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How to check Harig Super 6 x 12 surface grinder

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  • How to check Harig Super 6 x 12 surface grinder

    I have a chance to buy an old Harig Super 6 x 12 surface grinder. The current owner does not know much about this grinder. I have never had or used a surface grinder either. The asking price is $1500 and the owner claims it is fully operational (but he never used it). Do you think it is reasonable price for PA?

    The owner thinks he can get it hooked up to prepare it for inspection. What do you think I should check when I go there? I have attached a few pictures of the machine. It looks like it has something resembling an oil can on the right side of the column. I think it is aftermarket. What is it?
    The magnetic chuck appears to be aftermarket as well. Are SPI chucks any good? Any idea how old is this machine?

    I do not think the owner has any special tools for this machine. I may not be able to remove the grinding wheel hub to look at the spindle end. Any suggestions here?

    Any good advice will be appreciated.

    Mike




    Last edited by mikey553; 06-17-2017, 07:25 PM.

  • #2
    There is one more picture here - I was not allowed to post more than 4 pictures at once.

    Mike

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    • #3
      Originally posted by mikey553 View Post
      There is one more picture here - I was not allowed to post more than 4 pictures at once.

      Mike

      Take some stones, parallels, angle plate and a test indicator with you. Check the table X and Y with the chuck on and then off of the table. The runout of the chuck will tell you if you can use the grinder as is with the mag chuck. The runout of the table will tell you how badly worn the machine is. Typically the chuck is ground in place to compensate for the wear in the ways so the measurements of that alone might indicate all is well.

      Parallels are for the Y axis check, angle plate for the Z.

      I didn't do this when I bought my TML. X and Y ways were each out 0.020". Z was 0.004". Had to scrape the entire machine back to square. Then of course the chuck was off 20 thou in 2 directions. More scraping!

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      • #4
        You need to check if the body is attached to the base , my grinder comes in 2 pieces the top sets on 3 points so it doesn't rock and when I brought it home I had 2 pieces to strap down in my trailer. That hand pump is not original on the back side of the column see the cover with the red printing on it if you take that off you should see an oil reservoir with a pump in it to oil the column ways on the front of the column by the hand wheel you can see a sight window that the pump flows in to , as to value I wouldn't pay more than $800 if it has the pump , the pump is 220 V 1~ .
        Last edited by duckman; 06-17-2017, 10:53 PM.

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        • #5
          The recognised "Gold Standard" reference (book)for this type and levelling of machine tool reconditioning is pretty well recognised as being:


          Machine Tool Reconditioning and Applications of Hand Scraping‎

          https://www.google.com.au/#q=Machine...=1497755261723

          And some further related publications:

          https://www.google.com.au/search?q=m...w=1536&bih=719
          Last edited by oldtiffie; 06-17-2017, 11:41 PM.

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          • #6
            It looks like it has something resembling an oil can on the right side of the column. I think it is aftermarket. What is it?
            Maybe it's one of those one shot oilers used to pump a little oil onto the ways.

            The magnetic chuck appears to be aftermarket as well. Are SPI chucks any good?
            That looks like a fine pole chuck, which I think is the preferred type. Is it any good? Place a piece of steel on it, turn it on, and try to pull the piece
            of steel off.

            $1500 sounds like a lot if it needs any major work, just my unqualified opinion.

            It's hard to tell, but it looks like a cutting wheel mounted on the spindle.

            Any good advice will be appreciated.
            The best advice I can offer is if you can find someone local who knows their way around a surface grinder, bring them with you.
            Last edited by RichR; 06-17-2017, 11:14 PM.

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            • #7
              Manual or automatic grinder?
              Looks like current owner may have bought it on speculation (sold cheap at auction).
              Not powered, no way to test the spindle.
              Import chuck. (might be okay)
              You're not exactly living in the equivalent of the machine tool desert, I'd pass unless the price dropped to about half.

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              • #8
                Thank you guys for your help. I have access to the owners manual and it has several machine checks as well.
                The machine will be powered during inspection and I will let the spindle run for 15-20 minutes, then dress the wheel and grind a small flat part to check a surface finish.

                You gave me some idea how to check the machine for accuracy. I will remove the chuck and then indicate the machine table. I also have a decent 2-4-6 block, which can be used to check if X, Y and Z are perpendicular to each other.

                The oiler on the column worries me. The original oil pump is either not operational or not even there.

                I do not see any mention of wheel balancing in the manual. I think the original wheel hubs did not have any provision for balancing weights. Is it common not to balance the wheel on these small grinders?

                Comment


                • #9
                  Originally posted by rickyb View Post
                  Take some stones, parallels, angle plate and a test indicator with you. Check the table X and Y with the chuck on and then off of the table. The runout of the chuck will tell you if you can use the grinder as is with the mag chuck. The runout of the table will tell you how badly worn the machine is. Typically the chuck is ground in place to compensate for the wear in the ways so the measurements of that alone might indicate all is well.

                  Parallels are for the Y axis check, angle plate for the Z.

                  I didn't do this when I bought my TML. X and Y ways were each out 0.020". Z was 0.004". Had to scrape the entire machine back to square. Then of course the chuck was off 20 thou in 2 directions. More scraping!
                  Yes, check linear travel with a thick parallel. Checking vertical accuracy with an angle plate? It's good to know how close it is, but that can always be fixed with shims under the column bolts. Unless you're doing a lot of sidewheeling or face grinding with a cup wheel it doesn't matter. If you plan to do that stuff, also make sure the spindle is parallel to the table movements.

                  Sent from my XT1053 using Tapatalk

                  Comment


                  • #10
                    Originally posted by RichR View Post
                    Maybe it's one of those one shot oilers used to pump a little oil onto the ways.


                    That looks like a fine pole chuck, which I think is the preferred type. Is it any good? Place a piece of steel on it, turn it on, and try to pull the piece
                    of steel off.

                    $1500 sounds like a lot if it needs any major work, just my unqualified opinion.

                    It's hard to tell, but it looks like a cutting wheel mounted on the spindle.


                    The best advice I can offer is if you can find someone local who knows their way around a surface grinder, bring them with you.
                    A lot of times a surface grinder will be designated for cutoff work (pins, primarily) once their accurate service life is over. This isn't always a deal breaker, as in many cases they're still good for what the average home shop needs. But, look for telltale signs of wear.

                    Sent from my XT1053 using Tapatalk

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                    • #11
                      Originally posted by mikey553 View Post
                      Thank you guys for your help. I have access to the owners manual and it has several machine checks as well.
                      The machine will be powered during inspection and I will let the spindle run for 15-20 minutes, then dress the wheel and grind a small flat part to check a surface finish.

                      You gave me some idea how to check the machine for accuracy. I will remove the chuck and then indicate the machine table. I also have a decent 2-4-6 block, which can be used to check if X, Y and Z are perpendicular to each other.

                      The oiler on the column worries me. The original oil pump is either not operational or not even there.

                      I do not see any mention of wheel balancing in the manual. I think the original wheel hubs did not have any provision for balancing weights. Is it common not to balance the wheel on these small grinders?
                      A lot of people claim you don't have to balance wheels, but I disagree. There's no reason not to balance them and you can usually see a surface finish increase when properly balanced. Wheels over 60 or 80 grit tend to show when they're not perfectly balanced, but I have a 46 grit wheel on my machine now that's not perfect and still grinds nicely. Also depends on the hardness of the part, if the part is hard it takes more cutting pressure to cut which can dampen/hide vibrations.

                      Sent from my XT1053 using Tapatalk

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                      • #12
                        "Wheel balancing" usually does or can refer to "balancing hubs" that are usually limited/restricted to the spindles of surface grinders (and/but not all surface grinders have them) and not tool and cutter grinder spindles.

                        On my surface grinder I usually don't bother with "balancing" as if I leave the balancing hub weights in the "neutral" positions it all works well enough.

                        Replacement hubs - if available - are not cheap.

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                        • #13
                          They are not cheap at all, but they can be made if you have the time. The taper can be a bit tricky but that's not difficult, just some trial and error on a scrap piece.

                          Sent from my XT1053 using Tapatalk

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                          • #14
                            1500 is way too high for a small surface grinder like this. They typically go at auctions for less than half that. I recently bid $150 for one and realized it was 4 hours away. I sweated until the last minute before "losing" the bid by $20. Read the fine print at auctions! I have seen auto feed Cincinnati grinders go for nearly scrap price. the Harig is a nice size for a small shop, and can be moved without heavy rigging so it has good value if it is still accurate and the spindle bearings are OK. If you have to rebuild the spindle it is only worth dragging home if you pay scrap price....my opinion.


                            Sent from my iPad using Tapatalk

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                            • #15
                              I paid $300.00 for the one I bought about 2 years ago and when I got it home I found out the oil pump was shot and not working but they are are still readily available from the pump manufacturer. Mine has a compound angle magnetic chuck that is worth more than the grinder. My kids should be able to sell it easily when I am no longer able to use it or my other machines. I am located in the St. Louis area for what its worth.

                              Jack
                              I'm Happy because I am retired

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