Problem with New middle Assembly (bearing contact and squareness)

New Home Forum Mostly Printed CNC – MPCNC Troubleshooting – MPCNC Problem with New middle Assembly (bearing contact and squareness)

This topic contains 25 replies, has 2 voices, and was last updated by Profile photo of Levi Blaney Levi Blaney 1 year, 1 month ago.

Viewing 26 posts - 1 through 26 (of 26 total)
  • Author
    Posts
  • #13601
    Profile photo of Levi Blaney
    Levi Blaney
    Participant

    Hey,

    This is my first MPCNC. Everything was going fine until I got to the middle assembly. The 5 in bolt that runs though the middle of it was an incredibly tight fit. I had to use some C clambs to make a press to press it though all the parts. Then when it came time to insert my conduit the bearings on the front side (tool mount side) of the x and y blocks made contact just fine but not the back bearings (the side where you check for square). The only way I can get the back bearings to make contact is by really cranking down on that 5 inch bolt. When I do that I always end up at 91 or 92 degrees (out of square) and then the all thread going down though the Z feels really tight. It’s hard to turn by hand with the pineapple adapter. I fooled with it for about 3 hours and can’t figure it out. Any one have a solution? My parts were bought here.

    Thanks,
    Levi

    #13602
    Profile photo of Ryan
    Ryan
    Keymaster

    Put up some pics so we can look for any obvious errors in assembly.

    You bought the plastic from here or just the hardware?

    #13603
    Profile photo of Levi Blaney
    Levi Blaney
    Participant

    I bought the entire bundle here. Printed parts, Hardware and Electronics. Is that 5 inch bolt supposed to be so tight? It really surprised me compared to the perfect fit all the other parts had. It was tight over the threads themselves and then it gets bigger over the smooth shaft. Thats why I had to use the clamps to act like a press. Until I tighten that 5 inch bolt really tight there is lots of slop between the conduit and bearings in the back. Pictures coming up in the next 30 mins. Also the all thread came with 2 nuts and a spring but I couldn’t find instructions for what to do with them.

    Thanks,
    Levi

    #13605
    Profile photo of Ryan
    Ryan
    Keymaster

    The extra parts go with the old parts. You don’t need them. The bolts should be tight but it also shouldn’t be an issue. Did you get the 23.5mm parts or the 25mm? What size conduit do you have, there should be no slop before that bolt goes in. It is actually a slight (.2mm ish) interference fit.

    Did you put it together in the order of operations in the instructions?

    #13606
    Profile photo of Levi Blaney
    Levi Blaney
    Participant

    The order history says 23.5 , the emt I bought from the local hardware store it just says 3/4 inch ID EMT. I don’t have calipers to measure the parts I recieved or the conduit. I could get a pair though. I’m having trouble uploading pictures from my house because of slow Internet.

    #13607
    Profile photo of Levi Blaney
    Levi Blaney
    Participant

    Finally got the pictures and the short video to upload.

    https://goo.gl/photos/pQFARmYvUDHSPf3U6

    #13608
    Profile photo of Ryan
    Ryan
    Keymaster

    That leadscrew should not be out of place like that, It could just be the nut holder under it is out of alignment.

    Not sure what it could be. Are the 1.5″ bolts loose, they should be? If those are too tight you could be throwing it all out of wack. If the conduit fit in the front half there is no way the back half shouldn’t fit. You didn’t put the bearing spacers in there did you just bearings right? Tighten the 5″ bolt and it should take up the slack.

    I know the parts are good I just built 2 more machines and they fit great. I checked all the pieces on 4 more sets I have printed and the only part that has some friction to the 5″ bolt is the XYZ plate all the rest slid through by hand.

    #13609
    Profile photo of Levi Blaney
    Levi Blaney
    Participant

    I went over to take better photos but couldn’t really get what I wanted. Right now i have all torsion screws loose and I’m only get contact on 2 out of 3 bearing both front and back and left and right xy mount. Now if i tighten torsion A bolts the front 3 bearings come in contact nice and smoothe, but those back sets won’t unless I really crank down on torsion B (5 inch bolt). My z is perfectly fine and so are my motor mount assemblies.

    #13610
    Profile photo of Ryan
    Ryan
    Keymaster

    Spin your conduit it might be an oval. If that doesn’t help tightening the 5″ should be fine.

    #13611
    Profile photo of Levi Blaney
    Levi Blaney
    Participant

    None of the torsion bolts are tight, no bearing spacers. The back bearings will make contact if I really tighten that 5 inch bolt but that jams the lead screw and locks me at 92 degrees so I’m out of square.

    None of my center assembly slipped over that 5 inch bolt. They all had to be pressed on. Spacers and all.

    #13612
    Profile photo of Levi Blaney
    Levi Blaney
    Participant

    I took it completly apart, ill upload videos soon. I had to beat things apart with a hammer.

    #13613
    Profile photo of Ryan
    Ryan
    Keymaster

    You can very easily break things with a hammer, please be careful. If you have it apart it would be easy to just drill out the 5″ bolt holes with a 5/16 bit.

    #13614
    Profile photo of Levi Blaney
    Levi Blaney
    Participant

    You would be suprised how hard I had to to hit that 5 inch bolt to get it through the center assembly, speaking of which. Ill be ordering a new bolt if I can’t find one at the hard ware store. It’s a little bent.

    #13615
    Profile photo of Ryan
    Ryan
    Keymaster

    I usually just put pressure on it while turning and it kinda just un-threads out even when there is no threads.

    #13616
    Profile photo of Levi Blaney
    Levi Blaney
    Participant

    Idk. Those top and bottom gray brackets wouldn’t go from the threaded part to smoothe part at all, and the rest of the parts wouldn’t hand fit. Maybe it came a little bent. I tried for a while before I used the c clamp. I just hope a new bolt fixes it. I’ll look tomorrow at the hardware store or I’ll order it from you, no big deal.

    #13617
    Profile photo of Levi Blaney
    Levi Blaney
    Participant

    Thumb detector never fails

    https://goo.gl/photos/n7PZS6bY8Nq73FrE8

    #13641
    Profile photo of Levi Blaney
    Levi Blaney
    Participant

    I bought a new, almost identical 5 inch bolt this morning. I was able to get the assembly square, but in order to get all bearings touching in the back I had to really tighten that 5on bolt. Enough so that it warps the entire center assembly and it jams the lead screw. I will try another section of conduit from another store but I haven’t had any problems with the reast of the build.

    When I have that 5 inch bolt loose, in the back only 2 bearings are making contact with the conduit and the third has a 1mm or so gap.

    https://goo.gl/photos/5ukk3CJ63mMBJG9

    Edit: added 2 more pictures showing the gap

    #13650
    Profile photo of Ryan
    Ryan
    Keymaster

    It does not make sense. the large xy pieces are an interference fit and should flex open to fit the conduit without a bolt in it, and the 5″ bolt should do nothing to change the conduit angle. I have to assume your conduit is the wrong size.

    Of the pieces that didn’t fit smoothly here it was from print blobs on the inner surface. I chased the holes with a 516 drill bit and everything is smooth now. I will do this before I ship any more parts from now on.

    #13674
    Profile photo of Levi Blaney
    Levi Blaney
    Participant

    I didn’t get a chance to get new conduit today, but get a hold of me. I would like to know what the price would be to buy a new center assembly, printed parts only.

    I’m wondering if when I had that bent bolt in if I exerted to much force trying to get it square and tweaked the xy brackets.

    Thanks

    #13675
    Profile photo of Ryan
    Ryan
    Keymaster

    I don’t think you can really tweak them without cracks forming. I would just drill out the holes that the 5″ bolt passes through and give it a try. Verify that your conduit is the correct size as well. If anything it should be a tight fit, never heard of a loose fit. What letter is printed on the parts?

    #13679
    Profile photo of Levi Blaney
    Levi Blaney
    Participant

    Ill try with new conduit soon. I already drilled out the holes that the bolt passes through. The work around I’m using now is c clamps on the back of those xy brackets to keep tension on those bearings.

    I would rather order an extra center assembly then to get conduit and still not fix it. I didn’t Crack any of the parts but im pretty certain something is warped.

    Just let me know if I can order a new center, I would like to keep the ball rolling on this project.

    Edit: letter C

    #13681
    Profile photo of Ryan
    Ryan
    Keymaster

    What pieces do you want? The mail has already been picked up today. I can send you an invoice and ship tomorrow.

    #13682
    Profile photo of Levi Blaney
    Levi Blaney
    Participant

    The 2 gray z brackets, the 2 xy brackets, the spacer and the spacer with the nut capture for the lead screw that is sized for the all thread that comes in your usa version of the kit.

    #13808
    Profile photo of Levi Blaney
    Levi Blaney
    Participant

    Did you remember to ship that? I got new conduit and it’s a no go. I got a pair of calipers and when the new parts get here I’m going to compare them to the old. Soon as I get the new center I can wire up the steppers and get to learning how to 3d print. I went ahead and ordered a bunch of milling stuff too. I’m going to give fusion 360 a shot because I already model in it but I can’t find a way to make it do trochoidal milling. I know it has “adaptive 3d clearing” which is supposed to be better but it’s not what our machines need. That’s for Tormach machiness milling SS and stuff. I might get ESTLcam though. Its got that “tabs” feature which I can’t find in Fusion unless I model them =/

    #13821
    Profile photo of Ryan
    Ryan
    Keymaster

    Sorry I took Sunday off.

    I just answered your paypall dispute.

    #13826
    Profile photo of Levi Blaney
    Levi Blaney
    Participant

    Dont be sorry, hope you enjoyed it. I spent it tubing paint creek and ruined my phone.

Viewing 26 posts - 1 through 26 (of 26 total)

You must be logged in to reply to this topic.