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  1. #1
    Quote Originally Posted by Evengravy View Post
    Hey,

    I designed it this way just to give me scope for adjustments in each degree of freedom. I couldn't think of a better way of doing it to be honest, open to suggestions though.
    Ah makes a bit more sense now. I was working on your old setup and seeing all those holes which matched the profile ends I thought was fastening into ends.

    Carry on.!! . . Lol

    Edit: The drop bracket still needs some bracing thou.!! or a redesign of the whole thing.!.
    Last edited by JAZZCNC; 10-04-2020 at 05:58 PM.

  2. #2
    Quote Originally Posted by JAZZCNC View Post

    Edit: The drop bracket still needs some bracing thou.!! or a redesign of the whole thing.!.
    Yea, I was planning some welded triangulation braces between the two parts once it's all aligned properly, the overhanging section that mates with the ballscrew is annoying me but I'll come up with something to strengthen it up. Front plate will be heavy (15mm) but I know that will be a weak spot for flex. I'll play around with the design a bit more in CAD.

  3. #3
    Quote Originally Posted by JAZZCNC View Post
    Edit: The drop bracket still needs some bracing thou.!! or a redesign of the whole thing.!.
    Hey, so I've decided to go back to my existing design of the gantry to Y ballscrew connection which was 10mm steel plate welded and braced with 10mm triangular plate sections. After testing this arrangement on the Chinese screws for play, measured at the tool with my dial indicators I'm quite happy with it strength wise so I have redesigned the same arrangement to fit the new ball-screws. The current layout has between 0.02mm and 0.03mm of play which is largely coming from the ballscrew nuts themselves, you can feel a good bit of play by hand in the ball nuts when these are off the machine which does tighten up significantly when both screws are in the machine (weirdly), but I definitely got unlucky with these Chinese ball-screws compared to what others seem to get. There's noticeable bends in them too so out they go. Bare in mind the current ballscrews are running with angular contact bearings in the BK12 holders, which I bought after the fact, so those bearings tighten up the play in the Y. Initially play was in the order of 0.1mm+ in my measurements before and fitting angular contact bearings. I can't feel any play at all by hand in the new ground ball-screws so I'm confident they'll be a big improvement.

    One catch with the new design is that I'll need to machine a ball-screw nut mount for the new ball-screw, one each side. Would anyone here be able to machine this part for me (x2) out of Aluminium for payment? I'd rather spread work here than a bureau service if anyone is free/able/willing.

    I don't think my Momus will be accurate enough to do it to this depth to be honest, there's just too much play in the Z (part is roughly 57mm x 65mm x 70mm from Ali (6061/6082 etc))

    Failing that I'll have to consider milling it in thinner 25mm sections bolted together until I can machine it myself from a single piece when the machine is in situ, but I'd rather get it done right the first time if possible.

    I still need to consider the bracing of the gantry to the Y bearing block plates, but I'm happy enough I can do that after the fact pretty simply and am considering an adjustable design there.

    I'm leaning towards setting this up in the standard horizontal arrangement atm, reason being I'm thinking of running high flow flood coolant on it and it's easier to manage that way.
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    Last edited by Evengravy; 17-06-2020 at 02:22 PM.

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