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Community Favorite Alternative to the Lead Screw Upgrade Kit

Discussion in 'Mods and Upgrades' started by WheresWaldo, Nov 23, 2015.

  1. Paladin

    Paladin New Member

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    I'm printing the adapters now, and ordered the same TR8*2 lead screws. Care to share your firmware numbers??
     
  2. WheresWaldo

    WheresWaldo Volunteer ( ͠° ͟ʖ ͡°)
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    @Paladin the only thing to change is the number of steps for the Z axis, in Configuration.h:
    Code:
    #define DEFAULT_AXIS_STEPS_PER_UNIT   { 80, 80, 1600, 800 }
     
  3. fastbike02

    fastbike02 New Member

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    I purchased these rods on ebay and wanted to ask if changing the steps to 1600 would work with the 2mm pitch of these?

    thanks in advance!
    Tr8 8mm Acme Lead Screw Trapezoidal
    • 300mm Long (11 - 13/16")
    • For 3D Printers and Smaller CNC builds
    • 2mm Pitch
    • 8mm Diameter
    • 4 Starts
    • (It moves 8mm per 360 degree revolution )
    • Fast Accurate Movement
    • Includes 1- 300mm long acme screw and 1 - Brass Nut
    • If you are using the common 1.8 degree stepper motor on 1/8 step mode
    • You would use 200 steps per mm
     
  4. WheresWaldo

    WheresWaldo Volunteer ( ͠° ͟ʖ ͡°)
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    No those are TR8*8 and the 3rd parameter of 1600 in the example above needs to be 400 instead.

    TR8*2 = 2 mm lift per full rotation you bought lead screws that are 8 mm lift per full rotation. If you are using the firmware I have pre-configured, the line is already there, just comment line #478 and uncomment line #480 in Configuration.h.
     
  5. fastbike02

    fastbike02 New Member

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    Well darn, how will these affect the quality of the print compared to tr8*2? and is the mesh firmware better than the v3
     
    #85 fastbike02, Apr 17, 2017
    Last edited: Apr 17, 2017
  6. WheresWaldo

    WheresWaldo Volunteer ( ͠° ͟ʖ ͡°)
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    Mostly correct, a TR8*8 would be 1/2 the Z resolution of an R1+, where a TR8*2 would give you double the resolution of an R1+

    Each revolution of the stepper motor has 200 steps, so :
    TR8*8 lead screws which you have will resolve to 0.04 mm lift per full step
    The R1+PLUS has integrated TR8*4 lead screws which will resolve 0.02 mm lift per full step
    TR8*2 lead screws will resolve 0.01 mm per full step
    What complicates this even more is that Marlin and your RAMPS board has something called micro-steps, It is an arbitrary division of each step into 16 divisions using a current divider. There is no guarantee of accuracy using micro-steps but it is close enough. You will be hard pressed to tell any difference in model details printed with similar layer heights on any of the three variety of lead screws.

    I say mostly correct in the first sentence because you really need to calibrate your extruder as the 723.38 parameter is something Robo pulled out of the air with no basis in reality. there are tons of posts all pointing to the same Thomas Sanladerer YouTube video on how to calibrate the extruder.
     
    mark tomlinson and fastbike02 like this.
  7. Paladin

    Paladin New Member

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    I finished the install today but haven't calibrated or printed anything yet. I wasn't sure about the movement I have in the lead screws. It seems that the only way I can get them not to 'wobble' is to only tighten one of the two set screws holding the lead screws in the couplers. I tried tightening one then the other at different rates but nothing seemed to result in them rotating smoothly.

    I uploaded the firmware with the new steps and although movement is working in all directions, I definitely see wobble. Any ideas? Is the wobble acceptable? Is one set screw enough to hold the lead screws in place? I'm afraid that they'd eventually work loose.

    Update:
    I printed a 20x20 calibration cube with both set screws installed. I forgot to put any grease on the lead screws but even without it the cube was the best of the 4 I have done since buying and upgrading this kickstarter model. I am quite happy so far!
     
    #87 Paladin, Apr 18, 2017
    Last edited: Apr 19, 2017
  8. Ssendam

    Ssendam New Member

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    Hey all, hoping to get some help here. I've just installed the lead screw upgrade using the following lead screws

    T&B T8 L300mm 8mm Lead 4 Start Acme Lead Screw and T Nuts for 3D Printer Z Axis

    I had a bit of a time getting them straight but I think I have that resolved now.

    Since it seemed like they were the same screws used in the tutorial, I set my steps to 1600 as suggested. EVerything levels correctly but my prints are starting about 10-15mm off the build plate so I feel like the numbers are wrong.

    This is the output of M501:
    Code:
    Send: M501
    Recv: echo:Hardcoded Default Settings Loaded
    Recv: echo:Steps per unit:
    Recv: echo: M92 X80.00 Y80.00 Z1600.00 E723.38
    Recv: echo:Maximum feedrates (mm/s):
    Recv: echo: M203 X500.00 Y500.00 Z5.00 E25.00
    Recv: echo:Maximum Acceleration (mm/s2):
    Recv: echo: M201 X9000 Y9000 Z100 E10000
    Recv: echo:Acceleration: S=acceleration, T=retract acceleration
    Recv: echo: M204 S500.00 T3000.00
    Recv: echo:Advanced variables: S=Min feedrate (mm/s), T=Min travel feedrate (mm/s), B=minimum segment time (ms), X=maximum XY jerk (mm/s), Z=maximum Z jerk (mm/s), E=maximum E jerk (mm/s)Recv: echo: M205 S0.00 T0.00 B20000 X17.00 Z0.40 E5.00
    Recv: echo:Home offset (mm):Recv: echo: M206 X0.00 Y0.00 Z0.00
    Recv: echo:PID settings:Recv: echo: M301 P22.20 I1.08 D114.00
    So it seems the firmware modification worked. I think put my calipers on the build place and the z axis at about 50mm. I ran G1 Z10 F1200 and the calipers said it moved up to around 90mm. So its still WAY off lol.

    Any ideas what could be wrong? I tried looking at the prusia step calculator but I don't know the other variables to use. Any help would be greatly appreciated!
     
  9. WheresWaldo

    WheresWaldo Volunteer ( ͠° ͟ʖ ͡°)
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    TR8*4 should not be 1600
    TR8*4 = 800 steps
     
  10. Ssendam

    Ssendam New Member

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    I changed it to 800 and measured the same command, it gave me 20mm of up travel. Tried 400 and it seems to be accurate now. Thoughts?
     
  11. danzca6

    danzca6 Well-Known Member

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    Then you must have TR8*8 leadscrews
     
  12. Ssendam

    Ssendam New Member

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    I guess so! Haha

    I did a calibration cube and all sizes were within 0.05mm of the expected size. Thanks for the help in the right direction!
     
    mark tomlinson likes this.
  13. danzca6

    danzca6 Well-Known Member

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    BTW, what method(s) did you use to straighten out the leadscrews? I know that was an issue with many in the first batches from Robo.
     
  14. Ssendam

    Ssendam New Member

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    It was mostly trial and error. I think the last thing I tried was seating the collet on the motor shaft first and tightening each side evenly (like a christmas tree) until it was tight. Then getting the lead screws in the collet, putting the top of my printer back on with the stabilizers in place and just loosened and tightened until I could get the screw spinning as straight as I could tell. It was a painstaking process and I don't think they are perfect but its the best I could do and my prints are way better than before.
     
  15. Domenic

    Domenic Member

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    So I am attempting this upgrade to fix my z banding. I order two 300mm lead screws from banggood but they are shorter than the ones that are in the printer currently. Will this affect my print volume significantly? Does anyone have a link to a good integrated lead screw motor that I could think about purchasing?
     
  16. mark tomlinson

    mark tomlinson ༼ つ ◕_ ◕ ༽つ
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    [QUOTE="Domenic, post: 130472, member: 14703"but they are shorter than the ones that are in the printer currently. Will this affect my print volume significantly? [/QUOTE]

    Depends on how much shorter. If they are a dozen mm or so shorter -- not really. If they are short enough to impact the build volume then sure (the Z rods are taller than the actual print volume by a bit if you print with the cover on).
     
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  17. Domenic

    Domenic Member

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    So while trying to switch out my lead screws from my R1+ I stripped the motor magnet a little bit. I was looking at replacing both lead screws all together from novice expert’s video. Could these two work and which one would you recommend?
    http://www.mpja.com/mobile/Step-Motor-with-300mm-T8-Leadscrew-for-3D-Printer/productinfo/35340+MI/

    http://www.mpja.com/mobile/Step-Motor-with-300mm-T8-Leadscrew-for-3D-Printer/productinfo/33515+MI/

    Or any of these:
    http://www.amazon.com/registry/wishlist/3L9JRD81E8TZ4
     
    #97 Domenic, Nov 18, 2018
    Last edited: Nov 18, 2018
  18. WheresWaldo

    WheresWaldo Volunteer ( ͠° ͟ʖ ͡°)
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    @Domenic
    All would work, these are all TR8*8 lead screws so the number of steps should be 400
     
  19. Domenic

    Domenic Member

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    Would anyone recommend using couplers and lead screws instead of integrated lead screws. So that if they were to bend again I would just have to replace the lead screw.
     
  20. mark tomlinson

    mark tomlinson ༼ つ ◕_ ◕ ༽つ
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    Nope, not really. That is what lead to the R1 (not the R1+) having banding issues :)
     
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