Guest
Show Posts
1
General Mach Discussion / Resolved: Ugly Circles pt 2: Troubleshooting for a beginner
« on: February 21, 2007, 12:46:02 PM »
Good morning all. Your posts have been so helpful to me in getting me to the point where I can at least cut some semblance of a part. But now I'm stuck.
problem: circles and arcs not 'smooth'
symptoms: motor/motion appears to 'chatter' and the cut edge appears 'rough' and 'wavy'. It also appears as if a step is maybe being 'lost?' in that the geometry is off. When the cut is finished, the end of the path is not exactly where it should be.
cutting: just cutting .125" HIPS, using a good carbon O-flute bit with neutral spiral, using Mach 3
Here's what I know and have done so far:
-Cuts straight and clean along x and y axis. Only seams to be a problem on arcs or when x and y are working in rapid succession (generally).
-I did several diagonal cuts about 10 inches long and didn't noticeably see the problem.
-Then I cut a few squares rotated 45 degrees and did see the problem.
-The problems don't seam to manifest themselves in the same parts of the toolpath each time.
-The problem appears to 'muted' when I switch to Exact Stop, but is still clearly visible.
-I have tuned motors by increasing and decreasing acceleration with no noticeable results.
-I have adjusted feed rates on the cut. A faster rate appears to improve it slightly, but it's clearly still a problem.
-I've moved the cuts around the table to make sure it's not isolated to a particular section.
-Changing direction of the toolpath has no impact.
-I have checked backlash...though I don't know if what I did was right. I took a depth mic and set it up and sent the machine back and forth on the x and y and made sure it came back to the same place. I appear to be very lucky in that backlash does not appear to be a problem.
I have learned quite a bit from these forums, and have learned a fair amount about this problem through thread searches, but I'm still stuck. And then there's the element of the standoff between the mechanical, electrical, controller, and software elements. That makes it hard to sort out where to start troubleshooting.
First off...if anybody has any ideas or Mach3 settings to fiddle with...I'd be more than grateful.
But, equally important, if anyone can point me in a troubleshooting direction that could help me eliminate culprits, I'd be more than grateful as well.
problem: circles and arcs not 'smooth'
symptoms: motor/motion appears to 'chatter' and the cut edge appears 'rough' and 'wavy'. It also appears as if a step is maybe being 'lost?' in that the geometry is off. When the cut is finished, the end of the path is not exactly where it should be.
cutting: just cutting .125" HIPS, using a good carbon O-flute bit with neutral spiral, using Mach 3
Here's what I know and have done so far:
-Cuts straight and clean along x and y axis. Only seams to be a problem on arcs or when x and y are working in rapid succession (generally).
-I did several diagonal cuts about 10 inches long and didn't noticeably see the problem.
-Then I cut a few squares rotated 45 degrees and did see the problem.
-The problems don't seam to manifest themselves in the same parts of the toolpath each time.
-The problem appears to 'muted' when I switch to Exact Stop, but is still clearly visible.
-I have tuned motors by increasing and decreasing acceleration with no noticeable results.
-I have adjusted feed rates on the cut. A faster rate appears to improve it slightly, but it's clearly still a problem.
-I've moved the cuts around the table to make sure it's not isolated to a particular section.
-Changing direction of the toolpath has no impact.
-I have checked backlash...though I don't know if what I did was right. I took a depth mic and set it up and sent the machine back and forth on the x and y and made sure it came back to the same place. I appear to be very lucky in that backlash does not appear to be a problem.
I have learned quite a bit from these forums, and have learned a fair amount about this problem through thread searches, but I'm still stuck. And then there's the element of the standoff between the mechanical, electrical, controller, and software elements. That makes it hard to sort out where to start troubleshooting.
First off...if anybody has any ideas or Mach3 settings to fiddle with...I'd be more than grateful.
But, equally important, if anyone can point me in a troubleshooting direction that could help me eliminate culprits, I'd be more than grateful as well.