Solved TM3 Issue transitioning from lines to arcs and arcs to lines: stuttering/jumping


Results 1 to 6 of 6

Thread: TM3 Issue transitioning from lines to arcs and arcs to lines: stuttering/jumping

  1. #1
    Registered
    Join Date
    Dec 2013
    Posts
    13
    Downloads
    0
    Uploads
    0

    Default TM3 Issue transitioning from lines to arcs and arcs to lines: stuttering/jumping

    Machine:
    Torchmate Small Shop Machine, 4x4, ~2007 original purchase
    501A(?) USB Signal Generator
    3A stepper motors (didn't think to write down the PNs)
    2.25hp DeWalt Router
    1/4in solid carbide router bit
    Torchmate 3 Driver Software (Torchmate's website is down, and I'm at work, so I can't double-check this!)
    BobCAD/CAM V21 gCode generation, Torchmate w/ FlashCut Post-Processor
    Computer: Windows 7 64bit (w/ 64bit 501A driver)


    I have a Torchmate Small Shop machine 4x4 table I just setup and am using as a CNC router. As of now I have successfully cut circles with good interpolation (i.e. they turned out consistently round and of the proper dimensions) and a few polygon profiles, both with no issues.

    My problem is that when I program the machine to cut a rectangle with fillets on the corners the drive 'jumps' or 'stutters' or 'jerks' right at the transition from cutting a straight line to an arc.

    I tried reducing feed rates down to 10ipm, reducing drive accelerations down to 2ips^2, turned the feedrate up to 12ipm (above the starting feedrate of 11.75ipm), I checked the X, Y, and Z drives for any loose drive components (belts, gears, etc) or backlash and fixed a few things, but they didn't solve my problem. The only adjustment that sort-of masked the problem was changing the maximum arc feedrate down to 1ipm, I experimented with it set to 10ipm and 70ipm (default).

    The problem was reproducible with no cutting forces on the router, I ran it 'in air' and still saw the stutter/jump/jerk.

    Any thoughts on what to try next? Any help would be greatly appreciated.

    Edit: I think I should add that the cuts are still turning out very repeatably. Its not missing any steps that I can detect after multiple passes on the same profile, even under cutting loads.

    Similar Threads:
    Last edited by jch13; 12-09-2013 at 07:48 PM.


  2. #2
    Member
    Join Date
    Mar 2004
    Location
    Wisconsin
    Posts
    413
    Downloads
    31
    Uploads
    1

    Default

    Flashcut can negotiate thru all sorts of mixed geometry be it short lines or short lines mixed with arcs without breaking a sweat when things are set correctly, so its not the control in itself....

    Are you using, or have you done a "save as" for a new setup from your plasma setup file ? If so, you would need to scour thru it to make sure things set for productive plasma operation do not inhibit router operations

    In your configuration/ feedrate/ramping section, is your Continuous Contouring Feedrate Tol. set higher than your start stop feedrate and ramping rate ? CCFT usually needs to be set higher or you can get momentary pauses at the end of geometry.

    In the same place, did the plasma system have the Max arc feedrate (under General) set to a lower rate than your trying to achieve ?

    In your configuration/ Motion Delays, has there been a change by chance to the "Direction Change Delays" or "Corner Delays" ? ?

    Flashcut does not have a specific setting for anything like "exact Stop" others are familiar with.... so it can't be that.

    I'll give this some more thought as to what you might be seeing there.......

    Chris L


  3. #3
    Registered
    Join Date
    Dec 2013
    Posts
    13
    Downloads
    0
    Uploads
    0

    Default

    Quote Originally Posted by datac View Post
    Flashcut can negotiate thru all sorts of mixed geometry be it short lines or short lines mixed with arcs without breaking a sweat when things are set correctly, so its not the control in itself....

    Are you using, or have you done a "save as" for a new setup from your plasma setup file ? If so, you would need to scour thru it to make sure things set for productive plasma operation do not inhibit router operations
    It was a fresh install from scratch, so I've only adjusted from default values on everything, though I will take yet another look through.

    Quote Originally Posted by datac View Post
    In your configuration/ feedrate/ramping section, is your Continuous Contouring Feedrate Tol. set higher than your start stop feedrate and ramping rate ? CCFT usually needs to be set higher or you can get momentary pauses at the end of geometry.
    I don't think I have set a value named anything like that. I will definitely look into this.

    Quote Originally Posted by datac View Post
    In the same place, did the plasma system have the Max arc feedrate (under General) set to a lower rate than your trying to achieve ?
    Not sure, though when I have tried to make poor settings changes the software has caught it. I will double-check.

    Quote Originally Posted by datac View Post
    In your configuration/ Motion Delays, has there been a change by chance to the "Direction Change Delays" or "Corner Delays" ? ?
    No. I tried adding a 0.1s direction change delay, but it didn't affect transitioning from line to arc. That has been removed now though.

    Quote Originally Posted by datac View Post
    Flashcut does not have a specific setting for anything like "exact Stop" others are familiar with.... so it can't be that.

    I'll give this some more thought as to what you might be seeing there.......
    I appreciate it, thanks!



  4. #4
    Registered
    Join Date
    Dec 2013
    Posts
    13
    Downloads
    0
    Uploads
    0

    Default

    Fixed!

    Feedrates were lower than the 'start movement' feedrates, and the CCFT rates were never initialized it seemed. All is well now.

    Thanks datac!



  5. #5
    Member
    Join Date
    Mar 2004
    Location
    Wisconsin
    Posts
    413
    Downloads
    31
    Uploads
    1

    Default

    Well, its rather easy when you have a great control to work with !

    By the way, all those settings can be a real challenge to get the most of of your machine..... If you go to Flashcut's site and download the user manual, they do have a really good section on what those settings all accomplish as well as a routine/step by step method a person can use to dial it in.

    Glad I could help.

    Chris L


  6. #6
    Registered
    Join Date
    Dec 2013
    Posts
    13
    Downloads
    0
    Uploads
    0

    Default

    Quote Originally Posted by datac View Post
    Well, its rather easy when you have a great control to work with !

    By the way, all those settings can be a real challenge to get the most of of your machine..... If you go to Flashcut's site and download the user manual, they do have a really good section on what those settings all accomplish as well as a routine/step by step method a person can use to dial it in.

    Glad I could help.
    Indeed!

    I found some tuning routines in Torchmate's documentation, and the FlashCut manual you mentioned, and I have a dial indicator to measure for missed steps, so that will be my next activity.

    Edit: looks like Torchmate copied and pasted the flashcut procedure into their manual!

    Again, I appreciate it!



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

TM3 Issue transitioning from lines to arcs and arcs to lines: stuttering/jumping

TM3 Issue transitioning from lines to arcs and arcs to lines: stuttering/jumping