. .

Threaded View

Previous Post Previous Post   Next Post Next Post
  1. #11
    OK, looking at the gcode where I had the 2 crashes (when 'starting' after a 'feedhold') and I can see there are several straight line moves (must be geometry nodes all along in a straight line from when I was creating and changing the CAD), followed by a G2 radius arc in both cases.

    #1
    I've read about problems with feedhold in arcs so always feedhold on a straight edge. But I was definitely on the straight bit about half way along the top edge when I pressed feedhold. About line 930. It was some way off getting to the G2 ARC at the corner. When I hit start the machine went up in +Y and snapped the tool clean off.

    I've loaded the file onto my house PC (hence the DROs are all zero!) Here is the first one:
    Click image for larger version. 

Name:	crash1.jpg 
Views:	2938 
Size:	128.6 KB 
ID:	17956

    #2
    This time, on the same part, I was cutting along a straight edge at the bottom, -X direction, when I hit feedhold. It had just done line 1060. This time cycle start moved the machine in +Y. I hit e-stop straight away this time and recovered it. However, there was a gouge in the work piece (!). It's cosmetic but annoying none-the-less.

    Looking at the gcode shows another set of linear moves, followed by a G2 arc radius at the corner:
    Click image for larger version. 

Name:	crash2.jpg 
Views:	2883 
Size:	120.4 KB 
ID:	17957

    I'll go back to the CAD and see if there are repeat nodes in the geometry as a start, but I'm confused by this as I've used feedhold for years and not had this problem. Now twice on the same part!

    I went to Mach3 website in case there was a later version - but it's still R3.0.43.066 I which is what I am running now.


    EDIT:
    OK, the reason for the repeat straight moves is that there are tabs on those sides. Vectric obviously adds those moves in on every pass, but only adds the Z up and over move when the required depth is met. However, I was nowhere near the depth to create the tabs (they are only 2mm high) so that might be a coincidence. So, still confused about what is going on . . .
    Click image for larger version. 

Name:	CAM_cut2D.jpg 
Views:	2886 
Size:	46.7 KB 
ID:	17958


    EDIT2 / side note:
    I've had to do a few 'run from here' operations after hitting the e-stop recently. It is probably out of position as it could be mid-step so I've found you need to:
    1. Raise the tool right out of the workpiece
    2. Re-home the machine
    3. Press 'run from here' on the line you e-stopped on
    4. It will show you the required resume coordinates in a window. Before accepting these you should jog or MDI to the X and Y positions it shows. If you do not it will try to move straight to that location which could be through a clamp or the workpiece etc. if you are low. This has caught me out a couple of times!
    5. Press OK and it will rapid down in Z to the position it got to when the e-stop was pressed
    6. Start the spindle (or there is a check box if you use spindle control from Mach)
    7. Hit cycle start
    Last edited by routercnc; 16-03-2016 at 10:29 PM. Reason: more info
    Building a CNC machine to make a better one since 2010 . . .
    MK1 (1st photo), MK2, MK3, MK4

  2. The Following User Says Thank You to routercnc For This Useful Post:


Thread Information

Users Browsing this Thread

There are currently 18 users browsing this thread. (0 members and 18 guests)

Bookmarks

Posting Permissions

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