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  • Dovetail Straightedge Casting

    Has anyone had any experience with this company: https://coreprintcastings.com/produc...-edge-casting/?

    I'm looking into materials to allow me to scrape in a cross slide and came across them. By the time I've ordered in a suitable piece of cast iron I figure I'll probably be at about the same cost, saves some machining time. Local to me as well. Would like to know if people found the castings to be of quality or not before I go down that route.


  • #2
    About a year ago I dropped into Small Tools Inc in Cleveland, and he had a pile of 45 degree dovetails that he was letting go "cheap". I picked up a 5', already scraped in, for $150. It was still straight according to my surface plate. He also had some camelbacks that were going for similar prices.

    This was just before he moved to his new location, so the price might have reflected "the less I have to move" phenominon. Anyway, I'd give him a call or send him an email. Can't hurt.

    (Not associated, no financial interest, your milage may vary, void where prohibited, a hell of a lot of settling has occured).

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    • #3
      and a local guys as well....interesting. Key question is whether they've been normalized or stress relieved. Cast iron is pretty good, but it would make you mental if it moved each scraping iteration
      .

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      • #4
        Denis Foster in Bellingham, WA makes a nice dovetail casting that's lighter than the solid ones and is designed to incorporate a level vial if desired. All reports are that the castings are well stress relieved. I don't know if he uses this forum but does participate on PM as dgfoster.

        No connection, beneficiary, etc.
        .
        "People will occasionally stumble over the truth, but most of the time they will pick themselves up and carry on" : Winston Churchill

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        • #5
          Problem is getting anything of this size/weight out of the US is going to cost me $100 just in shipping. Finding something local is a definite benefit in my eyes. Plus I can talk to the designer/manufacturer and perhaps pick up some tricks/info.

          I'm going to shoot them an email and see if they are normalized or stress relieved, that would probably be the deciding factor.

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          • #6
            They're obviously trying to come up with some cast finish-yourself products, but no traditional camel back straight edge. If you're back and forth and think to ask, maybe they have plans to make some. I wonder if its the foundry you see on the QEW, lakeside maybe the name?
            .

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            • #7
              I can get a hunk of durabar from speedy metals to make a prism for half the cost of the ones in the link. You need to hack the excess off but it will get you some valuable practice scraping. The stuff I got scraped very nicely once you got rid of the outside skin. No experience with the parts in the link, they look nice but the may or may not be nice inside. I'd still want to flycut the surfaces before I started scraping.

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              • #8
                Originally posted by gzig5 View Post
                I can get a hunk of durabar from speedy metals to make a prism for half the cost of the ones in the link. You need to hack the excess off but it will get you some valuable practice scraping. The stuff I got scraped very nicely once you got rid of the outside skin. No experience with the parts in the link, they look nice but the may or may not be nice inside. I'd still want to flycut the surfaces before I started scraping.
                In making the comparison, did note those prices are in dollarettes (CDN$) and that Durabar is stupidly expensive up here and given the cost international shipping there's little low cost choice

                Secondly, have you scraped a piece of durabar? I have and it did work well but it was a smaller, chunkier bit. For a long thin reference sending it out to be normalized or stress relieved would imo be a requirement, else it could be very frustrating. If you have scraped similar sized pieces as those and they were stable, maybe I'm overly worried about it, but I do believe its SOP for reference flats.

                .

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                • #9
                  I made an 13" prism (dovetail straight edge) like the ones on the website from a 1 1/2" square chunk I got from Speedy. I removed the outer layers about .080 deep and then cut the angle for the front and scraped it in on all sides. I printed it a couple months ago on the plate and it looks like it is the same pattern I had last I worked it a couple years ago. I'm no expert but I think getting rid of the hard outer skin is key to success. Once gone it cuts smoothly and I think it gets rid of asymetric stresses in the material. Will it move in the future? I don't know but it worked for me on the SB 10L carraige. I'll heat treat it if I ever have something else to go in the oven. It won't fit in my little HT oven. I need to recut the angle because I made it to 60 degrees and that isn't as useful as a 45.
                  Last edited by gzig5; 12-12-2019, 01:59 PM.

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                  • #10
                    Originally posted by gzig5 View Post
                    I can get a hunk of durabar from speedy metals to make a prism for half the cost of the ones in the link. You need to hack the excess off but it will get you some valuable practice scraping. The stuff I got scraped very nicely once you got rid of the outside skin. No experience with the parts in the link, they look nice but the may or may not be nice inside. I'd still want to flycut the surfaces before I started scraping.
                    Thats pretty much what I would do, get a chunk of DuraBar somewhere and work that.

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                    • #11
                      Dura Bar is a ductile iron, and IIRC ductile gets some of its qualities from a specialized heat treat regimen. Sending it out to be normalized or otherwise treated might change its characteristics.

                      I've also had good luck with it after getting any bark off.
                      .
                      "People will occasionally stumble over the truth, but most of the time they will pick themselves up and carry on" : Winston Churchill

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                      • #12
                        Still waiting for them to get back to me.

                        Yeah, Canada kind of sucks for sourcing things like DuraBar. Within a 100km radius I have steel mills and other heavy industry to the north, east, and west; yet to get DuraBar I'm either paying through the nose to ship it in from Buffalo or Detroit, or paying through the nose because the supplier doesn't want to bother with my small order. Hence my interest in finding a ready to finish machine and scrape straight edge that I could pick up in person locally.

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                        • #13
                          I wonder if there's some kind of scrap machine parts you could use to make the straightedge?

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                          • #14
                            Just following up on this - the company did eventually reply to my email and they say the castings are heat treated. I will most likely pick up one of the 12" dovetail castings to scrap in (eventually).

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                            • #15
                              You can get 12" dovetail castings from this guy in the UK. He doesn't normally post outside the UK but if you get desperate maybe I can help.

                              https://www.ebay.co.uk/itm/Engineer-...h/163532954064
                              Peter - novice home machinist, modern motorcycle enthusiast.

                              Denford Viceroy 280 Synchro (11 x 24)
                              Herbert 0V adapted to R8 by 'Sir John'.
                              Monarch 10EE 1942

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