Chris Tofu
          What about rare earth magnets and coolant? How long will a shop vac work with all that fine grit. Even with a filter, perhaps there are better filters for the
          Message 4 of 18 , Nov 24, 2012
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            What about rare earth magnets and coolant? How long will a shop vac work with all that fine grit. Even with a filter, perhaps there are better filters for the job?
          • Pat Delany
            The concrete lathe was designed (in my mind) to be used as a grinder platform. I had these random points in mind: It can cut training time by a huge amount. It
            Message 5 of 18 , Nov 24, 2012
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              The concrete lathe was designed (in my mind) to be used as a grinder platform.

              I had these random points in mind:
              It can cut training time by a huge amount. It is easy to train someone to turn slightly oversize and with a rough finish and then to grind to a good fit and finish
              It allows the use of un-machinable(transmission parts?) and welded steel.
              Damage from grit is not fatal, the ways can be rotated to unworn areas and as a last resort, the carriage could be replaced.
              The ways should be protected by a flexible cover attached between the headstock and the carriage,

              Pat


              From: Jeffrey Lasley <whtblazer2@...>
              To: "multimachine@yahoogroups.com" <multimachine@yahoogroups.com>
              Sent: Friday, November 23, 2012 10:46 PM
              Subject: Re: [multimachine] Grinding comments

               
              Hello everyone, Had anyone thought of vacuum cleaner with a big catch opening on the end of the hose close to the works being done? I knows it being used for woodworking to collect wood chips and dusts. Just a thought as maybe a some sort of a square bowl under and back to the hose pulling these spent abrasives away off the ways.  Just an idea I had in my mind, Jeffrey L.

              From: David G. LeVine <dlevine@...>
              To: multimachine@yahoogroups.com
              Sent: Friday, November 23, 2012 8:50 PM
              Subject: [multimachine] Grinding comments
               
              One big disadvantage of grinding is that the spent abrasive gets on the ways.  This is BAD as it wears the ways.

              Two obvious options are to put plastic film on the ways, then cover that with wet terry or paper towels.  The abrasive sticks to the wet toweling and protects the ways.  This technique has also been recommended for cast iron.

              Another approach is an "air knife", a thin sheet of high speed, high pressure air.  This has many issues, it needs a good air supply, it blows the spent abrasive and chips out at high speed, etc.  For these reasons, I have only seen this used on fully enclosed CNC machines with flood coolant, which id blown off the ways so it can be filtered.  There is still wear, just not as much.

              Yes, wipers (often felt) and scrapers (often plastic) do help, but one abrasive particle embedded in the wiper or scraper and the wear begins.

              Comments?

              Dave  8{)
              -- "The first method for estimating the intelligence of a ruler is to look at the men he has around him." Niccolo Machiavelli
              NOTE TO ALL:

              When forwarding emails, please use only "Blind Carbon Copy" or "Bcc" for all recipients. Please "delete" or "highlight & cut" any forwarding history which includes my email address! It is a courtesy to me and others who may not wish to have their email addresses sent all over the world! Erasing the history helps prevent Spammers from mining addresses and viruses from being propagated.
              THANK YOU!


            • David G. LeVine
              ... Your understanding is sufficient and complete. This was a discussion of toolpost grinding. And you are slightly wrong, the grit gets everywhere EXCEPT
              Message 6 of 18 , Nov 24, 2012
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                On 11/23/2012 11:01 PM, Chris Tofu wrote:
                C: Wipers should not be seen as a remedy for grinding grit/dust. The ways do need to be protected, but _especially_ the spindle bearings. I'm not sure what this is in response to exactly, but as it seems we're talking about toolpost grinding, plastic sheet w/a hole punched for the spindle end, draped over the back of the headstock and the ways is good, with coolant, preferably delivered w/some pressure, blown over the workpiece at the point where the grinding wheel hits the work piece. Additional "shields" of some sort to prevent entry of grinding dust to the bearings would also be desirable, cardboard maybe or plastic. Chips from turning and especially grinding residue can usually be found in 3 places - everywhere, Everywhere, and especially EVERYWHERE. Sometimes even eVeRyWhErE. So count on it and prepare accordingly.

                Your understanding is sufficient and complete.  This was a discussion of toolpost grinding.  And you are slightly wrong, the grit gets everywhere EXCEPT where you want it.

                Dave  8{)

                --

                "The first method for estimating the intelligence of a ruler is to look at the men he has around him."
                Niccolo Machiavelli

                NOTE TO ALL:

                When forwarding emails, please use only "Blind Carbon Copy" or "Bcc" for all recipients. Please "delete" or "highlight & cut" any forwarding history which includes my email address! It is a courtesy to me and others who may not wish to have their email addresses sent all over the world! Erasing the history helps prevent Spammers from mining addresses and viruses from being propagated.


                THANK YOU!
              • David G. LeVine
                ... Good one, except the wood chips are orders of magnitude less dense than grinding grit. The size is much smaller, so the grit is less affected by airflow.
                Message 7 of 18 , Nov 24, 2012
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                  On 11/23/2012 11:46 PM, Jeffrey Lasley wrote:
                  Hello everyone, Had anyone thought of vacuum cleaner with a big catch opening on the end of the hose close to the works being done? I knows it being used for woodworking to collect wood chips and dusts. Just a thought as maybe a some sort of a square bowl under and back to the hose pulling these spent abrasives away off the ways.  Just an idea I had in my mind, Jeffrey L.

                  Good one, except the wood chips are orders of magnitude less dense than grinding grit.  The size is much smaller, so the grit is less affected by airflow.

                  Dave  8{)

                  --

                  "The first method for estimating the intelligence of a ruler is to look at the men he has around him."
                  Niccolo Machiavelli

                  NOTE TO ALL:

                  When forwarding emails, please use only "Blind Carbon Copy" or "Bcc" for all recipients. Please "delete" or "highlight & cut" any forwarding history which includes my email address! It is a courtesy to me and others who may not wish to have their email addresses sent all over the world! Erasing the history helps prevent Spammers from mining addresses and viruses from being propagated.


                  THANK YOU!
                • David G. LeVine
                  ... Grinding grit is non-magnetic. Coolant works well, but needs a fully enclosed machine. Dave 8{) -- / The first method for estimating the intelligence of a
                  Message 8 of 18 , Nov 24, 2012
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                    On 11/24/2012 01:18 PM, Chris Tofu wrote:
                    What about rare earth magnets and coolant? How long will a shop vac work with all that fine grit. Even with a filter, perhaps there are better filters for the job?

                    Grinding grit is non-magnetic.

                    Coolant works well, but needs a fully enclosed machine.

                    Dave  8{)

                    --

                    "The first method for estimating the intelligence of a ruler is to look at the men he has around him."
                    Niccolo Machiavelli

                    NOTE TO ALL:

                    When forwarding emails, please use only "Blind Carbon Copy" or "Bcc" for all recipients. Please "delete" or "highlight & cut" any forwarding history which includes my email address! It is a courtesy to me and others who may not wish to have their email addresses sent all over the world! Erasing the history helps prevent Spammers from mining addresses and viruses from being propagated.


                    THANK YOU!
                  • David G. LeVine
                    ... Pat, I am not saying don t do it! , just be aware of the implications. If the spindle lasts only a few dozen hours, it will doom things. Dave 8{) --
                    Message 9 of 18 , Nov 24, 2012
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                      On 11/24/2012 01:28 PM, Pat Delany wrote:
                      The concrete lathe was designed (in my mind) to be used as a grinder platform.

                      I had these random points in mind:
                      It can cut training time by a huge amount. It is easy to train someone to turn slightly oversize and with a rough finish and then to grind to a good fit and finish
                      It allows the use of un-machinable(transmission parts?) and welded steel.
                      Damage from grit is not fatal, the ways can be rotated to unworn areas and as a last resort, the carriage could be replaced.
                      The ways should be protected by a flexible cover attached between the headstock and the carriage,

                      Pat

                      Pat,

                      I am not saying "don't do it!", just "be aware of the implications."  If the spindle lasts only a few dozen hours, it will doom things.

                      Dave  8{)

                      --

                      "The first method for estimating the intelligence of a ruler is to look at the men he has around him."
                      Niccolo Machiavelli

                      NOTE TO ALL:

                      When forwarding emails, please use only "Blind Carbon Copy" or "Bcc" for all recipients. Please "delete" or "highlight & cut" any forwarding history which includes my email address! It is a courtesy to me and others who may not wish to have their email addresses sent all over the world! Erasing the history helps prevent Spammers from mining addresses and viruses from being propagated.


                      THANK YOU!
                    • chad jensen
                      I ran an od grinder in a machine shop for a while and i never remember any issues with grit on the ways. But that was probably because the grinder used a flood
                      Message 10 of 18 , Nov 25, 2012
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                        I ran an od grinder in a machine shop for a while and i never remember any issues with grit on the ways. But that was probably because the grinder used a flood coolant.
                        Chad

                        On Nov 24, 2012 11:18 AM, "Chris Tofu" <rampaginggreenhulk@...> wrote:
                         


                        What about rare earth magnets and coolant? How long will a shop vac work with all that fine grit. Even with a filter, perhaps there are better filters for the job?

                      • David G. LeVine
                        ... Yup, you got it exactly. Flood coolant eliminates dust most of the time. Particles well below a mm tend to stay in the fluid and be filtered out on each
                        Message 11 of 18 , Nov 25, 2012
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                          On 11/25/2012 08:58 AM, chad jensen wrote:
                          I ran an od grinder in a machine shop for a while and i never remember any issues with grit on the ways. But that was probably because the grinder used a flood coolant.
                          Chad

                          Yup, you got it exactly.  Flood coolant eliminates dust most of the time.  Particles well below a mm tend to stay in the fluid and be filtered out on each pass.  Stuff below 10 microns may not be caught, but it is much less damaging.  It results in wear, but it is slow.

                          Stuff below 1/2 micron is probably not a problem for the MM...

                          Dave  8{)

                          --

                          "The first method for estimating the intelligence of a ruler is to look at the men he has around him."
                          Niccolo Machiavelli

                          NOTE TO ALL:

                          When forwarding emails, please use only "Blind Carbon Copy" or "Bcc" for all recipients. Please "delete" or "highlight & cut" any forwarding history which includes my email address! It is a courtesy to me and others who may not wish to have their email addresses sent all over the world! Erasing the history helps prevent Spammers from mining addresses and viruses from being propagated.


                          THANK YOU!
                        • Pat Delany
                          Could you use coolant around an angle grinder? I had an extension shaft for an angle grinder  made by an expert machinist but the runout was terrible. Pat
                          Message 12 of 18 , Nov 25, 2012
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                            Could you use coolant around an angle grinder? I had an extension shaft for an angle grinder  made by an expert machinist but the runout was terrible.

                            Pat


                            From: David G. LeVine <dlevine@...>
                            To: multimachine@yahoogroups.com
                            Sent: Sunday, November 25, 2012 2:43 PM
                            Subject: Re: [multimachine] Grinding comments

                             
                            On 11/25/2012 08:58 AM, chad jensen wrote:
                            I ran an od grinder in a machine shop for a while and i never remember any issues with grit on the ways. But that was probably because the grinder used a flood coolant.
                            Chad

                            Yup, you got it exactly.  Flood coolant eliminates dust most of the time.  Particles well below a mm tend to stay in the fluid and be filtered out on each pass.  Stuff below 10 microns may not be caught, but it is much less damaging.  It results in wear, but it is slow.

                            Stuff below 1/2 micron is probably not a problem for the MM...

                            Dave  8{)

                            --

                            "The first method for estimating the intelligence of a ruler is to look at the men he has around him."
                            Niccolo Machiavelli

                            NOTE TO ALL:

                            When forwarding emails, please use only "Blind Carbon Copy" or "Bcc" for all recipients. Please "delete" or "highlight & cut" any forwarding history which includes my email address! It is a courtesy to me and others who may not wish to have their email addresses sent all over the world! Erasing the history helps prevent Spammers from mining addresses and viruses from being propagated.


                            THANK YOU!


                          • David G. LeVine
                            ... Yes, but... It is not a good idea with an electric angle grinder unless you have a non-conductive coolant. Chips tend to live in the coolant and tend to
                            Message 13 of 18 , Nov 25, 2012
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                              On 11/25/2012 04:10 PM, Pat Delany wrote:


                              Could you use coolant around an angle grinder? I had an extension shaft for an angle grinder  made by an expert machinist but the runout was terrible.

                              Pat

                              Yes, but...  It is not a good idea with an electric angle grinder unless you have a non-conductive coolant.  Chips tend to live in the coolant and tend to do bad things in electrical equipment.  Pneumatic angle grinders, however, are not a bad choice.  Consider that any tool in flood coolant will splash it everywhere except where you want it to go.

                              So, if you are ready to fully enclose the machine and add all the goodies flood coolant needs, it will work, but only expect it to work if you do so.

                              If you fully guard the ways and spindle, you can dry grind, but that is a pretty ambitious project, well beyond an MM.

                              Dave  8{)

                              --

                              "The first method for estimating the intelligence of a ruler is to look at the men he has around him."
                              Niccolo Machiavelli

                              NOTE TO ALL:

                              When forwarding emails, please use only "Blind Carbon Copy" or "Bcc" for all recipients. Please "delete" or "highlight & cut" any forwarding history which includes my email address! It is a courtesy to me and others who may not wish to have their email addresses sent all over the world! Erasing the history helps prevent Spammers from mining addresses and viruses from being propagated.


                              THANK YOU!
                            • Nick Andrews
                              How about a pneumatic die grinder like Humpty Fright sells cheap? ... -- Nick A You know what I wish? I wish that all the scum of the world had but a single
                              Message 14 of 18 , Nov 26, 2012
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                                How about a pneumatic die grinder like Humpty Fright sells cheap?


                                On Sun, Nov 25, 2012 at 7:32 PM, David G. LeVine <dlevine@...> wrote:
                                 

                                On 11/25/2012 04:10 PM, Pat Delany wrote:


                                Could you use coolant around an angle grinder? I had an extension shaft for an angle grinder  made by an expert machinist but the runout was terrible.

                                Pat

                                Yes, but...  It is not a good idea with an electric angle grinder unless you have a non-conductive coolant.  Chips tend to live in the coolant and tend to do bad things in electrical equipment.  Pneumatic angle grinders, however, are not a bad choice.  Consider that any tool in flood coolant will splash it everywhere except where you want it to go.

                                So, if you are ready to fully enclose the machine and add all the goodies flood coolant needs, it will work, but only expect it to work if you do so.

                                If you fully guard the ways and spindle, you can dry grind, but that is a pretty ambitious project, well beyond an MM.


                                Dave  8{)

                                --

                                "The first method for estimating the intelligence of a ruler is to look at the men he has around him."
                                Niccolo Machiavelli

                                NOTE TO ALL:

                                When forwarding emails, please use only "Blind Carbon Copy" or "Bcc" for all recipients. Please "delete" or "highlight & cut" any forwarding history which includes my email address! It is a courtesy to me and others who may not wish to have their email addresses sent all over the world! Erasing the history helps prevent Spammers from mining addresses and viruses from being propagated.


                                THANK YOU!




                                --
                                Nick A

                                "You know what I wish?  I wish that all the scum of the world had but a single throat, and I had my hands about it..."  Rorschach, 1975

                                "They that can give up essential liberty to obtain a little temporary safety deserve neither liberty nor safety."- Benjamin Franklin, Historical Review of Pennsylvania, 1759

                                "Suburbia is where the developer bulldozes out the trees, then names the streets after them." Bill Vaughan

                                "The price of apathy towards public affairs is to be ruled by evil men." Plato
                              • louis richardson
                                well those air powered die grinders do work,we mounted one to grind ID of some tubing on a lathe an they are WAY underpowered, took forever ,you could see
                                Message 15 of 18 , Nov 26, 2012
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                                  well those air powered die grinders do work,we mounted one to grind ID of some tubing on a lathe an they are WAY underpowered, took forever ,you could see grinding sparks , but after 30 minutes only .0005 of steel was removed, way too slow. and as to grinding grit being magnetic ,if your grinding steel or cast iron ,or other ferrous metals , then yes grit will be magnetic, i have cleaned many grinding coolant tanks in my day and all have magnets in them to catch grit, you wipe off grit into trash can and put cleaned magnet back into coolant tank.

                                  --- On Mon, 11/26/12, Nick Andrews <nickjandrews@...> wrote:

                                  From: Nick Andrews <nickjandrews@...>
                                  Subject: Re: [multimachine] Grinding comments
                                  To: multimachine@yahoogroups.com
                                  Date: Monday, November 26, 2012, 11:43 AM

                                   
                                  How about a pneumatic die grinder like Humpty Fright sells cheap?


                                  On Sun, Nov 25, 2012 at 7:32 PM, David G. LeVine <dlevine@...> wrote:
                                   
                                  On 11/25/2012 04:10 PM, Pat Delany wrote:


                                  Could you use coolant around an angle grinder? I had an extension shaft for an angle grinder  made by an expert machinist but the runout was terrible.

                                  Pat

                                  Yes, but...  It is not a good idea with an electric angle grinder unless you have a non-conductive coolant.  Chips tend to live in the coolant and tend to do bad things in electrical equipment.  Pneumatic angle grinders, however, are not a bad choice.  Consider that any tool in flood coolant will splash it everywhere except where you want it to go.

                                  So, if you are ready to fully enclose the machine and add all the goodies flood coolant needs, it will work, but only expect it to work if you do so.

                                  If you fully guard the ways and spindle, you can dry grind, but that is a pretty ambitious project, well beyond an MM.


                                  Dave  8{)

                                  --

                                  "The first method for estimating the intelligence of a ruler is to look at the men he has around him."
                                  Niccolo Machiavelli

                                  NOTE TO ALL:

                                  When forwarding emails, please use only "Blind Carbon Copy" or "Bcc" for all recipients. Please "delete" or "highlight & cut" any forwarding history which includes my email address! It is a courtesy to me and others who may not wish to have their email addresses sent all over the world! Erasing the history helps prevent Spammers from mining addresses and viruses from being propagated.


                                  THANK YOU!



                                  --
                                  Nick A

                                  "You know what I wish?  I wish that all the scum of the world had but a single throat, and I had my hands about it..."  Rorschach, 1975

                                  "They that can give up essential liberty to obtain a little temporary safety deserve neither liberty nor safety."- Benjamin Franklin, Historical Review of Pennsylvania, 1759

                                  "Suburbia is where the developer bulldozes out the trees, then names the streets after them." Bill Vaughan

                                  "The price of apathy towards public affairs is to be ruled by evil men." Plato
                                • oldhermit
                                  My son used a HF grinder to enlarge the holes in some lawnmower blades. An expensive drill bit dulled and wouldn t go through and blue grinders wore out too
                                  Message 16 of 18 , Nov 28, 2012
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                                    My son used a HF grinder to enlarge the holes in some lawnmower blades. An expensive drill bit dulled and wouldn't go through and blue grinders wore out too quickly but pink, stone grinders did the job.
                                    Harold
                                    --- In multimachine@yahoogroups.com, louis richardson <louisrfnauto@...> wrote:
                                    >
                                    > well those air powered die grinders do work,we mounted one to grind ID of some tubing on a lathe an they are WAY underpowered, took forever ,you could see grinding sparks , but after 30 minutes only .0005 of steel was removed, way too slow. and as to grinding grit being magnetic ,if your grinding steel or cast iron ,or other ferrous metals , then yes grit will be magnetic, i have cleaned many grinding coolant tanks in my day and all have magnets in them to catch grit, you wipe off grit into trash can and put cleaned magnet back into coolant tank.
                                    >
                                    > --- On Mon, 11/26/12, Nick Andrews <nickjandrews@...> wrote:
                                    >
                                    >
                                    > From: Nick Andrews <nickjandrews@...>
                                    > Subject: Re: [multimachine] Grinding comments
                                    > To: multimachine@yahoogroups.com
                                    > Date: Monday, November 26, 2012, 11:43 AM
                                    >
                                    >
                                    >
                                    >  
                                    >
                                    >
                                    >
                                    > How about a pneumatic die grinder like Humpty Fright sells cheap?
                                    >
                                    >
                                    >
                                    >
                                    > On Sun, Nov 25, 2012 at 7:32 PM, David G. LeVine <dlevine@...> wrote:
                                    >
                                    >
                                    >  
                                    >
                                    >
                                    >
                                    >
                                    >
                                    > On 11/25/2012 04:10 PM, Pat Delany wrote:
                                    >
                                    >
                                    >
                                    >
                                    >
                                    > Could you use coolant around an angle grinder? I had an extension shaft for an angle grinder  made by an expert machinist but the runout was terrible.
                                    >
                                    >
                                    > Pat
                                    > Yes, but...  It is not a good idea with an electric angle grinder unless you have a non-conductive coolant.  Chips tend to live in the coolant and tend to do bad things in electrical equipment.  Pneumatic angle grinders, however, are not a bad choice.  Consider that any tool in flood coolant will splash it everywhere except where you want it to go.
                                    >
                                    > So, if you are ready to fully enclose the machine and add all the goodies flood coolant needs, it will work, but only expect it to work if you do so.
                                    >
                                    > If you fully guard the ways and spindle, you can dry grind, but that is a pretty ambitious project, well beyond an MM.
                                    >
                                    >
                                    > Dave  8{)
                                    >
                                    >
                                    > --
                                    >
                                    > "The first method for estimating the intelligence of a ruler is to look at the men he has around him."
                                    > Niccolo Machiavelli
                                    >
                                    >
                                    > NOTE TO ALL:
                                    > When forwarding emails, please use only "Blind Carbon Copy" or "Bcc" for all recipients. Please "delete" or "highlight & cut" any forwarding history which includes my email address! It is a courtesy to me and others who may not wish to have their email addresses sent all over the world! Erasing the history helps prevent Spammers from mining addresses and viruses from being propagated.
                                    >
                                    > THANK YOU!
                                    >
                                    >
                                    >
                                    >
                                    > --
                                    > Nick A
                                    >
                                    > "You know what I wish?  I wish that all the scum of the world had but a single throat, and I had my hands about it..."  Rorschach, 1975
                                    >
                                    > "They that can give up essential liberty to obtain a little temporary safety deserve neither liberty nor safety."- Benjamin Franklin, Historical Review of Pennsylvania, 1759
                                    >
                                    > "Suburbia is where the developer bulldozes out the trees, then names the streets after them." Bill Vaughan
                                    >
                                    > "The price of apathy towards public affairs is to be ruled by evil men." Plato
                                    >
                                  • Pierre Coueffin
                                    I recently had some trouble cutting a 3/4 hole in some chrome moly for a new hydraulic piston. Killed the edge on drill bits pretty fast. Carbide masonry
                                    Message 17 of 18 , Nov 28, 2012
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                                      I recently had some trouble cutting a 3/4" hole in some chrome moly for a new hydraulic piston.  Killed the edge on drill bits pretty fast.

                                      Carbide masonry bits worked pretty good though.
                                    • Chris Tofu
                                      everyone is getting blown out about runout. Now I ve never tried it, but some people will mark the workpiece w/a sharpie then approach it carefully w/a
                                      Message 18 of 18 , Dec 3, 2012
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                                        everyone is getting blown out about runout. Now I've never tried it, but some people will mark the workpiece w/a sharpie then approach it carefully w/a grinding stone (by whatever means), and monitor the progress. It depends on what you're trying to accomplish - bring the surface into greater tolerance or improve the finish (often it goes hand in hand). If you were to run your carriage up and down (back and forth rather) a workpiece with a spinning grinding stone, couldn't you sneak in incrementally, measuring often? Do I sound crazy? This isn't production shop methodology. You can always remark the workpiece, and when the surface of the rod say starts to approach a suitable ground finish, you measure, remark, and sneak in some more if necessary. Repeating as often as necessary.

                                         What about using oily emery paper on a spinning fixture to improve a bore, say to take a spindle? There are definitely ways of polishing or grinding to get the tolerance you need.

                                         Ever heard of lathe filing? How many people on this list have tried that???
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