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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. DobryG

    DobryG Member

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    not steps sorry, the angle of rotation of the screw
     
  2. WheresWaldo

    WheresWaldo Volunteer ( ͠° ͟ʖ ͡°)
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    I use the same sized lead screw and have no issues printing at layer heights of 0.1 mm. The lead screw won't be your limiting factor. Still to move up 0.1 mm does require 40 steps of the stepper motor.

    You will have a very hard time finding a stand alone lead screw that is TR8-4
     
  3. DobryG

    DobryG Member

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    40steps per 0,1
    So it's not ballscrew and it wobbles a little in the nut..

    Seems not goot even for 0,1 accuracy, or enough?
     
  4. WheresWaldo

    WheresWaldo Volunteer ( ͠° ͟ʖ ͡°)
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    I cannot answer the question if it is accurate enough for you. It is for me. Also these are not ball screws they are lead screws. Ball screws have a lot less backlash and are more precise that lead screws. The weight of the X Axis should remediate some of the wobble.

    Here is an example of a ball screw that would fit the Robo, with modifications of course.
    http://www.ebay.com/itm/TBI-8mm-Min...345560?hash=item3d299fd498:g:X70AAOSw3mpXHyeY
     
  5. Zen

    Zen Member

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    So just tried this and funny thing my left side is sticking just like the video described even with the later model and printing in nylon. I am thinking that maybe some of the molds may have been off or slightly out of spec. bring out the sander
     
  6. Zen

    Zen Member

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    How did you get the lead screw centered in the coupling? I am thinking that my lead screws may be bent as I see wobble in the prints and wobble at the top of the lead screws when changing Z axis height. results in no Z banding, but waves in the walls of my prints as the two lead screws move from off center.
    Any ideas what to check or things to calibrate?
    Thanks
     
  7. WheresWaldo

    WheresWaldo Volunteer ( ͠° ͟ʖ ͡°)
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    The wave should not matter unless it is severe. You could test this yourself by restricting the movement (do not make this a solid connection) at the top of the lead screws. I am pretty confident that is the movement isn't severe you will see no difference in the resulting prints. Experiment some by slowing printing down by a third and I bet your waves will go away.
     
  8. Zen

    Zen Member

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    yeah, severe is an understatement on the wave. I could hang 10 on a short board. Ideas?
    Bent lead screws?
     
  9. WheresWaldo

    WheresWaldo Volunteer ( ͠° ͟ʖ ͡°)
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    Possibly, only real way to tell is to remove them and roll them across a piece of glass to see if they are warped. It could also be the way they are seated in the couplers.
     
  10. Zen

    Zen Member

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    Never underestimate the power of stupidity or tired in my case.o_O It helps if you put the cover on the right way....
     
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  11. mamejay

    mamejay Member

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    Just ordered all the parts for this upgrade. In the opinion of people who have performed this upgrade how have you found it? Can't wait to see the results.
     
  12. WheresWaldo

    WheresWaldo Volunteer ( ͠° ͟ʖ ͡°)
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    I can tell you that it brought up the level of printing to post R1+PLUS levels (but I have other upgrades too) and perimeters as well as layers are much more precise and even. But, remember I have a bias for this upgrade.

    The best part was that this cost me about 1/4 of the Robo official upgrade.
     
  13. mamejay

    mamejay Member

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    Perfect. I managed to get all upgrades for $18 aud. Love a cheap upgrade.
     
  14. sebrobin

    sebrobin Member

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    Hi,

    I'm about to perform this change. Do you need to upload the metric firmware or only change this value even if you have the imperial firmware ?

    Code:
    #define DEFAULT_AXIS_STEPS_PER_UNIT {80,80,2560,723.38}
    and change the third parameter (2560) to so that it reads as follows
    Code:
    #define DEFAULT_AXIS_STEPS_PER_UNIT {80,80,400,723.38}


    Not sure I understand which lead screw I have to purchase, any help ?
     
    #74 sebrobin, Jan 28, 2017
    Last edited: Jan 28, 2017
  15. WheresWaldo

    WheresWaldo Volunteer ( ͠° ͟ʖ ͡°)
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    The value is the only line that needs to change, the only difference between the old imperial 5/16" threaded rods or the metric 8 mm threaded rods in all versions of Robo firmware is that third parameter in that single line. So in other words, use whatever firmware you have and just change the line, recompile and re-upload it to your Robo.
     
  16. sebrobin

    sebrobin Member

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    thank you
     
  17. WheresWaldo

    WheresWaldo Volunteer ( ͠° ͟ʖ ͡°)
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    New Update:

    I found some cheap TR8*2 lead screws at Banggood.com.I have ordered a pair for myself. If you are going to do a lead screw upgrade why not make it better than the Official Robo Upgrade. TR8*2 will have a step resolution of 0.01 mm per step, the Robo upgrade is 0.02 mm per step and the original instructions here using a TR8*8 was 0.04 mm per step. This will give you finer control over the Z height. I will update the first post with the new lead screws.

    Also posted a link in message 2 for new couplers. Both are lower cost than the original links. Now the cost for parts has dropped from over $25.00 to a few pennies over $13.00. At that cost this should be a no brainer update.

    As soon as mine arrive (should be just about two weeks) I will install the new lead screws and report back.
     
    #77 WheresWaldo, Feb 26, 2017
    Last edited: Feb 26, 2017
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  18. WheresWaldo

    WheresWaldo Volunteer ( ͠° ͟ʖ ͡°)
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    [​IMG]These are about to be installed in place of the TR8*8 lead screws. They are the new TR8*2 lead screws Banggood.com just delivered. I will now have the ability to adjust layer heights in increments as small as 0.01 mm. It should be a big help when using variable layer heights in the Prusa version of Slic3r.

    Sent from my SAMSUNG-SM-N910A using Tapatalk
     
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  19. SPyKER

    SPyKER Active Member

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    And?
     
    #79 SPyKER, Mar 30, 2017
    Last edited: Mar 30, 2017
  20. WheresWaldo

    WheresWaldo Volunteer ( ͠° ͟ʖ ͡°)
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    @SPyKER

    Sorry, forgot to update, been busy trying to get U.B.L up and running on the R1. These worked perfectly, and at the same time I now have 0.01 mm per full stepper motor step. This should increase accuracy without the expense of going to 0.9° steppers. The biggest reason to do this is that Steppers like to and are designed to move in complete steps. The number of steps that the normally used steppers in 3D printing use are 200 and motors are designated to hold those positions solidly. The microsteps uses on all 3D printer boards are estimated and only held electrically based on those estimates. So even though the R1+Plus has the same 200 step steppers and the same 16 mircosteps the smallest complete step increment it can move is 0.02 mm on the Z axis.

    I am also experimenting with Prusa's version of Slic3r, where he has incorporated an easy method to have variable Z layer heights in zones on 3D prints. So now I know if my first layer of a curved section is 0.05 mm and the last one is 0.25 mm all the layers in the middle will fall on a full step boundary.
     
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