3 point levelling bed need suggestion .



  • Hi all , I am modding my first old 3d printer trying to switch from 4 to 3 bed leveling system
    For structural reasons I have only two options0_1554368514019_bed.jpg

    I already made the second version but I have used the lonely point as reference and it wasn't work very well also, this config has the downside of losing about 30mm on the z axis.

    0_1554368649936_20190317_111128 (Small).jpg

    any suggestion?
    Thx
    Andrea



  • Either one of your configurations should work fine, but you've got the pitch and roll screws mislabeled. The easiest leveling is done by aligning the pitch and reference screws along one axis of the printer (your reference and roll screws). You adjust the pitch first then the roll.

    When you adjust one screw, the plate will tilt along a line drawn between the other two. If you adjust pitch first, when you adjust roll, it will have no effect on the pitch of the plate.



  • Yes I mislabeled, perfect thank you.
    I just ordered a 340x330 8mm pei covered aluminum bed.
    I will drill it by myself with my CNC so I will be able to find the best positioning.
    I saw your clever regulation system of your bed and I would like to copy it 🙂
    can you tell me the dimension of the balls and the grooves on the bed are you using .
    Maybe I will not make holes on the bed , and I 'll use underside regulation on all points do you think it will be possible with 8 mm thick plane?



  • @claustro I bought the ball head screws from amazon.com. They are commonly used in RC racing cars for some unknown (to me) purpose. IRIC, the heads are 10mm in diameter. Those screws have a hole in the ball for a hex key. The ball heads are hollow, and if you apply too much torque to the hex key you can strip out its socket. If you want to adjust from the underside of the bed, you can get something like the balls used in delta printer effectors. Something like this.

    A 300 mm bed only expands about 0.6 mm when heated to 100C, so the pitch adjuster slot has to be at least that long, but I made the slot about 3-4 mm long to allow for some slop in the placement of the leveling screw.

    It isn't really necessary to chamfer the hole and the slot, and in fact it isn't even necessary to drill a hole or cut a slot- they can be parts that you screw or epoxy to the plate and serve the same purpose (if you're going to be adjusting the screws from the underside of the bed anyway).



  • @mrehorstdmd

    @mrehorstdmd said in 3 point levelling bed need suggestion .:

    It isn't really necessary to chamfer the hole and the slot, and in fact it isn't even necessary to drill a hole or cut a slot- they can be parts that you screw or epoxy to the plate and serve the same purpose (if you're going to be adjusting the screws from the underside of the bed anyway).

    Good point!
    Also the bed I bought has PEI on both sides , using removable parts underneath allow me to flip it if needed.
    Are your ball screws M4?
    Hi had some ball screws laying around a little bigger M4 with heas around 14mm , I think it should fit. I am thinking about the best slot dimensione in relations to the head diameter. Using a glued extra part I can use a deeper groove of the 8mm permitted by the bed thickness even if maybe half diameter will be the best .
    I read a lot of your posts in many forum , very very useful thank you for reporting all your ideas and progress.



  • @claustro They are M5 screws. The hole and slot in the bed are about 4 mm diameter/width, and IRIC, the chamfers go about 1/2 way through the 8 mm thick plate in UMMD.


 

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