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  1. #31
    Yup same on the back - narrowed them enough to just squeeze within my current machine's work space so can do them both as single piece now.

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  3. #32
    Did sb tell you already to rid of that ridiculous Y Hiwin design? Why would you need 2 rails each side? You need one rail and 2 blocks, size 20 which have 100 times the specs higher than your machine can weight or 10x force on them.

    Before rendering the design, better think how you will mount all together. Especially how will adjust and fit things and with your design especially how you will square the Y rails/ yes again the Y rails./

    While side mounting is very beautiful is very hard to mount them properly in DIY design, thats why people use epoxy and mount them horizontally. Or as per your design- all MUST be Machined on mill so you fit it right.

    Same as front/back mounting ball screw supports.

    So the way i see it- nothing wrong with all that if you are to mill all pieces on a mill/ not your old CNC/ . If not- the result will be mediocre concerning precision
    project 1 , 2, Dust Shoe ...

  4. #33
    Quote Originally Posted by Boyan Silyavski View Post
    Did sb tell you already to rid of that ridiculous Y Hiwin design? Why would you need 2 rails each side? You need one rail and 2 blocks, size 20 which have 100 times the specs higher than your machine can weight or 10x force on them.
    I told him that 12 days ago, the first time I saw it.
    Gerry
    ______________________________________________
    UCCNC 2017 Screenset

    Mach3 2010 Screenset

    JointCAM - CAM for Woodworking Joints

  5. #34
    Yeah yeah, just haven't had time to work on that part yet as i've been re-designing the x-axis gantry and the z-axis first.

    Boyan - plan was to mount the rail to the 45x90 and then level it to the ecocast plate bed before tightening down all the screws, which would give alignment in the Z-axis. I suppose you are suggesting that the flatness of the extrusion will leave it slightly "wavey" in the horizontal axis?

    What about mounting a 20mm ecocast plate to the extrusion and then the rail to the plate, similar to what i'm ending up doing with the X-Axis?
    Last edited by Zeeflyboy; 19-02-2017 at 02:56 PM.

  6. #35
    I am speaking about how you would level the long rails that gantry moves on them / Y/- in the Z plane to be on one plane and at the same time to be flat . I am not so worried about the flatness as you say you will be using Ecocast plate.
    project 1 , 2, Dust Shoe ...

  7. #36
    So the plan was to mount the ecocast bed plate, then using a shim between one of the Y-Carriages and the underside of the bed plate I could fasten the screws moving the carriage as I go, which would end up with the rails level to the ecocast bed surface.

    The end pieces I have designed a pocket in the back sides to accept the 45x90 extrusions, which keeps the spacing between front and back consistent and (assuming the shop cuts the extrusions square) should keep things squared up too, and was planning on adding a couple of corner brackets to help keep the squareness of the frame acceptable.




    So the only thing that can cause significant issues as far as I can see is that I'm effectively relying somewhat on the flatness of the 45x90x1000mmm extrusions to provide the straightness in the horizontal plane. If the extrusions are slightly bent for example then I could get a slight curve when travelling fore/aft in the Y-axis... that would need fairly accurate shimming to get rid of.

    Could be an option to get some 20mm ecocast plate to mount to the 45x90mm and then mount the rails to that perhaps?

    e.g:

    Last edited by Zeeflyboy; 19-02-2017 at 03:33 PM.

  8. #37
    Another potential option perhaps would be to re-design around this misumi milled profile? https://us.misumi-ec.com/vona2/detai...689340/?Inch=0

    Not sure of the cost or availability however.

  9. #38
    Seems alright. I would have done it same way. using straight edge you can make sure all is ok
    project 1 , 2, Dust Shoe ...

  10. #39
    Sorry just to be clear for me - you are saying you would do the levelling the same way with the shim, or the mounting of 20mm plate to the extrusion before mounting the rail, or going with the milled extrusion?

  11. #40
    fifa's Avatar
    Lives in bristol, United Kingdom. Last Activity: 4 Weeks Ago Has been a member for 0-1 years. Has a total post count of 30. Received thanks 2 times, giving thanks to others 0 times.
    Boyan is right

    2 rails each side are nonsense. The result will be huge loads to the rail bearings due to thermal distortions, nonparallel cuts etc. General problems with gantry types is non-optimised stiffens. Torsional displacement of the gantry beam define the stiffens of whole system.
    Everything is assembled from standard profiles. I-s are known, do the simple test and apply load of 100N at the end of the cutter.
    Don't be surprised.

    regards

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