Upgrading Lead Screw?

This topic contains 8 replies, has 4 voices, and was last updated by Profile photo of edwardku edwardku 6 months, 2 weeks ago.

Viewing 9 posts - 1 through 9 (of 9 total)
  • Author
    Posts
  • #15969
    Profile photo of Benjamin Shaw
    Benjamin Shaw
    Participant

    Thinking about using a real lead screw. Wondering what a good equivalent would be that I could get for around $20?

    #15971
    Profile photo of Ryan
    Ryan
    Keymaster

    Nothing for under $20 is going to be an improvement.

    What is the goal of the “upgrade”, that will help in the selection? The right thing is a ball screw, but the prices reflect that.

    #15975
    Profile photo of Benjamin Shaw
    Benjamin Shaw
    Participant

    I saw this guy saying he made an upgrade to a lead screw. Would be willing to spend up to $40 if it’s worth it.

    #15976
    Profile photo of Ryan
    Ryan
    Keymaster

    What problem are you trying to solve? Why change?

    Backlash can be brutal on these things, it is different on a 3D printer where gravity is providing the anti backlash and the forces are only acting with gravity. On this CNC you are pushing down and your material is pushing back, making backlash a huge factor. Your cutting bit can actually vibrate up and down if you aren’t careful. If I though these where a good idea I would have used them. A ball screw has backlash compensation, a leadscrew needs added hardware for backlash compensation (we used to use a second nut and spring but too many people didn’t understand how to set it so I had to take it off).

    #15977
    Profile photo of Benjamin Shaw
    Benjamin Shaw
    Participant

    I don’t know enough about these things to even know what I’m trying to accomplish. Just saw it mentioned a few places, and thought that a real lead screw might be better somehow. Straighter? Smoother? Higher precision? I don’t know. Probably just go with the one in the kit for now.

    #17884
    Profile photo of Cesar
    Cesar
    Participant

    Hi vicious I had purchased this items at amazon
    https://www.amazon.com/gp/product/B017AR5QBS/ref=oh_aui_detailpage_o05_s00?ie=UTF8&psc=1
    described as follows 400mm Lead Screw 3D Printer Z Axis Lead Screw ACME Lead Screw 8mm Screw Pitch
    Specifications:
    Material: Stainless steel lead screw, copper nut
    Screw diameter: 8mm
    Length: 400mm
    Screw spacing: 2mm
    Lead of thread:8mm
    Range: Reprap makerbot 3d printer accessories
    3D engraving machine lead screw 400mm length with nut.
    Nut turn an around move 8mm
    Package include:
    1x 400mm lead screw
    1x Brass Nut

    The rod for my z axis I could I have used the prusa calculator to determine the correct micro step settings to replace the current settings on the marlin set up you have provided on the site I have not successfully determine the correct rotational amount with the information given on amazon thru trial and error I have approximated that 1600 as a better number than the 8mm 5120 the calculator provides could you illustrate the math followerd to calculthe steps for any given angular pitch

    #17885
    Profile photo of Ryan
    Ryan
    Keymaster

    It should be 800, once and a while 788.

    That leadscrew is not recommended for your z axis. Reasons are 2 posts up.

    #17899
    Profile photo of Cesar
    Cesar
    Participant

    Thank you I am certainly learning a lot I have taken the scenic route in getting my machine up and running I have fallen in just about every pot hole there could be in this road. But the adventure continues to be exiting?

    #24396
    Profile photo of edwardku
    edwardku
    Participant

    I understand the backslash problems(try to resolve it with antibackslash nut) but if I want to try lead screw which one will be better for MPCNC
    The one start two millimetres lead per turn or four start eighth millimetres lead per turn.

Viewing 9 posts - 1 through 9 (of 9 total)

You must be logged in to reply to this topic.