1. Dismiss Notice
  2. Hey guyz. Welcome to the All New Phlatforum!



    Sign Up and take a look around. There are so many awesome new features.

    The Phlatforum is a place we can all hang out and

    have fun sharing our RC adventures!

  3. Dismiss Notice
  4. Hey guyz. Welcome to the All New Phlatforum!



    Sign Up and take a look around. There are so many awesome new features.

    The Phlatforum is a place we can all hang out and

    have fun sharing our RC adventures!

GREAT NEWS! Backlash working on USB board...

Discussion in 'Troubleshooting and Build Support' started by Flashsolutions, Jan 26, 2011.

  1. Flashsolutions

    Flashsolutions Active Member

    Offline
    Messages:
    1,123
    Trophy Points:
    38
    Location:
    Leesburg, Florida
    Yes, this is the video that I ultimately watched which got me on the backlash track. The shuttle acceleration in Mach3 must be set to .005 in the general config tab. I should have mentioned that in my video as well.

    In his video, he uses .001 inch increments to bump the axis. I preferred to use a bigger granularity. I used .1" as my reference increment and it accomplished the same goals. I don't recall if if was mentioned in the Hoss video about zeroing the axis before you move it. You must do that in order to get accurate readings.

    I recommend everyone who is going to setup backlash watch this video in its entirity. He is cutting aluminum which makes it easier to measure the out of roundness or egg shape that occurs when backlash is present, but the pictures should be familiar to those having backlash issues.




     
  2. dugd1013

    dugd1013 Member

    Offline
    Messages:
    135
    Trophy Points:
    16
    Location:
    Air Capital of Kansas
    Kind of a dumb question but, I want to be sure I understand what files you are running in the "beta" software to fix the backlash problem. I checked the Planet-CNC website and saw the latest beta version is 2.10.1101.3001, am I correct in assuming that this version contains the backlash fix since it is numerically advanced from the referenced 2.10.1101.2601? Then, if that assumption is correct, are you replacing just the single download file in the CNC program folder or are you building a second program folder? As I was messing with the download file last night it kept requiring firmware updates each time I closed out and looked at the previous version. Since I know just enough to be dangerous, I thought I might ask what the proper way to work through this issue is without jacking up my files. :twitch:
     
  3. Flashsolutions

    Flashsolutions Active Member

    Offline
    Messages:
    1,123
    Trophy Points:
    38
    Location:
    Leesburg, Florida
    2601 or later should have the backlash correction enabled. It is a single file replacement of the controller software.

    If you have two directories and switch between them when they have different versions, the controller will request an update so that the firmware matches the software in use.


     
  4. ToxicToast

    ToxicToast Down in the weeds. Staff Member

    Offline
    Messages:
    483
    Trophy Points:
    18
    Location:
    Roseville, CA
    Thanks for a fantastic video explanation, Larry. I appreciate you taking the time to share these things with us. I hadn't thought of the use of the end-caliper-slide as a way of measuring the X overshoot. I also had my acceleration curves set wrong in USBCNC, and I think the smooth starts are helping the router negotiate the material better.

    I am still having small, but noticeable discrepancies in my cuts. Really only notice them on the micro stuff I am doing, and I am sure it would be much more dramatic when I get back to cutting balsa and ply. Hopefully, the new rollers will go a long way at making my cuts truer and get my home returns more precise.

    Do you calibrate your Y axis for backlash, or is this a non issue? If so, what method would you suggest to calculate? I find it difficult to get in there and get an accurate measurement.

    Thanks again for your awesome videos, warts and all as they say. I am now looking into what it would take to achieve a tool change capability in USBCNC but that is a horse of another...
     
  5. dugd1013

    dugd1013 Member

    Offline
    Messages:
    135
    Trophy Points:
    16
    Location:
    Air Capital of Kansas
    I did my Y axis with a magnet stand seated on top of the pressure rollers using a dial indicator depth gauge and 90 degree arm off of the stand. I ended up with .014 backlash in the Y axis. Since my X axis came in at .015 and my Z axis was .000, I'm convinced the backlash error is in the belt and pulley combo. Something to consider in the future as a wear indicator.

    Just my :02cents:

    Doug
     
  6. Flashsolutions

    Flashsolutions Active Member

    Offline
    Messages:
    1,123
    Trophy Points:
    38
    Location:
    Leesburg, Florida
    I have not setup the backlash on my Y axis as it seems to okay, but I should at least check it.

    The dial calipers can be used here as well. In one of my other videos in which I showed how to calibrate the axis with a dial caliper, the same method could be used. Basically you are just resting the caliper head against the side of the machine and using the slider to rest against the gantry.

    Then move the Y axis as you did for the X and measure the backlash when you reverse direction.

    As dugd1013 noted, .014 backlash seems to be about the same value as I was measuring on my X axis earlier. If you are still not getting round circles, then I would definitely check the Y axis as well.

    I just saw the pictures of the new rollers Mark is working on. They look awesome! Those should definitely make your home returns (tracking) more precise, but I have a feeling as dugd1013 mentioned, that the pulley drives will always need some amount of backlash correction. Mark may have more information on this since he has been testing the new rollers.



     

Share This Page