Hello Guest it is December 15, 2019, 02:10:15 PM

Author Topic: CNC Router not cutting all square outside corners  (Read 1193 times)

0 Members and 1 Guest are viewing this topic.

CNC Router not cutting all square outside corners
« on: August 29, 2017, 04:19:51 PM »
I just finished setting up a Chinese Router and was doing my first test cut.  It was a simple Rectangle with square outside corners.  I sue V carve pro and the G code seems to be fine but 3 of the 4 corners were rounded.  Anyone have any ideas?

Thanks
Rickh

Offline ger21

*
  • *
  •  6,291 6,291
    • View Profile
    • The CNC Woodworker
Re: CNC Router not cutting all square outside corners
« Reply #1 on: August 29, 2017, 05:25:28 PM »
You are running in CV mode, and Mach3 is rounding the corners in order to try and maintain constant velocity. The slower your acceleration, the more rounding you'll see. One thing you can do is go to General Config, and set Stop CV on Angles to 89, and enable it.
Gerry

2010 Screenset
http://www.thecncwoodworker.com/2010.html

JointCAM Dovetail and Box Joint software
http://www.g-forcecnc.com/jointcam.html
Re: CNC Router not cutting all square outside corners
« Reply #2 on: August 29, 2017, 06:12:08 PM »
That worked.  I am new to Mach 3 - my previous CNC had proprietary control software and not so many variables to deal with.  Would it also be a good idea to increase the acceleration?

Thanks for the quick response!

Offline ger21

*
  • *
  •  6,291 6,291
    • View Profile
    • The CNC Woodworker
Re: CNC Router not cutting all square outside corners
« Reply #3 on: August 29, 2017, 08:58:57 PM »
If your machine can handle it, higher acceleration is usually desirable.
Gerry

2010 Screenset
http://www.thecncwoodworker.com/2010.html

JointCAM Dovetail and Box Joint software
http://www.g-forcecnc.com/jointcam.html
Re: CNC Router not cutting all square outside corners
« Reply #4 on: August 30, 2017, 07:53:30 PM »
Unfortunately, one more issue if you don't mind.  The x and y axis do not seem to hold their calibration settings.  I thought they were calibrated perfectly, then I cut a simple square and one side is almost .125 larger than the other.  Re-calibrated and once again one side is slightly larger than the other.  I first used a standard tape measure to calibrate at several different distances and then after that was dialed in I used a dial indicator for fine tuning. 

Thanks in advance!