Need Help! OX CNC not cutting correctly


Results 1 to 12 of 12

Thread: OX CNC not cutting correctly

  1. #1
    Registered
    Join Date
    Jun 2013
    Location
    New Zealand
    Posts
    11
    Downloads
    0
    Uploads
    0

    Default OX CNC not cutting correctly

    Hi,

    I have build an OX CNC and I cant get it to cut the model correctly.

    An example of something I have tried to cut is attached along with the GCODE file.

    The letters were created in Illustrator and imported into Fusion 360 to extrude and create the toolpath. I have saved it as generic grbl.

    The simulation is fine and when I open in in bCNC it also looks fine. While machining bCNC preview window shows it machining correctly but its not. It pauses and starts to run lines through my model.

    I am using Audrino Uno with CNC Sheild, running GRBL.

    This is getting really frustraiting and any help would be appreciated.

    Thank you

    Michael

    Similar Threads:
    Attached Thumbnails Attached Thumbnails OX CNC not cutting correctly-20170724_121347-jpg  


  2. #2
    Registered
    Join Date
    Jun 2017
    Location
    Australia
    Posts
    15
    Downloads
    0
    Uploads
    0

    Default Re: OX CNC not cutting correctly

    Autodesk also do "Artcam", its a bit simpler to use. Maybe give that a try for your first try cutting
    ..

    Sent from my LG-H870DS using Tapatalk



  3. #3
    Registered
    Join Date
    Jun 2013
    Location
    New Zealand
    Posts
    11
    Downloads
    0
    Uploads
    0

    Default Re: OX CNC not cutting correctly

    I just tried Artcam 2018 half an hour ago and I have a simular issue, also the Z Axis cuts right down into the stock material so deep the axis can move.

    Attached Thumbnails Attached Thumbnails OX CNC not cutting correctly-20170724_132612-jpg  


  4. #4
    Member KH0UJ's Avatar
    Join Date
    Jul 2016
    Location
    Philippines
    Posts
    660
    Downloads
    0
    Uploads
    0

    Default Re: OX CNC not cutting correctly

    Can you post your sample G-code here?



  5. #5
    Member Biggs427's Avatar
    Join Date
    Feb 2016
    Location
    Canada
    Posts
    285
    Downloads
    0
    Uploads
    0

    Default Re: OX CNC not cutting correctly

    Missed step? If you do a dry run without actually cutting, does it follow the right tool path?

    It could also be a lead-in/out problem. Which toolpath are you using in F360? Pocket, contour, engrave?



  6. #6
    Member
    Join Date
    May 2005
    Location
    USA
    Posts
    3920
    Downloads
    0
    Uploads
    0

    Default Re: OX CNC not cutting correctly

    Kinda looks like a lose of Z position. I'd try adjusting your acceleration and max velocity for Z to see what happens. This could also be a mechanical issue.

    As someone mentioned above try cutting air and see if your axises all return to the same position at the end of the run.



  7. #7
    Member Biggs427's Avatar
    Join Date
    Feb 2016
    Location
    Canada
    Posts
    285
    Downloads
    0
    Uploads
    0

    Default Re: OX CNC not cutting correctly

    Might look stupid, but are you certain the collet holds the cutter correctly? It happened to me when collet wasn't tight enough. Holding wasn't good enough and since the cutter was an upcut one, it was pulled out of the collet.

    At the end of the job, re-home your machine and then measure the tool lenght offset. If it's not the same, recheck your collet.



  8. #8
    Registered
    Join Date
    Jun 2013
    Location
    New Zealand
    Posts
    11
    Downloads
    0
    Uploads
    0

    Default Re: OX CNC not cutting correctly

    Quote Originally Posted by Biggs427 View Post
    Missed step? If you do a dry run without actually cutting, does it follow the right tool path?

    It could also be a lead-in/out problem. Which toolpath are you using in F360? Pocket, contour, engrave?

    Hi,

    I think it is missed step. I have figured out that the z axis is ok. Its because it steps down another 2mm for second pass but isn't following the correct toolpath and therefore cutting at 4mm.

    The X axis seems fine but the Y is loosing it's position.



  9. #9
    Registered
    Join Date
    Jun 2013
    Location
    New Zealand
    Posts
    11
    Downloads
    0
    Uploads
    0

    Default Re: OX CNC not cutting correctly

    I there a way of attaching the file, there are a lot of lines.OX CNC not cutting correctly-gcode-jpg



  10. #10
    Registered
    Join Date
    Jun 2013
    Location
    New Zealand
    Posts
    11
    Downloads
    0
    Uploads
    0

    Default Re: OX CNC not cutting correctly

    I have created an E to machine in Artcam 2018, attached is the screen shot of what it should look like. In fusion 360 I was using contour. I don't think that the G-Code is the problem.

    As you can see from the video it seems to pause but the toolpath preview in bCNC carries on. The line it cuts through the middle should be back at the top 2mm deeper.

    Could it be the drivers shutting down, pots need turning up/down etc? I have read some stuff about this.

    Also there is a link to a video of it machining, so that you can see what it is doing.

    OX CNC not cutting correctly-e-jpg

    OX CNC not cutting correctly-20170726_140633-jpg

    Last edited by mreitt; 07-26-2017 at 01:06 PM.


  11. #11
    Registered
    Join Date
    Jun 2017
    Location
    Australia
    Posts
    15
    Downloads
    0
    Uploads
    0

    Default Re: OX CNC not cutting correctly

    Quote Originally Posted by mreitt View Post
    I have created an E to machine in Artcam 2018, attached is the screen shot of what it should look like. In fusion 360 I was using contour. I don't think that the G-Code is the problem.

    As you can see from the video it seems to pause but the toolpath preview in bCNC carries on. The line it cuts through the middle should be back at the top 2mm deeper.

    Could it be the drivers shutting down, pots need turning up/down etc? I have read some stuff about this.

    Also there is a link to a video of it machining, so that you can see what it is doing.

    OX CNC not cutting correctly-e-jpg

    OX CNC not cutting correctly-20170726_140633-jpg
    Did you sort this out? Did you try cutting a similar shape and see if same movements go wrong?

    Sent from my LG-H870DS using Tapatalk



  12. #12
    Member KH0UJ's Avatar
    Join Date
    Jul 2016
    Location
    Philippines
    Posts
    660
    Downloads
    0
    Uploads
    0

    Default Re: OX CNC not cutting correctly

    By just watching on your video clearly your problem is not in the software, it`s in your hardware, your Y axis ball screw getting stuck that`s why it` s missing the route path, sometimes it could be just miss aligned ball screw mechanism (Not Smooth), ball screw got bent during shipping, all the way down to a just a simple dust accumulation on the ball screw itself, try to open your ball screws, clean it if it`s dirty, lubricate it with baby oil or cooking oil, not the thicker oil (learned my mistakes) lubricating it with gear oil tends to attract more dust particles to stick to the ball screw then stuck again in a short period of time.

    Edit: sometimes it could be your machine calibration, (steps/min on XYZ) wrong setting on these could result to a low torque stepper motors, the moment it encounters harder curve or harder material on the route path it tends to miss it resulting to shortcut routing due to it`s less torque.



Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  


About CNCzone.com

    We are the largest and most active discussion forum for manufacturing industry. The site is 100% free to join and use, so join today!

Follow us on


Our Brands

OX CNC not cutting correctly

OX CNC not cutting correctly