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  • Re-aligning a good vice.

    Thought some may like to see how I went about aligning a top quality vice that was just out a bit... I did it mainly to practice my scraping for alignment skills... I found it a very interesting and well worth adventure, not only the finished product but I found getting there was the most valuable part..

    First up it is a 6" vice that came with my milling machine when I bought it... It has performed top my expectations and only had a few niggling things wrong with it... I had no need to re-align it other then, because I wanted to...

    I did not actually take pictures when I was doing it mainly because for all I knew it may have turned out a complete fail... Which amazingly it didn't..

    So here goes...

    First up a I disassembled the vice, and scraped the base flat to about 5 SPI (spots per inch) I discovered 130mm radius blades are best kept for people who are experienced Biax users.. The ends are easy to dig in..



    I then did a breaking up scrape on the opposite side.. Then placed it on the surface plate and found the lowest point and highest point... I discovered one end was 0.04mm higher then the other.. I got the pen out and marked out different stages so I had some idea where to scrape.. thusly



    I then scraped only for alignment at this stage, at no point did I spot the surface for contact, I did measurements as I went to keep an eye on my progress..

    When I had it coming in at mostly the same height all over I started spotting it in... Eventually working up to this point



    Upon measuring I have one end 0.01mm (0.0004") higher then the other... TO me this is good enough... I could bring it lower with a couple more scraping passes if I wanted

    Here is an X test with my "straight edge" which is a gib off a scrapped milling machine...

    Precision takes time.

  • #2
    The X test is to check for twist...

    I then put a parallel across the "ways" and measured it.... The measurement came up with very minimal movement of the dial gauge. (Mitutoyo 0.01mm)



    Upon moving to the fixed jaw which is also made of cast iron, I scraped the top surface flat. I ended up going a bit silly with the required SPI and ended up with a fine even splattering over the surface... Probably nearing 25-30SPI

    I started with this



    And ended with this.



    I then flipped it upside down and with the dial indicator worked out where to scrape by finding the highest side and working from there.

    I could keep an eye on parallelism between the two sides with my straight edge along with the dial indicator together to complement one another.

    Precision takes time.

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    • #3
      That is as far as I have got to at this stage... To be continued...
      Precision takes time.

      Comment


      • #4
        Thanks for putting the photos up RC, nice job! I appreciate you did this as much as an exercise as for the end result but for my own interest I was wondering how you feel this process (scraping for alignment) would compare to first milling/fly cutting the faces to align and then scraping for bearing?

        Also, I can't recall if you have a surface grinder? When I finally get a few moments I'll go pick up my grinder and this would probably be a good process to go through for me to try it out, but grinding instead of scraping.

        Pete

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        • #5
          Originally posted by .RC.
          ...I discovered 130mm radius blades are best kept for people who are experienced Biax users..
          Lovely job.

          Could you just expand slightly on this. What range of blades are available and what size should the inexperienced user use (larger or smaller radius)?

          Thanks.

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          • #6
            I really don't know Pete. It probably all depends on how accurate your setup is.. I have no doubt you could get better then what I have done with a grinder, but a grinder capable of doing it might cost a lot..

            I don't have a surface grinder, just two tool and cutter grinders.. The little Chevalier and the WW2 era Macson #2 which I have to rescrape.. It was rescraped by the previous owner but I think he did not own a straight edge going by the banana shaped ways..

            Onto more pictures..

            I do not own a granite or cast iron square, and the only square I have that I trust is a Brown and Sharpe one... I had to get the plane where the jaw bolts on square to the movable jaw, so I set it up thusly... I could slide a 0.04mm feeler gauge just into the top..



            I scraped it square and got what I believe a good enough bearing for the hardened jaw to bare against... The bearing coverage is not all over the surface but it is over enough of it for a non wearing side..

            Precision takes time.

            Comment


            • #7
              Originally posted by .RC.
              I really don't know Pete. It probably all depends on how accurate your setup is.. I have no doubt you could get better then what I have done with a grinder, but a grinder capable of doing it might cost a lot..
              Ok, I couldn't get an idea of scale from the photos, by grinder "capable" do you mean for the size of that vice?

              Originally posted by .RC.
              It was rescraped by the previous owner but I think he did not own a straight edge going by the banana shaped ways..
              Ha ha, maybe it was the same guy who built parts of my house. If he owned a level he sure as heck didn't want to wear it out!

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              • #8
                Ok, I couldn't get an idea of scale from the photos, by grinder "capable" do you mean for the size of that vice?
                No I meant one accurate enough.. As I understand there are surface grinders and there are surface grinders.. Most can work to one type of accuracy standards, but to work to better standards means you have to jump up a notch in quality of machine.. A bit like a standard South Bend can do work up to a certain standard, but to work to higher standards means you need a 10EE with the resultant extra cost that is to buy.. But then I have never done any surface grinding so am probably talking out my arse...
                Precision takes time.

                Comment


                • #9
                  Originally posted by djc
                  Could you just expand slightly on this. What range of blades are available and what size should the inexperienced user use (larger or smaller radius)?
                  Generally the larger the radius, the wider the cut, but tilt it just a bit and you will put a deep scratch in what you are scraping..

                  I have madeup blades with a 130mm, 90mm and 60mm radius.. I use the 90 for roughing and 60 for finishing... If I wanted a better SPI (say 40) then I would move down to a 40mm radius blade..
                  Precision takes time.

                  Comment


                  • #10
                    Blades

                    http://www.dapra.com/biax/scrapers/blades.htm

                    Comment


                    • #11
                      Scraping

                      Very nice job indeed .RC.

                      You should be very pleased with and proud of that job - and yourself.

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                      • #12
                        Totally agree with oldtiffie beautiful precise work.
                        Alan

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                        • #13
                          way to go RC, that is an excellent scraping project that will add a lot value - you end of with a perfect vise. It could be ground, but the value of scraping is a) lots of guys don't have grinders and to a less extent b) it might be the more accurate approach. Reasons for b) include quality/condition of the grinder and the difficulties of eliminating clamping forces affecting things....whereas the scraping gets it to the flatness of your surface plate. I'll admit point b) is slightly ivory tower for this project; a skilled grinder on a half decent machine would have no trouble doing an excellent job, but the power of scraping projects like this is that it lets one work the the highest levels of accuracy with but simple hand tools
                          .

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                          • #14
                            RC, looking pretty good. I started on my Sheldon Lathe compound today. I''ll have to take some snaps.
                            Warren

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                            • #15
                              Originally posted by .RC.
                              Generally the larger the radius, the wider the cut, but tilt it just a bit and you will put a deep scratch in what you are scraping..

                              I have madeup blades with a 130mm, 90mm and 60mm radius.. I use the 90 for roughing and 60 for finishing... If I wanted a better SPI (say 40) then I would move down to a 40mm radius blade..
                              Interesting. I am a scraping wanna-be with no experience, but I would have thought the opposite choices would be made. A smaller radius would tend to cut deeper and would be used for roughing. While the longer radius would spread the cutting out over a larger area but the cut would be less deep. This would be both a finer cut and also have a better smoothing effect. I know that pressure and angle has something to do with it, but where and why am I wrong?

                              As I said I have no experience and am not argueing, just trying to learn.
                              Paul A.
                              SE Texas

                              Make it fit.
                              You can't win and there IS a penalty for trying!

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