587,547 active members*
3,359 visitors online*
Register for free
Login
Results 1 to 6 of 6
  1. #1
    Join Date
    Apr 2013
    Posts
    34

    Arc radius too small

    Hi,

    KmotionCNC sometimes tells "arc radius too small" on my programs, although in Mach3 all is good. At this moment I solved this by increasing radius by few microns manually. It there a way to adjust arc endpoint tolerances in KmotionCNC?

    Thank You.

  2. #2
    Join Date
    May 2006
    Posts
    4049

    Re: Arc radius too small

    Hi mk00,

    The code only allows the radius to be short of the required distance by a fixed limit of 1e-12. Do you have an example GCode Fragment? Defining a near semi circle using Radius mode may cause large path errors as the slightest change in the specified values can shift the circle center by a significant amount. Does your CAD have another option? Or can it specify more digits of precision?

    Regards
    TK
    http://dynomotion.com

  3. #3
    Join Date
    Apr 2013
    Posts
    34

    Re: Arc radius too small

    Hi, Tom

    Here is example program. May be it is possible to modify postprocessor, but i dont know how. I`we read that LinuxCNC have option for adjusting arc endpoint tolerance.

  4. #4
    Join Date
    Aug 2015
    Posts
    52

    Re: Arc radius too small

    may be you use inch, please check ,some control system can not us inch ,so the system will show the "arc radius too small".
    To be first brand CNC Router Manufacturer & Wholesaler Platform

  5. #5
    Join Date
    Apr 2013
    Posts
    34

    Re: Arc radius too small

    Quote Originally Posted by cncjack01 View Post
    may be you use inch, please check ,some control system can not us inch ,so the system will show the "arc radius too small".
    No, both CAM and KmotionCNC in millimeters. If I will increase radius manually by 0.001 all will work

  6. #6
    Join Date
    May 2006
    Posts
    4049

    Re: Arc radius too small

    Hi mk00,

    We will add an option to change the Tolerance.

    Using R mode is a poor way to specify a semi-circle. I did the math for a 100mm Radius. Changing R by only 1um shifts the arc center by 0.477mm. So most CAM systems avoid this.

    =SQRT(100^2 - (100 - 0.001)^2) = 0.477

    Regards
    TK
    http://dynomotion.com

Similar Threads

  1. Arc Radius Too Small!
    By Stevos758 in forum Tormach PathPilot™
    Replies: 12
    Last Post: 05-05-2015, 01:25 PM
  2. Small g01 moves on big radius?
    By tkgb in forum SprutCAM
    Replies: 18
    Last Post: 01-22-2014, 03:06 AM
  3. Small radius good Large radius bad
    By K2Developmentab in forum Fadal
    Replies: 2
    Last Post: 09-26-2013, 07:26 PM
  4. Replies: 1
    Last Post: 05-15-2013, 08:52 AM
  5. helical radius too small l
    By bala955 in forum Surfcam
    Replies: 2
    Last Post: 06-30-2009, 03:28 PM

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
  •