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  • Scrapers ... again ...

    Well I've got a couple of threads I keep meaning to post about this shaper buisness. Anyway, I need to make a replacement gib and I thought now is as good a time as ever to start learning how to scrape. I've got a copy of "Machine Tool Reconditioning" to borrow. Enco has a "Inspection Grade A" surface plate on sale. (Unilateral accuracy of .0001") I'm thinking I'll get the largest one that they'll ship for free, which is a 18 by 12 I believe. Sure I'd like to have a huge one, but this will do for now.

    Then there are the scrapers. Rather than investing in a diamond wheel and using carbide, I was thinking about going the HSS route. Since this is a gib for the tool slide on a shaper, I'm not overly concerned with accuracy, anyway. Anyhow, what are your thoughts on this:

    http://www.use-enco.com/CGI/INSRIT?P...PMAKA=240-3363

    It may just be a one time use deal, but that's ok. At least a steel scraper will be easier to sharpen. (And it will be used on mild steel)

    So what do you guys think?

    p.s. I downloaded that write-up from the Lawrence Livermore Laboratory on hand scraping.

  • #2
    Originally posted by Fasttrack
    Well I've got a couple of threads I keep meaning to post about this shaper buisness. Anyway, I need to make a replacement gib and I thought now is as good a time as ever to start learning how to scrape. I've got a copy of "Machine Tool Reconditioning" to borrow. Enco has a "Inspection Grade A" surface plate on sale. (Unilateral accuracy of .0001") I'm thinking I'll get the largest one that they'll ship for free, which is a 18 by 12 I believe. Sure I'd like to have a huge one, but this will do for now.

    Then there are the scrapers. Rather than investing in a diamond wheel and using carbide, I was thinking about going the HSS route. Since this is a gib for the tool slide on a shaper, I'm not overly concerned with accuracy, anyway. Anyhow, what are your thoughts on this:

    http://www.use-enco.com/CGI/INSRIT?P...PMAKA=240-3363

    It may just be a one time use deal, but that's ok. At least a steel scraper will be easier to sharpen. (And it will be used on mild steel)

    So what do you guys think?

    p.s. I downloaded that write-up from the Lawrence Livermore Laboratory on hand scraping.
    I think you should search for all the posts made my Forest addy on scraping and go the carbide route and make your own scraper as Forrest does.

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    • #3
      Originally posted by BillH
      I think you should search for all the posts made my Forest addy on scraping and go the carbide route and make your own scraper as Forrest does.
      But it seems like so much work

      Actually I just read Forrest's response to your post back in 2003, Bill, about scrapers. I think I will go with a HSS or carbon steel scraper, for now. I don't mind touching up the scraper every couple of minutes. It's a small project and I don't have the money or time to shoot for the carbide scraper and proper tools for sharpening the carbide right now. Some day, but not yet! I can see carbide is a much better choice for "serious" work. I'll put it on my wishlist.
      Last edited by Fasttrack; 03-31-2009, 04:19 PM.

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      • #4
        I bought one of those Enco scrapers quite a while back, just because I was already making and order, and it was cheap, so I figured I would see if it was worth anything at all. Frankly, I think it may be over priced. It does not hold up well at all. The edge just erodes away with very little accomplished. In my opinion, a good quality old file is better for any ferrous work.

        I also picked up a Nicholson which does work pretty well, and I use it here and there. But it is VERY hard/brittle, so it won't take any abuse at all without fracturing the edge.
        Russ
        Master Floor Sweeper

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        • #5
          Alright, well that's a pretty convincing argument. I'll look for an old file or maybe I can braze a piece of tool steel to a steel shank?

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          • #6
            Originally posted by Fasttrack
            I think I will go with a HSS or carbon steel scraper, for now.
            .
            i know the blades Anderson sells are HSS, but think there is no advantage to hss over carbon, unless you one really really fast scraper

            It's a small project
            whats a small project, that 36" (or what the monster is) shaper? you'll be sorry
            .

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            • #7
              I've been considered making an Anderson style scraper from conduit. You could do that, but with HSS parting blades mounted with silver solder on the business end.
              Russ
              Master Floor Sweeper

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              • #8
                I might have to try that ... I suppose Mcgyver is right, HSS isn't really neccessary. I got a whole bunch of it when I bought the shaper, though. I haven't been "in the buisness" long enough to acquire any dull files, on the other hand. Oh, I've got Rex 95, T15 and Tantung G. I think those all are harder than M2, but I could be wrong...

                LOL - Yep it's for the 26" shaper. I need to make a new gib for that tool slide. I thought I'd try some scraping and see if I can scrape in a new gib. The gib only needs to be about 12" long, so an 18 by 12 flat doesn't seem too bad. Plus it's the largest with the free shipping
                Last edited by Fasttrack; 03-31-2009, 08:32 PM.

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                • #9
                  Raining on the parade.

                  If it were me, I'd concentrate on the manufacture of the gib as that may be a sizable exercise in itself. It will or may have a 1/8" per foot (1:96) taper between the pressure faces. It will need to be made sufficiently accurately to be a good fit in the gib cavity (both faces) before scraping (if needed) is even considered let alone started.

                  I would bet that it will bend or bow under scraping unless very well balanced. A bent gib, if correct when straight can be inserted straight into the cavity and it will straighten as it goes in.

                  You seems to be assuming that the surfaces on which the gib contacts are straight and true - at least one may not be. If that is the case, scraping dead flat may be futile.

                  I would be more inclined to make the gib (milling and or hand-filing) such that equal gaps (feeler guages) are at each end when assembled. Even if the gib has adjusting screws (at least one - preferably two) on each end, and given that there will be wear on the ram dove-tails (both sides - the one one which rubs on the gib and the opposite/other one) as well as the mating bottom face of the ram and the flat face on which it slides.

                  I'd fit adjusting screws to the fixed dove-tail - just as there is on a lathe. They will adjust nicely (for) any irregularities so that you get an optimum (but never-the-less a compromise/d result) that WILL workas it does on many mills and lathe slide gibs.

                  I'd just scrape one face of the gib - the one that contacts the ram - for lubrication purposes - and even that is optional.

                  Optimally, ALL the rubbing and wearing surfaces on both the body of the shaper and the ram need to be scraped for it to be anywhere near perfect.

                  Unless it is for looks or appearance or for lubrication, scraping is pretty well an "all or bugger all" event.

                  I hope I have not rained on your parade.

                  Comment


                  • #10
                    It's not the ram gib, its the gib for the tool height adjustment. You've not rained on my parade at all. I've been thinking about how I was going to approach this for awhile.

                    The taper is actually, according to Forrest, usually .25" per 12". I've not verified that yet with the little stub of a gib I have remaining. Anyhow, the gib is flat on one side and tapered on the other. I intend to take a blank piece of steel and grind one face smooth on a surface grinder. Then it's over to a mill to machine the tapered face. Then it's back to the surface grinder to grind the taper.

                    Then it's time to scrape? I'm thinking of using the gib as a sort of master or straight-edge for the dovetail. I'm not sure yet ... I need to re-read Machine Tool Reconditioning

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                    • #11
                      FT, I'd strongly suggest a carbide blade -- they last much longer than steel, and you can sharpen them with a cheap dipstick diamond hone.
                      All that scraping I did making the reference plane on my Millrite I did with a powerscraper and hand-sharpening the carbide.

                      You can use any cheap 1/8" x 3/4" carbide blank for the blade. MSC, ENCO et all carry them.
                      "Twenty years from now you will be more disappointed by the things that you didn't do than by the ones you did."

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                      • #12
                        Has anyone tried TANTUNG? It works good on woodworking tools. Besides I recently got some at an estate auction for cheap.
                        re
                        Herm Williams

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                        • #13
                          Herm, Tantung (and Stellite) is a cobalt alloy. Cobalt adds high red hardness, and like McGyver says, red hardness isn't going to help, unless you're scraping really fast.
                          "Twenty years from now you will be more disappointed by the things that you didn't do than by the ones you did."

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                          • #14
                            Originally posted by lazlo
                            Herm, Tantung (and Stellite) is a cobalt alloy. Cobalt adds high red hardness, and like McGyver says, red hardness isn't going to help, unless you're scraping really fast.
                            I dunno, I'm pretty quick...

                            Rex 95 says the as-supplied hardness is 64-66 Rockwell C
                            The specs I could find on M2 tool blanks put it at 60-62 Rockwell C

                            Pretty big difference I'm going to snag a 1/2" wide carbide blank from Enco. That is the widest chunk of 1/8" carbide I can get in a short piece. I'm not saying I'll use it for sure, but for 4 bucks I'll toss it in the tool box!

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                            • #15
                              IIRC, Rex95 is T-8, which is hard as hell. Might make a good scraper, but it's really expensive, unless you found a bunch on Ebay...

                              If you can wait 'till the morning, I think I might have some carbide blanks I can send you.
                              "Twenty years from now you will be more disappointed by the things that you didn't do than by the ones you did."

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