Page 3 of 6 FirstFirst 12345 ... LastLast
Results 21 to 30 of 53

Thread: Drifting Skipping Axis?

  1. #21
    Join Date
    Feb 2016
    Posts
    44

    Default

    Lastly, here is me moving the gantry pushing on the left side (side with the worst bearing imo):

    Towards the end of the video you can hear it bind several times as it runs along.
    Sadly, I've also pushed the gantry around without that bad bearing attached and I still get these binding issues. However, perhaps that could be a symptom of simply not having equal load support without that 4th bearing attached? Who knows...
    Chris

  2. #22
    Join Date
    Apr 2013
    Location
    Kennebunkport, Maine
    Posts
    3,983

    Default

    I wouldn't push the gantry around like that. Motor plus electricity= movement...motor plus movement= electricity.....you can fry components on your board unless motor wires have been disconnected
    Scott Plaisted
    2013 Desktop/spindle/VCP 9
    Maine

  3. #23
    Join Date
    Feb 2016
    Posts
    44

    Default

    That's what I would have figured too... I never had until the Shopbot folks told me to...
    Chris

  4. #24
    Join Date
    Dec 2007
    Posts
    2,270

    Default

    Be very careful doing that with your steppers plugged in

  5. #25
    Join Date
    Feb 2016
    Posts
    44

    Default

    I had that discussion with them and the rates at which I'm doing these tests damage is not likely.
    That said: hopefully this has reached resolution! Apparently the linear bearing sided in my year's Desktop production were succeptible to degradation from two very specific dust types: pine and corian. Almost ever single test I did while learning was done in cheap, Home Depot pine... sigh.
    Good news: since these bearings are no longer used they have a few spare that they were happpy to send me and help me with some other stuff to keep ALL dust off my rails.

    They've been super helpful! Will update once I've made the swaps.
    Chris

  6. #26
    Join Date
    Feb 2016
    Posts
    44

    Default

    Ok, so I replaced all the bearings on either side of my Desktop but am just now getting around to actually testing them. I'm still not convinced I've gotten everything covered though. I wanted to include a video of some strange. Poses the machine makes sometimes when moving on a diagonal path. It is still doing it after the bearing swap so I figured I'd see if people had any opinions on it:

    Thoughts?
    Chris

  7. #27
    Join Date
    Apr 2013
    Location
    Kennebunkport, Maine
    Posts
    3,983

    Default

    What's the Move Speed on that roughing move?
    I've had similar sound/vibration on radio button moves in that direction(I forget the MS) and changing MS down .2IPS made it smooth again.
    Maybe run the aircut, and using Shift(holding it down) and the < > keys to see if a few .1 IPS changes makes it run smooth, and then mod the the file MS and spindle speed?
    Every machine has slightly different spots with bad resonance, and seems you found one.
    scott
    Scott Plaisted
    2013 Desktop/spindle/VCP 9
    Maine

  8. #28
    Join Date
    Feb 2016
    Posts
    44

    Default

    Changing the speed did not have an impact on the vibration on the two legs where it does it... at least not in a positive sense. If anything things got worse as the feed was slowed.
    I can do another video if it helps? But I don't know how much will be learned from seeing it do the same, just at a different pitch, from the last video.
    Chris

  9. #29
    Join Date
    Dec 2000
    Location
    Thorp, WI
    Posts
    2,610

    Default

    Have you checked into adjusting the pots on the drivers? You may be able to dial out some of that resonance.
    Scott



  10. #30
    Join Date
    Feb 2016
    Posts
    44

    Default

    No, I'm fairly new to this whole thing so a lot of this stuff, like adjusting pot values?, is Greek to me.
    The reason I thought this might be an issue isn't because it's ever failed while making that noise... but instead both times it has failed has been when I've been milling something along a center-line that's a diagonal between the lower left and upper right of the table. Moving along this line is when it sometimes makes that noise and vibration... moving along the X-axis for a part along that line on a finishing pass is when it has failed both times.
    Chris

Similar Threads

  1. Movie About the Z-axis Skipping
    By Chazz in forum ShopBot Desktop
    Replies: 16
    Last Post: 08-04-2015, 09:53 PM
  2. Skipping/Chattering/???, etc....on Y axis movement
    By Adam Buchwald in forum ShopBot Buddy
    Replies: 3
    Last Post: 04-26-2015, 01:25 PM
  3. Z axis zeroing and drifting deeper problems
    By bbobmc in forum Troubleshooting
    Replies: 6
    Last Post: 04-12-2015, 11:49 PM
  4. X-Axis is Jittery/Skipping
    By MitchTalmadge in forum Troubleshooting
    Replies: 14
    Last Post: 10-14-2014, 08:43 PM
  5. Z axis skipping
    By BulletTrap in forum ShopBotter Message Board
    Replies: 4
    Last Post: 05-06-2010, 11:01 AM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •