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Need some help with making a linear feed table

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  • Need some help with making a linear feed table

    I'm working on a surface grinder attachment for my belt grinder. I put everything together, but I'm not happy with the linear guide that I sourced. So, I thought I'd attempt to make my own.

    I've found a few photos online of similar DIY versions that are used for the same purpose. One obviously has some sort of gib adjustment, but otherwise I'm looking for ideas how to keep the side-side and up-down movement out of the table.


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  • #2
    Do you intend to build a machine that will hold a sub <.001 dimension repeatedly?

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    • #3
      Mount the bearings on eccentrics to take up the tolerances? Monarch used that method on the 10EE taper attachment to allow low friction without excessive play, more fiddly than a gib to set up correctly - do you have any pics that show the whole thing and how the different axes are built?

      And, yes, how accurate are you working towards?

      Dave H. (the other one)
      Rules are for the obedience of fools, and the guidance of wise men.

      Holbrook Model C Number 13 lathe, Testa 2U universal mill, bikes and tools

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      • #4
        Here's a diagram and a photo of what I'm making...


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        • #5
          I finished mine, using the linear guide below as the feed. Same as in the photo above.

          I'm using it for knifemaking, and I found that if I ground both sides of a 8-12" bar of steel, the tolerances were within .001-.002. Which is fine for what I'm doing.

          Problem was, the table started to develop some side-to-side movement. I just don't think it's sturdy enough for this use. So, I'd like to make something myself. I have some 1/2"x4" aluminum bar that I plan to use. But I want to make sure I can take out as much movement as possible, and it will be robust enough




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          • #6
            is that a magnetic bar closest to the wheel, to hold the knife? That's pretty cool. My first thought when I saw that is that there's a lot of leverage there for a relatively small slide (the black bit underneath). What other tools do you have to make the XY table?

            A standard option to control off axis movement would be adjustable dovetails, like you find on a mill or a lathe. You may even be able to add one to that black slide you posted above. You'd really need a mill to make one though.

            Another option which might be easier to implement would be round linear rails and bearings, like the ones they use on 3D printers. They're relatively cheap, you can get them in all kinds of sizes and you should be able to build an XY table with them with basic tools and some care. I'd make the lower (Y) part wider though. That will help it resist the twisting of the X axis. Also think about some kind of dust protection or any slide you use/ make won't stay very precise for long.

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            • #7
              Why not buy an Inwin linear rail and bearings? They are strong, accurate, rigid enough for heavy machining duties.

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              • #8
                Originally posted by mattthemuppet View Post
                is that a magnetic bar closest to the wheel, to hold the knife? That's pretty cool. My first thought when I saw that is that there's a lot of leverage there for a relatively small slide (the black bit underneath). What other tools do you have to make the XY table?
                Yes, it's a piece of 6061 that I milled slots and epoxied in magnets to hold the blade

                But yeah, I think the table in the photo just wasn't the proper tool for the job. I have a LMS Mini Mill and a drill press, that's what I used for the original version I made.


                Originally posted by mattthemuppet View Post
                A standard option to control off axis movement would be adjustable dovetails, like you find on a mill or a lathe. You may even be able to add one to that black slide you posted above. You'd really need a mill to make one though.

                Another option which might be easier to implement would be round linear rails and bearings, like the ones they use on 3D printers. They're relatively cheap, you can get them in all kinds of sizes and you should be able to build an XY table with them with basic tools and some care. I'd make the lower (Y) part wider though. That will help it resist the twisting of the X axis. Also think about some kind of dust protection or any slide you use/ make won't stay very precise for long.
                I think I might try some version of this slide;

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                And mill some sort of t-slot in between the two pieces. It would act as a gib, I suppose. And I could also use it to snug down the piece completely. If I still had any movement, I could add a gib on the side, similar to what they used in the photo.

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