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JGAURORA JGMaker Magic Promotion


NEW Budget 3D Printer: JGMaker Magic
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JGAURORA A5S Deals


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Upgrade bearings for x and y axis

2

Comments

  • ufodoctor3ufodoctor3 Posts: 60🌟 Super Member 🌟
    Hello Forum
    There were some errors in my recent report “X-Bearing Test with experimental results”.
    Sorry!
    Fig. 4: The Mechanical Force Sensor is for the range 0 to 20 N
    Fig. 7: At full current of 0.5 A the maximum force at blocking is 16 N
    Fig. 8: At reduced current of 0.34 A the maximum force at blocking is 8 N
    
    When I looked at again the long replacement x-bearing JGaurora on a precise test rod.
    Fresh from factory the friction was about 0.5 N and there was noise by the little moving
    spheres. With perfect cleaning and lubrication the friction is less than 0.2 N and 
    much less noise.
    Regards
    Peter
    
    Thanked by 1Samuel Pinches
  • Samuel PinchesSamuel Pinches Posts: 2,060Administrator
    Thanks for the detailed report Peter! I’m looking forward to reading it on the weekend.
    Thanked by 1ufodoctor3
  • ufodoctor3ufodoctor3 Posts: 60🌟 Super Member 🌟
    Dear Forum, especially to Sam and Der_Muck 
    Here you see the attachment my improved report about x-bearing friction test.
     
    I hope that I am not ”barking below the wrong tree”, else give me your competent advice,
    thank you!
    Regards
    Peter

  • Der_MuckDer_Muck Posts: 265🌟 Super Member 🌟
    I cant understand that, I think you only have bad bearings on the X axes, my X axes is so smoth and I nearly clean the rods not at all. 
    I had about 6 bearings and I took the best of them. Some where to easy to move for my taste and some where to stiff.
    Rattling can also come from the X motor itself. It sounds like it is one bearing what is rattling but its the motor. Try to decrease the speed. Higher the hybrid threshold speed up to 120 if you have TMC2130 decrease the acceleration a little.   I had a rattling effect with the auto bed leveling of the bl touch. Now its gone, I just set the leveling a bit slower.

    Thanked by 1ufodoctor3
  • ufodoctor3ufodoctor3 Posts: 60🌟 Super Member 🌟
    Dear Der_Muck
    Thank you!
    You are right with your comment, that the rattle noise is generated by the x-stepper motor! 
    The rattle appears if the x-bearing shows to much friction or if I add counter-force
    with my spring force sensor up to 16 N during testing 10 mm x-steps
    
    What I cannot understand is the fact, that the replacement x-bearing, fresh from factory, 
    was quite stiff (0.5N) on a precise 8 +0/-0.002mm rod, with noise coming from 
    the internal moving spheres. But now, after some manipulation and lubricated, 
    the x-bearing moves easily at already 0.1 N, and very silent
    
    Software is easy, hardware is hard!
    Best Regards
    Peter

  • ufodoctor3ufodoctor3 Posts: 60🌟 Super Member 🌟
    Understanding the x-bearing friction problem

    Dear Der_Muck

    Please check my following statements about the x-bearing rattle problem:

    1. The stepper motor is equipped with 4 coils, 2 vertical and 2 horizontal

    2. The vertical coils are connected in series (for maximum torque) at terminal E1+ and E1-

    and the horizontal coils are in series at terminal E2+ and E2-

    3. Giving + and – current pulses at these terminals (by the Move x-Command), the stepper motor will perform a series of steps,

    forward and backwards if no excessive x-counter forces are present.

    4. The current into these coils are independent of the x-counter force or mass acceleration, no electronic monitoring method possible

    for checking the executed steps.

    5. If the counter force is too strong (friction in the x-bearing or by our applied spring force sensor, max up to blocking),

    the steps cannot be completed and the stepper motor shows a loud rattle noise

    6.With reduced current supply by our friction tester we can investigate, if the steps are completed also with 1/2 current pulses.

    Situation A: If you do not hear any rattle, the x-system is perfect for the next printing job

    Situation B: If you hear any rattle, the x-bearing needs to be cleaned and the rods needs to be cleaned and lubricated!

    OK? If not, I am still barking below the wrong tree!

    Kind regards

    Peter


  • ufodoctor3ufodoctor3 Posts: 60🌟 Super Member 🌟
    Dear Forum
    The 3rd attachment below presents my recent calculations on x-Friction/Rattle problem with more 
    detailed experimental results for the JGaurora 5 printer
    
    If my approximative calculations are correct, the maximum force of the x-Stepper Motor is very clos to the minimum required x-forces for proper 3D-Prining.
    
    Here my simple advice after very long investigations:
    
    If you notice “x-motion rattle”, please check three things:
    1. Clean the entry of the the upper x-bearing.
    2. Clean the rods and lubricate both by a thin PTFE or other thin spray 
    3. Reduce the Print Speed and Travel Speed to about 50 mm/sec
    
    The x-stepper motor will be happy now!
    
    Best regards
    Peter
    

  • ufodoctor3ufodoctor3 Posts: 60🌟 Super Member 🌟
  • Samuel PinchesSamuel Pinches Posts: 2,060Administrator
    Thanks for your investigation Peter. I think it is sadly a bit common for cheap bearings to be full of dirt and also machining residue particles.
    Thanked by 1ufodoctor3
  • ufodoctor3ufodoctor3 Posts: 60🌟 Super Member 🌟
    Dear Sam
    Thank you for your comment!
    We cannot expect a perfect performance of a cheap system with stepper motors without
    position feedback.
    But with my proposed early warning friction test system you will know, 
    if the friction is within acceptable limits or needs cleaning and lubrication.
    
    Did you see my post about ABS slurry? Many problems of ABS adhesion to the bed and crack
    repair can be solved easaly.
    
    Kind regards
    Peter

  • ufodoctor3ufodoctor3 Posts: 60🌟 Super Member 🌟

    Still x-Offset Problems at variable heights 5 to 15 mm during printing

    Dear Team
    With perfect  cleaning  and lubrication of the x-rods I noticed loss of the x-stepper Motor track and x-Offset of the upper printing layer

    The x-slider moves fine with only litte friction < 2 N. The x-stepper Motor delievers a force of 16 N during x-step test 
    What is wrong?

    Do you have ideas how to prevent x-Offset?
    Best regards
    Peter

  • Samuel PinchesSamuel Pinches Posts: 2,060Administrator
    Hi Peter, I’m sorry to hear that you’re still having problems with the x axis. 😔
    Can you please check the cables are all firmly inserted for the motors, and that if you wiggle the cables during printing, that no abnormal behaviour occurs?

    Also, what print speed are you using? Is this using the community 1.1.8 firmware?
    kind regards,
    Sam
  • Der_MuckDer_Muck Posts: 265🌟 Super Member 🌟
    @ufodoctor3
    As you report friction problems, I changed last week my X stepper motor to a high quality one. 
    (its passible to do that without disassambling anything, that was pritty cool)
    So  I remember your problems and checked only because it was interesting for me, my printers X friction.
    So I can report to you, thers no friction at all. With loose belt, the X axes moves very very smoth. 

    So if you have friction there (without motor) you may have bend axle rods or your linear bearings are very very bad.

    How is your motor temp. when you loose steps? How is your currant setting for the extruder? Do you have SPI?
  • ufodoctor3ufodoctor3 Posts: 60🌟 Super Member 🌟

    Dear Sam
    I have lost the direct contact to my Forum Name "ufodoctor3". I had to create a new Forum Name "Peter3".

    My last blog appeared under "Peter3", can you transfer it to "ufodoctor3" and delete "Peter3"?

    Many thanks!

    I have revised my report “x-axis rods tuning parallel by clamps”

    It is now on my homepage http://ufo-doctor.ch/?select=3D%20Printer


    This new report shows more details and proves the fact, that non-parallel x-axis provide an overload of the axial bearing of the slider, leading to rattle, friction and x-offset.


    Best Regards

    Peter



  • ufodoctor3ufodoctor3 Posts: 60🌟 Super Member 🌟

    Dear Sam

    Thank you very much for your advice! In a second trial the ”gear” apeared and I could sign out and sign in following your prescription 

    Now I am ufodoctor3 again THANK YOU VERY MUCH

    AndI shall  try now to update my recent posts:


    X-axis rods tuning by clamps preventing x-offset with less friction

    Dear members

    I observed many times an x-offset, with well cleaned and lubricated x-axis rods!

    Finally my wife and I have observed that the x-rods are not parallel.

    With two clamps, manufactured by ABS 3D-printing, this problem is solved now by tuning the x-rods parallel within 0.01 mm.

    Please look at the attached report and STL-file (Needs 3 coffes for uploading!)

    Kind regards

    Peter


    Thanked by 1Samuel Pinches
  • ufodoctor3ufodoctor3 Posts: 60🌟 Super Member 🌟
    Sorry, I have sent the GCode for direct 3D-Production, but now you see the STL file  in the attachment. 
    Best regards
    Peter (ufodoctor3)
    Thanked by 1Samuel Pinches
  • Der_MuckDer_Muck Posts: 265🌟 Super Member 🌟
    One thing improtant, never ever share or use a gcode you didnt produce or wrote yourself.
    It can distroy your machine or effect the machine.   Your system or other systems are maybe a lightly different than others and that can have a realy realy bad effect.    For example, my gcodes would distroy your machine for sure.

    For save handling, STL model with own sliced gcode is save to use. Only to keep in mind :)
    Thanked by 1ufodoctor3
  • ufodoctor3ufodoctor3 Posts: 60🌟 Super Member 🌟
    Dear Der_Muck
    Thank you for this important advice!
    Best regards
    Peter
  • ufodoctor3ufodoctor3 Posts: 60🌟 Super Member 🌟

    Dear Members

    With my ABS-clamps the two x-rods become parallel, no more x-offset and rattle!

    But looking at the video by DaHai:

    https://www.bing.com/videos/search?q=The+Unofficial+JGAurora+3D+Printer+Forum+&view=detail&mid=9227F6F1DB284026F6D69227F6F1DB284026F6D6&FORM=VIRE

    it becomes clear now, why the rattle problem was NOT noticed with an older JGaurora5:

    The old original was equipped with an ALUMINIUM clamp for the two x-rods, precise and temperature stable.

    My JGauoura5, purchased Oct 2018, is equipped with a PLASTIC x-axis clamp, (greatly improved for low price, but far away from mechanical reliability)

    Let us hope, that the announced new JGaurora5 is better designed, back to the roots!

    Best technical regards

    Peter


  • Der_MuckDer_Muck Posts: 265🌟 Super Member 🌟
    Sorry to say that but I only know you haveing that problem. My X head moves without a problem, maybe your X guides are lightly bend, maybe you want to check them. There are some linear bearing which a tighter than others (as said before) even they are from the same company. I used the freest one out of a bunch I ordered, knowing the fact they have a lightly higher tolerance and it just work and I also have the plastic X clamps.
    Usually X rattling comes with wrong settings of the hybrid threshold speed and the max speed of a axes by using the TCMs but that is easy to find out. 
    Maybe the russian solving way by bending the guides in the right position is a lighter way to solve the problem :D Sometimes force and measurement is the best way hehe
    Thanked by 1ufodoctor3
  • ufodoctor3ufodoctor3 Posts: 60🌟 Super Member 🌟

    Dear Der_Muck

    Of course, we cannot expect Swiss Quality from the cheap Chinese D8 rods. But in my case the left PLASIC clamp was deformed, with an axial distance error to the left of +0.4mm. This is too much!

    After adjusing the axial distance to 35 +/-0.02 mm with my clamps, the original axial ball bearing are working now with minor friction and are silent!


    I unerstand your russian way to hammer onto the rods to get less rod-bent, but this is brutal. Much better would be to understand the axial distance problem of the present suboptimal original PLASTIC rod clamps and corrected it carefully by precise additional

    clamps!


    Kind regards

    Peter


  • ufodoctor3ufodoctor3 Posts: 60🌟 Super Member 🌟

    Dear Members

    For ABS printing the JGaurora5 must be protected against air flow from all sides perfectly!

    No minor air slit is allowed, and the top plate is intended to prevents chimney effects.

    Check it with artificial smoke or with the steam of a low cost ultrasound humidifier.

    In the picture below you see my transparent cub, made by 3 mm acrylic plates (about 600x600x600 mm), mounted into a frame of alu-tubes D6/4 and PLA-edge connectors.

    The front side shows below a flexible lid for the bed moving in +y-direction during leveling

    And Below you see some some useful chemicals and tools.

    If you are interested, I am pleased to send more info's with STL files about the edge connectors and plate holders!

    Best regards

    Peter


  • ufodoctor3ufodoctor3 Posts: 60🌟 Super Member 🌟
    edited June 23
    And hee is my attachment


    Post edited by Samuel Pinches on
  • ufodoctor3ufodoctor3 Posts: 60🌟 Super Member 🌟

    Dear Sam

    Thank you very much for editing my posts! I am good in mechanics and electronics, but sometimes I do not find the correct tap on my PC or are not patient enough for the upload of my attachments!


    Also many thanks to Der_Muck with his useful advice!


    But now back now to the x-bearing friction problem:


    I feel that many of us (inclusive me) are sometimes “barking below the wrong tree, as we say in German”


    I understand that the axial JGaurora bearings are suboptimal. If they are not overloaded by radial force (in my case: 30 N, due to non-parallel x-rods) they operate quite well.


    But can a normal JGaurora user check the parallel distance of the two x-rods 35 mm within 0.01 mm accuracy?


    So my advice for all users with x-offset and rattle problem: check the x-rods distance with a self made 27 mm+/-0.01 gauge, as good as you can.


    If the axial distance at the left side is not ok, apply my clamp proposal, if you like it.


    And please inform the JGaurora company to add an aluminum clamp for axial long term stabilization, as they did it before in the beginning!


    Kind mechanical regards

    Peter



  • Der_MuckDer_Muck Posts: 265🌟 Super Member 🌟
    I realy dont think JG would change anything on the A5 because its a mass produced printer which they made cheaper now and is to long on the market now. 
    In the beginning they simply had no company (or the money) which made there plastic injected parts so they used aluminium milled and printed parts. Now they have it and can produce much much cheaper.
    Its simply the wrong price section, a 280€ printer is always a compromise.

    Maybe you ask JG for a replacement and all is ok.

     
    Thanked by 1ufodoctor3
  • ufodoctor3ufodoctor3 Posts: 60🌟 Super Member 🌟

    Dear Der_Muck

    Thank you for your info about the JGaurora history. It was really a suboptimal (stupid) idea to manufacture the left x-rod holder by plastic injection!

    With my rod-clamps, correcting the rods parallel exactly to 35 +/-0.01 mm, my long-lasting problem about rattle and x-offset are solved now, even with the suboptimal original JGaurora bearings.


    Without my ABS clamps (with internal steel M3 clamps), the original non-parallel 35 +/- 0.4 mm rods are bent by the stiff x-slider, with radial forces up to 30 N, radial overloading the bearings and provoke irregular axial friction!

    If you intend to design by your own an almost perfect 3D-Printer: give me please your proposals about Hard/Software!

    Or can you propose me an already existing better 3D-Printer in the 500 USD range?

    Best regards

    Peter


  • Der_MuckDer_Muck Posts: 265🌟 Super Member 🌟
    Even with a Ultimaker you will have some problems. Even our Austrian Evotech in the company has very very big problems. Its nearly impossible to print PLA with it, it simply has do fanduct at all, how stupid engineering is that :disappointed:

    So its all about tuning the printer in that direction where you want to have it. A standard JG A5 is a solid printer out of the box. Due the fact its a very low priced printer, it prints very very well for the price but ofcause it always can be that you got a monday made printer. 

    For example, my printer only has only maybe 1/2 of the original parts left, even less. But now I can even print ultem (ok maybe for that I must tune the bed a bit more) but you understand what I mean. 

    If you want a printer all in one out of the box, your price for a good printer maybe beginns between 5000 to 10000€ and up. 
    I calculated a costume printer of mine with a material cost about 2000€ and those are no high precision elements. I didnt even think of them because maybe the costs would be doubled minimum.
    So I stopped that project because it is unsure to reach a much better quality than my JG now reaches.
    Thers simply no need for such costs and end quality of the print. That is why chinese printer are that successfull, cheap, mass produced and can print very well for the price.
    If you want 0,01 precise prints, go for a SLA or a SLM printer. No chance with a filament printer to reach such a precision.
  • ufodoctor3ufodoctor3 Posts: 60🌟 Super Member 🌟

    Dear Der_Muck

    I apreciate very much your comments, since you and I are “perfectionalists”, making the inpossible possible with a lot of care but with little money!


    But I fear that we bore to death the JGaurora Forum members by our discussion! They want learn simple answers to very difficult questions!.


    So my proposal: get in private contact to me by email pan.neukomm@bluewin.ch.

    and we can discute technical details without disturbing the forum!

    You are free to communicate a summmary of our discussion in the forum!


    Kind regards

    Peter


  • Samuel PinchesSamuel Pinches Posts: 2,060Administrator
    edited June 24
    I enjoy reading it! :smiley: Great discussions. You are both on the chat too if that is easier :smile:
    Thanked by 1ufodoctor3
    Post edited by Samuel Pinches on
  • ufodoctor3ufodoctor3 Posts: 60🌟 Super Member 🌟

    Dear Der_Muck and Sam

    Would you please so kind to measure the axial distance of the two x-rods at YOUR JGaurora5 3D printer?

    If the left/right is 35 +/- 0.1 mm, I have to admit that I got Oct 2018 a “Monday Morning Printer” with 35.4 and 35.0 values and should ask for a replacement by the manufacturer, stopping “barking below the wrong tree”


    Kind measuring greetings

    Peter



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