Welcome to Our Community

Some features disabled for guests. Register Today.

4040 CNC unable to set z probe it seems

Discussion in 'CNC Mills/Routers' started by John Ger, Jun 15, 2024.

  1. John Ger

    John Ger New
    Builder

    Joined:
    Jun 14, 2024
    Messages:
    31
    Likes Received:
    6
    I have a vevor cnc 4040 unit and can manually set the zprobe with a piece of paper but I want to try to use the generic round 20mm thick z probe. I have installed it and let it do its thing. I wnet in and in the custom probe set it at the z for 20mm as that is the thickness of it but. it seems to accept everything but then moves about 20 mm above the work surface after that. I have tried it on the work surface and the bare deck with the same result.

    I have read the documentation multiple times and all the post I can find. I can't seem to to solve my problem... I also have a brain issue that sometimes makes it difficult ro process info so not sure if that comes into effect.

    I love openbuilds so much that i think I'll move my 20 watt laser over to this machine and make it dual purpose.
    I do need to do a control to turn on my vacuum or air system depending if I am running my laser or my router head
     
  2. Peter Van Der Walt

    Peter Van Der Walt OpenBuilds Team
    Staff Member Moderator Builder Resident Builder

    Joined:
    Mar 1, 2017
    Messages:
    15,139
    Likes Received:
    4,337
    After Probing, do a GOTOZERO to see if its set correctly?
     
  3. John Ger

    John Ger New
    Builder

    Joined:
    Jun 14, 2024
    Messages:
    31
    Likes Received:
    6
    when it zeros (after doing the z-probe and setting the z-offset to 25mm) it set the zero at about 10mm above the material (I am doing the z-probe on the workpiece) when it is working and trying to work about 5mm above the work surface. when it zereos it is about 5mm above the worksurface

    Is the correct action to "correct the z offset an additional amount" to make up for this difference?
     
    #3 John Ger, Jun 16, 2024
    Last edited: Jun 16, 2024
  4. Giarc

    Giarc OpenBuilds Team
    Staff Member Moderator Builder Resident Builder

    Joined:
    Jan 24, 2015
    Messages:
    3,022
    Likes Received:
    1,690
    Earlier, I read your post that you deleted. Just getting around now to trying to help.

    1) Have you homed the machine before doing anything job related?

    2) Are your limit switches set up in the industry standard way (Z is up, X is right Y is back)? You mentioned a error 9 and hard limit strikes in the deleted post.

    3) If using Openbuilds Control, in the trouble shooting tab, does the appropriate limit switch show it is activated when you manually trigger it? Has the machine been calibrated?

    4) Has the machine been calibrated?

    5) What CAM software are you using? What is your safe Z height in that software?
     
  5. John Ger

    John Ger New
    Builder

    Joined:
    Jun 14, 2024
    Messages:
    31
    Likes Received:
    6
    Answers
    1.) yes it is homed before a project starts
    2.) yes
    3.) yes on the limit switches
    4.) funny that you mention that. I thought about it and tried the calibrate of xyz and wow I am big dumb dumb head. I have a 400mm Bed X 400mm bed and lo and behold it was only reading about 125mm yet traveling full lengths. So i did the 100mm movement test and ended up in the 300 mm of travel. so I reset it through that, not sure if that is right, I don't think it is but it is now reading correctly.

    Then I used the cnc hello world and set it at 5mm safe travel 8mm first depth of cut and 10mm finish. I manually did the paper test and it zeroed good and cuts well with a 3mm bit. I recompiled using openbuilds cam software. but i Have to manually turn on my router so I know i need to figure that out too.

    It is much slower in jog even when i went in set the speeds higher in GRBL so I know am missing something on that.
    I did the hello world and it took 18 minutes.

    I used to be a millwright by trade so am used to doing things like this but have a tumor and early stage MS and sometimes my brain gets foggy that's why my emails were doing what they were doing as sometimes the fog lifts and i can process info better
     
  6. Giarc

    Giarc OpenBuilds Team
    Staff Member Moderator Builder Resident Builder

    Joined:
    Jan 24, 2015
    Messages:
    3,022
    Likes Received:
    1,690
    To get a good accurate calibration, put a pointy endmill like a V bit in and jog it at the longest distance you can next to a measuring tool. The longer your test the more accurate it will be. OpenBuilds Control has a Calibration Wizard that will walk you through it.

    When you changed the grbl settings did you remember to save the changes? I have for got to do that myself in the past.
     
  7. John Ger

    John Ger New
    Builder

    Joined:
    Jun 14, 2024
    Messages:
    31
    Likes Received:
    6
    What about the speed issue I am seeing in jogging it, I just doubled the settings from 500 to 1000 and 1000 to 200 on them? Why is the router head not starting after I have compiled the code in the open builds cad, do I need to add a geode in the compiling, I assumed it added it?

    thanks for the help I appreciate it
     
  8. Peter Van Der Walt

    Peter Van Der Walt OpenBuilds Team
    Staff Member Moderator Builder Resident Builder

    Joined:
    Mar 1, 2017
    Messages:
    15,139
    Likes Received:
    4,337
    CAM > Settings tab > Settings button > Tell it you have a Router

    upload_2024-6-17_15-12-41.png
    If your steps per mm was off, it will feel different in speed, because before the speeds were wrong by the same factor your moving distance was wrong (it thinks its moving 125mm/min, but its covering 400mm of actual move, yeah, will feel 3x slower now that its fixed)
    Correct Max Rate and Acceleration by the same margin


    More likely then either Z isn't Calibrated, or you are slipping and losing mechanical position.
     
  9. John Ger

    John Ger New
    Builder

    Joined:
    Jun 14, 2024
    Messages:
    31
    Likes Received:
    6


    Where do I find the z calibration is it in the grbl side or can it be done in the software side. There is no slipping. So definitely z calibration.

    so use the iot router spec instead the variable? Supprised there isn’t a choice for a fixed speed router. When I set up on that screen is it better to use the true movements I’ve of the bed or use the indicated size of 400mmX400mm?
     
  10. John Ger

    John Ger New
    Builder

    Joined:
    Jun 14, 2024
    Messages:
    31
    Likes Received:
    6
    OK i am a big fat fibber. I didn't notice that somehow openbuilds/GRBL changed my steps per mm to that of a screw instead of belt. So, I Went through and reset that (super hard for my brain now LOL) ended up being on the dot at 80 steps per mm.so now i have that resolved. I did verify with the wizard so that was nice. I am using openbuild cam to do my g-code conversion now and am playing with the settings i want. Tomorrow I will try the zprobe again. so most likely self-induced confidence LOL.

    Now the questions I have set maximum travel in maximum movement at the travel of the unit at 400X400X90 as that is the maximum travel to the end of the limit switches and i have set home at just off the switches, is that correct or should home be at the switches all being engaged?
    I have set the homing pull off at 5mm, is that to much?
    Travel speed for the nema 24's I set at 2500mm/min and acceleration at 200mm/sec, i think that is about right?

    I want to turn on the water cooling to use to turn on an appropriate relay to operate my vacuum when the router is actually being used to engrave not just when the router is turned on (so it isn't running when i am setting the machine) what is the best way to do that?

    Again thanks for the help sorry about my silly assumptions.
     
  11. David the swarfer

    David the swarfer OpenBuilds Team
    Staff Member Moderator Builder Resident Builder

    Joined:
    Aug 6, 2013
    Messages:
    3,481
    Likes Received:
    1,923
    use the coolant output
    docs:blackbox-x32:connect-coolant [OpenBuilds Documentation]
     
  12. John Ger

    John Ger New
    Builder

    Joined:
    Jun 14, 2024
    Messages:
    31
    Likes Received:
    6
  13. David the swarfer

    David the swarfer OpenBuilds Team
    Staff Member Moderator Builder Resident Builder

    Joined:
    Aug 6, 2013
    Messages:
    3,481
    Likes Received:
    1,923
    you don't, you let the CAM do it for you by selecting 'coolant on' for the tool.
    Then the CAM will insert the codes for coolant on and coolant off at the points where the router turns on and off.
     
  14. John Ger

    John Ger New
    Builder

    Joined:
    Jun 14, 2024
    Messages:
    31
    Likes Received:
    6
    ok I wasn't sure that it would do that and I found that it did which makes it great
     
  15. John Ger

    John Ger New
    Builder

    Joined:
    Jun 14, 2024
    Messages:
    31
    Likes Received:
    6
    I am a bufoon forgot the z axis was lead screw so steps were way offf........corrected and working fine
     

Share This Page

  1. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
    By continuing to use this site, you are consenting to our use of cookies.
    Dismiss Notice