z thread nutlock again (old, original version)

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This topic contains 14 replies, has 2 voices, and was last updated by Profile photo of Ulli Ulli 1 year, 1 month ago.

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  • #12710
    Profile photo of Ulli
    Ulli
    Participant

    Hi all,
    finally I am finding some time again to work on on my machine. Basically, it’s just drawing in some cables and a few touches here and there. Just discovered the forum thread on the new center assembly, but having printed all parts, specially also toolholders for the Makita router and others, I’ll start workin with the oldschool version.

    And here is my question: I just cut the z-thread rod to length. I have a long coupler nut (M8), and some springs that are all pretty stiff and pretty long. Now, if I put it all together and compress the spring just so far that there is still no realizable increase in friction, the set is too long for the nut lock, it wouldn’t even hold the bottom nut.
    Would it make much difference to use just two ordinary nuts, separated by the shortest effective spring I can select here? Shortening the working thread length between nut and rod would simultaneously reduce the friction, I guess, due to the smaller surface area involved. Or am I wrong there?

    So, to boil it down: Should I rather

    [ ] look for a very short spring and use the long coupler nut and a short one,
    or
    [ ] combine two short nuts with an existing spring?

    Thanks for your advice!

    Cheers

    Ulli

    #12713
    Profile photo of Ryan
    Ryan
    Keymaster

    Just get rid of the spring, turns out it seem to do anything. I didn’t include it on the new parts.

    #12721
    Profile photo of Ulli
    Ulli
    Participant

    Thanks. So, just the long nut! ?

    #12722
    Profile photo of Ryan
    Ryan
    Keymaster

    Yup

    #12755
    Profile photo of Ulli
    Ulli
    Participant

    Thanks, Ryan.
    After trying to mount the z-nutlock in the completely mounted middle section, I disassembled it tonight and then could attach the nutlock pretty easily. After that, however, I discovered that the z-thread rod collides with the neighbouring bolt heads. Hope I get the pictures I just took of that in here.

    #12760
    Profile photo of Ulli
    Ulli
    Participant
    #12763
    Profile photo of Ryan
    Ryan
    Keymaster

    What size leadscrew is that? Is it in at an angle? it must be if it clears the top bolts but not the bottom. With an 8mm leadscrew/allthread, it is close 2mm clearance so if you went bigger you will need to do some grinding of the bolt heads.

    #12773
    Profile photo of Ulli
    Ulli
    Participant

    M8 – and it touches the bottom screws as well.

    #12775
    Profile photo of Ulli
    Ulli
    Participant

    Just measured the height of the heads: 5.90mm max from the transition from the shaft to the top of the inscripts.

    #12790
    Profile photo of Ulli
    Ulli
    Participant

    JFTR, I just spotted a small discrepancy between the photos and the drawing of the (old) middle array.
    Next to <http://www.vicious1.com/wp-content/uploads/2015/07/IMG_20150719_1230131.jpg&gt;, you say, ‘Both Heads Facing up.’, consistent with the photos.
    In the drawing in <http://www.vicious1.com/wp-content/uploads/2015/07/middle.png&gt;, one bolt is shown head up, the other with its head on the bottom side. Probably functionally equivalent.
    Is there any trick of loosening and re-fastening the parts of the middle section to maybe get rid of that misfit thread position? Of course, I could grind off some material of the bolt heads, but will the z-stepper drive assembly still fit and match?
    You say there should be 2mm clearance between the M8 rod and the bolt heads next to the nut lock? No way here. I must have introduced a systematic error when assembling the parts. But where and what?

    #12792
    Profile photo of Ryan
    Ryan
    Keymaster

    The both heads up thing is purely cosmetic. As for your rid not fitting I have no idea why. My best suggestion is maybe a small washer behind your but lock to push it out to where it should be. If the rest is square there is no reason this should be wrong. I haven’t seen this problem in a long time and they just put a washer and called it a day. Should not introduce a noticeable error.

    #12795
    Profile photo of Ulli
    Ulli
    Participant

    OK, thanks. I’ll figure out something like a thin aluminium plate or so. A one millimeter offset should do.

    BTW, regarding the nuts on the small screws holding the nut lock: It is really a challenge to place those correctly, specially when you have to diss- and re-assemble the whole caboodle. Proposal for future, comparable situations: Make a very tight-fitting nut-shaped recess in the carrying part and fixate the nut with a short touch of a soldering iron. To optimize that technique, heat up the iron first.

    One step closer again. Fine.

    Thanks again.

    #12796
    Profile photo of Ryan
    Ryan
    Keymaster

    completely got rid of that on the new parts

    #12797
    Profile photo of Ulli
    Ulli
    Participant

    I saw that, yes. My next machine then…

    #12839
    Profile photo of Ulli
    Ulli
    Participant

    Added a printed 1mm distance plate, nice match now. I think the reason for the offset is to be found in the slicer program. The holder for the nut lock is an oblique plane forming an overhang, and I suspect that the plate was printed a tad too wee, as they say in Scotland, or just too thin.

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